Consistent use of @Nullable across the codebase (even for internals)

Beyond just formally declaring the current behavior, this revision actually enforces non-null behavior in selected signatures now, not tolerating null values anymore when not explicitly documented. It also changes some utility methods with historic null-in/null-out tolerance towards enforced non-null return values, making them a proper citizen in non-null assignments.

Some issues are left as to-do: in particular a thorough revision of spring-test, and a few tests with unclear failures (ignored as "TODO: NULLABLE") to be sorted out in a follow-up commit.

Issue: SPR-15540

spring-aop/src/main/java/org/springframework/aop/Advisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-aop/src/main/java/org/springframework/aop/TargetSource.java

@@ -1,5 +1,5 @@
 /*<
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,14 +31,14 @@ import org.springframework.lang.Nullable;
  * {@code TargetSources} directly: this is an AOP framework interface.
  *
  * @author Rod Johnson
+ * @author Juergen Hoeller
  */
 public interface TargetSource extends TargetClassAware {
 
 	/**
 	 * Return the type of targets returned by this {@link TargetSource}.
-	 * <p>Can return {@code null}, although certain usages of a
+	 * <p>Can return {@code null}, although certain usages of a {@code TargetSource}
-	 * {@code TargetSource} might just work with a predetermined
+	 * might just work with a predetermined target class.
-	 * target class.
 	 * @return the type of targets returned by this {@link TargetSource}
 	 */
 	@Override
@@ -46,9 +46,8 @@ public interface TargetSource extends TargetClassAware {
 
 	/**
 	 * Will all calls to {@link #getTarget()} return the same object?
-	 * <p>In that case, there will be no need to invoke
+	 * <p>In that case, there will be no need to invoke {@link #releaseTarget(Object)},
-	 * {@link #releaseTarget(Object)}, and the AOP framework can cache
+	 * and the AOP framework can cache the return value of {@link #getTarget()}.
-	 * the return value of {@link #getTarget()}.
 	 * @return {@code true} if the target is immutable
 	 * @see #getTarget
 	 */

spring-aop/src/main/java/org/springframework/aop/aspectj/AbstractAspectJAdvice.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -208,6 +208,7 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 	/**
 	 * Return the ClassLoader for aspect instances.
 	 */
+	@Nullable
 	public final ClassLoader getAspectClassLoader() {
 		return this.aspectInstanceFactory.getAspectClassLoader();
 	}
@@ -296,8 +297,8 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 			}
 			catch (Throwable ex) {
 				throw new IllegalArgumentException("Returning name '" + name  +
-						"' is neither a valid argument name nor the fully-qualified name of a Java type on the classpath. " +
+						"' is neither a valid argument name nor the fully-qualified " +
-						"Root cause: " + ex);
+						"name of a Java type on the classpath. Root cause: " + ex);
 			}
 		}
 	}
@@ -306,6 +307,7 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 		return this.discoveredReturningType;
 	}
 
+	@Nullable
 	protected Type getDiscoveredReturningGenericType() {
 		return this.discoveredReturningGenericType;
 	}
@@ -330,8 +332,8 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 			}
 			catch (Throwable ex) {
 				throw new IllegalArgumentException("Throwing name '" + name  +
-						"' is neither a valid argument name nor the fully-qualified name of a Java type on the classpath. " +
+						"' is neither a valid argument name nor the fully-qualified " +
-						"Root cause: " + ex);
+						"name of a Java type on the classpath. Root cause: " + ex);
 			}
 		}
 	}
@@ -549,7 +551,9 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 	 * @param ex the exception thrown by the method execution (may be null)
 	 * @return the empty array if there are no arguments
 	 */
-	protected Object[] argBinding(JoinPoint jp, JoinPointMatch jpMatch, @Nullable Object returnValue, @Nullable Throwable ex) {
+	protected Object[] argBinding(JoinPoint jp, @Nullable JoinPointMatch jpMatch,
+			@Nullable Object returnValue, @Nullable Throwable ex) {
+
 		calculateArgumentBindings();
 
 		// AMC start
@@ -608,13 +612,16 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 	 * @return the invocation result
 	 * @throws Throwable in case of invocation failure
 	 */
-	protected Object invokeAdviceMethod(JoinPointMatch jpMatch, @Nullable Object returnValue, @Nullable Throwable ex) throws Throwable {
+	protected Object invokeAdviceMethod(
+			@Nullable JoinPointMatch jpMatch, @Nullable Object returnValue, @Nullable Throwable ex)
+			throws Throwable {
+
 		return invokeAdviceMethodWithGivenArgs(argBinding(getJoinPoint(), jpMatch, returnValue, ex));
 	}
 
 	// As above, but in this case we are given the join point.
-	protected Object invokeAdviceMethod(JoinPoint jp, JoinPointMatch jpMatch, Object returnValue, Throwable t)
+	protected Object invokeAdviceMethod(JoinPoint jp, @Nullable JoinPointMatch jpMatch,
-			throws Throwable {
+			@Nullable Object returnValue, @Nullable Throwable t) throws Throwable {
 
 		return invokeAdviceMethodWithGivenArgs(argBinding(jp, jpMatch, returnValue, t));
 	}
@@ -649,6 +656,7 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 	/**
 	 * Get the current join point match at the join point we are being dispatched on.
 	 */
+	@Nullable
 	protected JoinPointMatch getJoinPointMatch() {
 		MethodInvocation mi = ExposeInvocationInterceptor.currentInvocation();
 		if (!(mi instanceof ProxyMethodInvocation)) {
@@ -663,8 +671,10 @@ public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedence
 	// 'last man wins' which is not what we want at all.
 	// Using the expression is guaranteed to be safe, since 2 identical expressions
 	// are guaranteed to bind in exactly the same way.
+	@Nullable
 	protected JoinPointMatch getJoinPointMatch(ProxyMethodInvocation pmi) {
-		return (JoinPointMatch) pmi.getUserAttribute(this.pointcut.getExpression());
+		String expression = this.pointcut.getExpression();
+		return (expression != null ? (JoinPointMatch) pmi.getUserAttribute(expression) : null);
 	}
 
 

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectInstanceFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.aop.aspectj;
 
 import org.springframework.core.Ordered;
+import org.springframework.lang.Nullable;
 
 /**
  * Interface implemented to provide an instance of an AspectJ aspect.
@@ -40,8 +41,10 @@ public interface AspectInstanceFactory extends Ordered {
 
 	/**
 	 * Expose the aspect class loader that this factory uses.
-	 * @return the aspect class loader (never {@code null})
+	 * @return the aspect class loader (or {@code null} for the bootstrap loader)
+	 * @see org.springframework.util.ClassUtils#getDefaultClassLoader()
 	 */
+	@Nullable
 	ClassLoader getAspectClassLoader();
 
 }

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJAdviceParameterNameDiscoverer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -183,10 +183,11 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	 * Create a new discoverer that attempts to discover parameter names
 	 * from the given pointcut expression.
 	 */
-	public AspectJAdviceParameterNameDiscoverer(String pointcutExpression) {
+	public AspectJAdviceParameterNameDiscoverer(@Nullable String pointcutExpression) {
 		this.pointcutExpression = pointcutExpression;
 	}
 
+
 	/**
 	 * Indicate whether {@link IllegalArgumentException} and {@link AmbiguousBindingException}
 	 * must be thrown as appropriate in the case of failing to deduce advice parameter names.
@@ -214,6 +215,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 		this.throwingName = throwingName;
 	}
 
+
 	/**
 	 * Deduce the parameter names for an advice method.
 	 * <p>See the {@link AspectJAdviceParameterNameDiscoverer class level javadoc}
@@ -475,8 +477,8 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	 * If the token starts meets Java identifier conventions, it's in.
 	 */
 	@Nullable
-	private String maybeExtractVariableName(String candidateToken) {
+	private String maybeExtractVariableName(@Nullable String candidateToken) {
-		if (candidateToken == null || candidateToken.equals("")) {
+		if (!StringUtils.hasLength(candidateToken)) {
 			return null;
 		}
 		if (Character.isJavaIdentifierStart(candidateToken.charAt(0)) &&
@@ -498,7 +500,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	 * Given an args pointcut body (could be {@code args} or {@code at_args}),
 	 * add any candidate variable names to the given list.
 	 */
-	private void maybeExtractVariableNamesFromArgs(String argsSpec, List<String> varNames) {
+	private void maybeExtractVariableNamesFromArgs(@Nullable String argsSpec, List<String> varNames) {
 		if (argsSpec == null) {
 			return;
 		}
@@ -781,7 +783,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 
 		private String text;
 
-		public PointcutBody(int tokens, String text) {
+		public PointcutBody(int tokens, @Nullable String text) {
 			this.numTokensConsumed = tokens;
 			this.text = text;
 		}

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJAroundAdvice.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -57,6 +57,7 @@ import org.springframework.beans.factory.FactoryBean;
 import org.springframework.beans.factory.annotation.BeanFactoryAnnotationUtils;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
@@ -196,6 +197,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 	/**
 	 * Determine the ClassLoader to use for pointcut evaluation.
 	 */
+	@Nullable
 	private ClassLoader determinePointcutClassLoader() {
 		if (this.beanFactory instanceof ConfigurableBeanFactory) {
 			return ((ConfigurableBeanFactory) this.beanFactory).getBeanClassLoader();
@@ -209,21 +211,27 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 	/**
 	 * Build the underlying AspectJ pointcut expression.
 	 */
-	private PointcutExpression buildPointcutExpression(ClassLoader classLoader) {
+	private PointcutExpression buildPointcutExpression(@Nullable ClassLoader classLoader) {
 		PointcutParser parser = initializePointcutParser(classLoader);
 		PointcutParameter[] pointcutParameters = new PointcutParameter[this.pointcutParameterNames.length];
 		for (int i = 0; i < pointcutParameters.length; i++) {
 			pointcutParameters[i] = parser.createPointcutParameter(
 					this.pointcutParameterNames[i], this.pointcutParameterTypes[i]);
 		}
-		return parser.parsePointcutExpression(replaceBooleanOperators(getExpression()),
+		return parser.parsePointcutExpression(replaceBooleanOperators(resolveExpression()),
 				this.pointcutDeclarationScope, pointcutParameters);
 	}
 
+	private String resolveExpression() {
+		String expression = getExpression();
+		Assert.state(expression != null, "No expression set");
+		return expression;
+	}
+
 	/**
 	 * Initialize the underlying AspectJ pointcut parser.
 	 */
-	private PointcutParser initializePointcutParser(ClassLoader classLoader) {
+	private PointcutParser initializePointcutParser(@Nullable ClassLoader classLoader) {
 		PointcutParser parser = PointcutParser
 				.getPointcutParserSupportingSpecifiedPrimitivesAndUsingSpecifiedClassLoaderForResolution(
 						SUPPORTED_PRIMITIVES, classLoader);
@@ -301,7 +309,8 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 			// we say this is not a match as in Spring there will never be a different
 			// runtime subtype.
 			RuntimeTestWalker walker = getRuntimeTestWalker(shadowMatch);
-			return (!walker.testsSubtypeSensitiveVars() || walker.testTargetInstanceOfResidue(targetClass));
+			return (!walker.testsSubtypeSensitiveVars() ||
+					(targetClass != null && walker.testTargetInstanceOfResidue(targetClass)));
 		}
 	}
 
@@ -354,7 +363,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 			 * type but not 'this' (as would be the case of JDK dynamic proxies).
 			 * <p>See SPR-2979 for the original bug.
 			 */
-			if (pmi != null) {  // there is a current invocation
+			if (pmi != null && thisObject != null) {  // there is a current invocation
 				RuntimeTestWalker originalMethodResidueTest = getRuntimeTestWalker(originalShadowMatch);
 				if (!originalMethodResidueTest.testThisInstanceOfResidue(thisObject.getClass())) {
 					return false;
@@ -375,6 +384,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 		}
 	}
 
+	@Nullable
 	protected String getCurrentProxiedBeanName() {
 		return ProxyCreationContext.getCurrentProxiedBeanName();
 	}
@@ -411,7 +421,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 		// 'last man wins' which is not what we want at all.
 		// Using the expression is guaranteed to be safe, since 2 identical expressions
 		// are guaranteed to bind in exactly the same way.
-		invocation.setUserAttribute(getExpression(), jpm);
+		invocation.setUserAttribute(resolveExpression(), jpm);
 	}
 
 	private ShadowMatch getShadowMatch(Method targetMethod, Method originalMethod) {
@@ -600,7 +610,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 			return false;
 		}
 
-		private FuzzyBoolean contextMatch(Class<?> targetType) {
+		private FuzzyBoolean contextMatch(@Nullable Class<?> targetType) {
 			String advisedBeanName = getCurrentProxiedBeanName();
 			if (advisedBeanName == null) {  // no proxy creation in progress
 				// abstain; can't return YES, since that will make pointcut with negation fail

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcutAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import org.springframework.aop.Pointcut;
 import org.springframework.aop.support.AbstractGenericPointcutAdvisor;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.lang.Nullable;
 
 /**
  * Spring AOP Advisor that can be used for any AspectJ pointcut expression.
@@ -37,6 +38,7 @@ public class AspectJExpressionPointcutAdvisor extends AbstractGenericPointcutAdv
 		this.pointcut.setExpression(expression);
 	}
 
+	@Nullable
 	public String getExpression() {
 		return this.pointcut.getExpression();
 	}
@@ -45,6 +47,7 @@ public class AspectJExpressionPointcutAdvisor extends AbstractGenericPointcutAdv
 		this.pointcut.setLocation(location);
 	}
 
+	@Nullable
 	public String getLocation() {
 		return this.pointcut.getLocation();
 	}

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/AbstractAspectJAdvisorFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -212,6 +212,7 @@ public abstract class AbstractAspectJAdvisorFactory implements AspectJAdvisorFac
 			throw new IllegalStateException("Unknown annotation type: " + annotation.toString());
 		}
 
+		@Nullable
 		private String resolveExpression(A annotation) throws Exception {
 			String expression = null;
 			for (String methodName : EXPRESSION_PROPERTIES) {

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/AspectJProxyFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -119,7 +119,9 @@ public class AspectJProxyFactory extends ProxyCreatorSupport {
 	 */
 	private void addAdvisorsFromAspectInstanceFactory(MetadataAwareAspectInstanceFactory instanceFactory) {
 		List<Advisor> advisors = this.aspectFactory.getAdvisors(instanceFactory);
-		advisors = AopUtils.findAdvisorsThatCanApply(advisors, getTargetClass());
+		Class<?> targetClass = getTargetClass();
+		Assert.state(targetClass != null, "Unresolvable target class");
+		advisors = AopUtils.findAdvisorsThatCanApply(advisors, targetClass);
 		AspectJProxyUtils.makeAdvisorChainAspectJCapableIfNecessary(advisors);
 		AnnotationAwareOrderComparator.sort(advisors);
 		addAdvisors(advisors);

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/BeanFactoryAspectInstanceFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.OrderUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -58,7 +59,7 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 	 * @param name name of the bean
 	 */
 	public BeanFactoryAspectInstanceFactory(BeanFactory beanFactory, String name) {
-		this(beanFactory, name, beanFactory.getType(name));
+		this(beanFactory, name, null);
 	}
 
 	/**
@@ -68,13 +69,19 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 	 * @param beanFactory BeanFactory to obtain instance(s) from
 	 * @param name the name of the bean
 	 * @param type the type that should be introspected by AspectJ
+	 * ({@code null} indicates resolution through {@link BeanFactory#getType} via the bean name)
 	 */
-	public BeanFactoryAspectInstanceFactory(BeanFactory beanFactory, String name, Class<?> type) {
+	public BeanFactoryAspectInstanceFactory(BeanFactory beanFactory, String name, @Nullable Class<?> type) {
 		Assert.notNull(beanFactory, "BeanFactory must not be null");
 		Assert.notNull(name, "Bean name must not be null");
 		this.beanFactory = beanFactory;
 		this.name = name;
-		this.aspectMetadata = new AspectMetadata(type, name);
+		Class<?> resolvedType = type;
+		if (type == null) {
+			resolvedType = beanFactory.getType(name);
+			Assert.notNull(resolvedType, "Unresolvable bean type - explicitly specify the aspect class");
+		}
+		this.aspectMetadata = new AspectMetadata(resolvedType, name);
 	}
 
 

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/InstantiationModelAwarePointcutAdvisorImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,6 +45,9 @@ import org.springframework.lang.Nullable;
 class InstantiationModelAwarePointcutAdvisorImpl
 		implements InstantiationModelAwarePointcutAdvisor, AspectJPrecedenceInformation, Serializable {
 
+	private static Advice EMPTY_ADVICE = new Advice() {};
+
+
 	private final AspectJExpressionPointcut declaredPointcut;
 
 	private final Class<?> declaringClass;
@@ -157,9 +160,10 @@ class InstantiationModelAwarePointcutAdvisorImpl
 	}
 
 
-	private Advice instantiateAdvice(AspectJExpressionPointcut pcut) {
+	private Advice instantiateAdvice(AspectJExpressionPointcut pointcut) {
-		return this.aspectJAdvisorFactory.getAdvice(this.aspectJAdviceMethod, pcut,
+		Advice advice = this.aspectJAdvisorFactory.getAdvice(this.aspectJAdviceMethod, pointcut,
 				this.aspectInstanceFactory, this.declarationOrder, this.aspectName);
+		return (advice != null ? advice : EMPTY_ADVICE);
 	}
 
 	public MetadataAwareAspectInstanceFactory getAspectInstanceFactory() {

spring-aop/src/main/java/org/springframework/aop/aspectj/autoproxy/AspectJPrecedenceComparator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -132,7 +132,9 @@ class AspectJPrecedenceComparator implements Comparator<Advisor> {
 
 	// pre-condition is that hasAspectName returned true
 	private String getAspectName(Advisor anAdvisor) {
-		return AspectJAopUtils.getAspectJPrecedenceInformationFor(anAdvisor).getAspectName();
+		AspectJPrecedenceInformation pi = AspectJAopUtils.getAspectJPrecedenceInformationFor(anAdvisor);
+		Assert.state(pi != null, "Unresolvable precedence information");
+		return pi.getAspectName();
 	}
 
 	private int getAspectDeclarationOrder(Advisor anAdvisor) {

spring-aop/src/main/java/org/springframework/aop/config/AbstractInterceptorDrivenBeanDefinitionDecorator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,7 @@ import org.springframework.beans.factory.support.ManagedList;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.factory.xml.BeanDefinitionDecorator;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
@@ -105,8 +106,8 @@ public abstract class AbstractInterceptorDrivenBeanDefinitionDecorator implement
 
 	@SuppressWarnings("unchecked")
 	private void addInterceptorNameToList(String interceptorName, BeanDefinition beanDefinition) {
-		List<String> list = (List<String>)
+		List<String> list = (List<String>) beanDefinition.getPropertyValues().get("interceptorNames");
-				beanDefinition.getPropertyValues().getPropertyValue("interceptorNames").getValue();
+		Assert.state(list != null, "Missing 'interceptorNames' property");
 		list.add(interceptorName);
 	}
 
@@ -115,7 +116,9 @@ public abstract class AbstractInterceptorDrivenBeanDefinitionDecorator implement
 	}
 
 	protected String getInterceptorNameSuffix(BeanDefinition interceptorDefinition) {
-		return StringUtils.uncapitalize(ClassUtils.getShortName(interceptorDefinition.getBeanClassName()));
+		String beanClassName = interceptorDefinition.getBeanClassName();
+		return (StringUtils.hasLength(beanClassName) ?
+				StringUtils.uncapitalize(ClassUtils.getShortName(beanClassName)) : "");
 	}
 
 	/**

spring-aop/src/main/java/org/springframework/aop/config/AdvisorComponentDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanReference;
 import org.springframework.beans.factory.parsing.AbstractComponentDefinition;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -50,7 +51,7 @@ public class AdvisorComponentDefinition extends AbstractComponentDefinition {
 	}
 
 	public AdvisorComponentDefinition(
-			String advisorBeanName, BeanDefinition advisorDefinition, BeanDefinition pointcutDefinition) {
+			String advisorBeanName, BeanDefinition advisorDefinition, @Nullable BeanDefinition pointcutDefinition) {
 
 		Assert.notNull(advisorBeanName, "'advisorBeanName' must not be null");
 		Assert.notNull(advisorDefinition, "'advisorDefinition' must not be null");
@@ -60,9 +61,10 @@ public class AdvisorComponentDefinition extends AbstractComponentDefinition {
 	}
 
 
-	private void unwrapDefinitions(BeanDefinition advisorDefinition, BeanDefinition pointcutDefinition) {
+	private void unwrapDefinitions(BeanDefinition advisorDefinition, @Nullable BeanDefinition pointcutDefinition) {
 		MutablePropertyValues pvs = advisorDefinition.getPropertyValues();
-		BeanReference adviceReference = (BeanReference) pvs.getPropertyValue("adviceBeanName").getValue();
+		BeanReference adviceReference = (BeanReference) pvs.get("adviceBeanName");
+		Assert.state(adviceReference != null, "Missing 'adviceBeanName' property");
 
 		if (pointcutDefinition != null) {
 			this.beanReferences = new BeanReference[] {adviceReference};
@@ -70,7 +72,8 @@ public class AdvisorComponentDefinition extends AbstractComponentDefinition {
 			this.description = buildDescription(adviceReference, pointcutDefinition);
 		}
 		else {
-			BeanReference pointcutReference = (BeanReference) pvs.getPropertyValue("pointcut").getValue();
+			BeanReference pointcutReference = (BeanReference) pvs.get("pointcut");
+			Assert.state(pointcutReference != null, "Missing 'pointcut' property");
 			this.beanReferences = new BeanReference[] {adviceReference, pointcutReference};
 			this.beanDefinitions = new BeanDefinition[] {advisorDefinition};
 			this.description = buildDescription(adviceReference, pointcutReference);
@@ -78,16 +81,15 @@ public class AdvisorComponentDefinition extends AbstractComponentDefinition {
 	}
 
 	private String buildDescription(BeanReference adviceReference, BeanDefinition pointcutDefinition) {
-		return new StringBuilder("Advisor <advice(ref)='").
+		return "Advisor <advice(ref)='" +
-				append(adviceReference.getBeanName()).append("', pointcut(expression)=[").
+				adviceReference.getBeanName() + "', pointcut(expression)=[" +
-				append(pointcutDefinition.getPropertyValues().getPropertyValue("expression").getValue()).
+				pointcutDefinition.getPropertyValues().get("expression") + "]>";
-				append("]>").toString();
 	}
 
 	private String buildDescription(BeanReference adviceReference, BeanReference pointcutReference) {
-		return new StringBuilder("Advisor <advice(ref)='").
+		return "Advisor <advice(ref)='" +
-				append(adviceReference.getBeanName()).append("', pointcut(ref)='").
+				adviceReference.getBeanName() + "', pointcut(ref)='" +
-				append(pointcutReference.getBeanName()).append("'>").toString();
+				pointcutReference.getBeanName() + "'>";
 	}
 
 

spring-aop/src/main/java/org/springframework/aop/config/AopConfigUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -67,27 +67,39 @@ public abstract class AopConfigUtils {
 	}
 
 
+	@Nullable
 	public static BeanDefinition registerAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry) {
 		return registerAutoProxyCreatorIfNecessary(registry, null);
 	}
 
-	public static BeanDefinition registerAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, Object source) {
+	@Nullable
+	public static BeanDefinition registerAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry,
+			@Nullable Object source) {
+
 		return registerOrEscalateApcAsRequired(InfrastructureAdvisorAutoProxyCreator.class, registry, source);
 	}
 
+	@Nullable
 	public static BeanDefinition registerAspectJAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry) {
 		return registerAspectJAutoProxyCreatorIfNecessary(registry, null);
 	}
 
-	public static BeanDefinition registerAspectJAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, Object source) {
+	@Nullable
+	public static BeanDefinition registerAspectJAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry,
+			@Nullable Object source) {
+
 		return registerOrEscalateApcAsRequired(AspectJAwareAdvisorAutoProxyCreator.class, registry, source);
 	}
 
+	@Nullable
 	public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry) {
 		return registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry, null);
 	}
 
-	public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, Object source) {
+	@Nullable
+	public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry,
+			@Nullable Object source) {
+
 		return registerOrEscalateApcAsRequired(AnnotationAwareAspectJAutoProxyCreator.class, registry, source);
 	}
 
@@ -106,8 +118,11 @@ public abstract class AopConfigUtils {
 	}
 
 	@Nullable
-	private static BeanDefinition registerOrEscalateApcAsRequired(Class<?> cls, BeanDefinitionRegistry registry, Object source) {
+	private static BeanDefinition registerOrEscalateApcAsRequired(Class<?> cls, BeanDefinitionRegistry registry,
+			@Nullable Object source) {
+
 		Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
+
 		if (registry.containsBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME)) {
 			BeanDefinition apcDefinition = registry.getBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME);
 			if (!cls.getName().equals(apcDefinition.getBeanClassName())) {
@@ -119,6 +134,7 @@ public abstract class AopConfigUtils {
 			}
 			return null;
 		}
+
 		RootBeanDefinition beanDefinition = new RootBeanDefinition(cls);
 		beanDefinition.setSource(source);
 		beanDefinition.getPropertyValues().add("order", Ordered.HIGHEST_PRECEDENCE);
@@ -131,7 +147,7 @@ public abstract class AopConfigUtils {
 		return APC_PRIORITY_LIST.indexOf(clazz);
 	}
 
-	private static int findPriorityForClass(String className) {
+	private static int findPriorityForClass(@Nullable String className) {
 		for (int i = 0; i < APC_PRIORITY_LIST.size(); i++) {
 			Class<?> clazz = APC_PRIORITY_LIST.get(i);
 			if (clazz.getName().equals(className)) {

spring-aop/src/main/java/org/springframework/aop/config/AopNamespaceUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.parsing.BeanComponentDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.lang.Nullable;
 
 /**
  * Utility class for handling registration of auto-proxy creators used internally
@@ -79,7 +80,7 @@ public abstract class AopNamespaceUtils {
 		registerComponentIfNecessary(beanDefinition, parserContext);
 	}
 
-	private static void useClassProxyingIfNecessary(BeanDefinitionRegistry registry, Element sourceElement) {
+	private static void useClassProxyingIfNecessary(BeanDefinitionRegistry registry, @Nullable Element sourceElement) {
 		if (sourceElement != null) {
 			boolean proxyTargetClass = Boolean.valueOf(sourceElement.getAttribute(PROXY_TARGET_CLASS_ATTRIBUTE));
 			if (proxyTargetClass) {
@@ -92,7 +93,7 @@ public abstract class AopNamespaceUtils {
 		}
 	}
 
-	private static void registerComponentIfNecessary(BeanDefinition beanDefinition, ParserContext parserContext) {
+	private static void registerComponentIfNecessary(@Nullable BeanDefinition beanDefinition, ParserContext parserContext) {
 		if (beanDefinition != null) {
 			BeanComponentDefinition componentDefinition =
 					new BeanComponentDefinition(beanDefinition, AopConfigUtils.AUTO_PROXY_CREATOR_BEAN_NAME);

spring-aop/src/main/java/org/springframework/aop/config/AspectComponentDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ package org.springframework.aop.config;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanReference;
 import org.springframework.beans.factory.parsing.CompositeComponentDefinition;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link org.springframework.beans.factory.parsing.ComponentDefinition}
@@ -37,8 +38,8 @@ public class AspectComponentDefinition extends CompositeComponentDefinition {
 	private final BeanReference[] beanReferences;
 
 
-	public AspectComponentDefinition(
+	public AspectComponentDefinition(String aspectName, @Nullable BeanDefinition[] beanDefinitions,
-			String aspectName, BeanDefinition[] beanDefinitions, BeanReference[] beanReferences, Object source) {
+			@Nullable BeanReference[] beanReferences, @Nullable Object source) {
 
 		super(aspectName, source);
 		this.beanDefinitions = (beanDefinitions != null ? beanDefinitions : new BeanDefinition[0]);

spring-aop/src/main/java/org/springframework/aop/framework/AbstractSingletonProxyFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -124,7 +124,7 @@ public abstract class AbstractSingletonProxyFactoryBean extends ProxyConfig
 	}
 
 	@Override
-	public void setBeanClassLoader(@Nullable ClassLoader classLoader) {
+	public void setBeanClassLoader(ClassLoader classLoader) {
 		if (this.proxyClassLoader == null) {
 			this.proxyClassLoader = classLoader;
 		}
@@ -170,8 +170,10 @@ public abstract class AbstractSingletonProxyFactoryBean extends ProxyConfig
 		}
 		else if (!isProxyTargetClass()) {
 			// Rely on AOP infrastructure to tell us what interfaces to proxy.
-			proxyFactory.setInterfaces(
+			Class<?> targetClass = targetSource.getTargetClass();
-					ClassUtils.getAllInterfacesForClass(targetSource.getTargetClass(), this.proxyClassLoader));
+			if (targetClass != null) {
+				proxyFactory.setInterfaces(ClassUtils.getAllInterfacesForClass(targetClass, this.proxyClassLoader));
+			}
 		}
 
 		postProcessProxyFactory(proxyFactory);

spring-aop/src/main/java/org/springframework/aop/framework/AdvisedSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,7 @@ import org.springframework.aop.support.DefaultIntroductionAdvisor;
 import org.springframework.aop.support.DefaultPointcutAdvisor;
 import org.springframework.aop.target.EmptyTargetSource;
 import org.springframework.aop.target.SingletonTargetSource;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
@@ -137,7 +138,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 	}
 
 	@Override
-	public void setTargetSource(TargetSource targetSource) {
+	public void setTargetSource(@Nullable TargetSource targetSource) {
 		this.targetSource = (targetSource != null ? targetSource : EMPTY_TARGET_SOURCE);
 	}
 
@@ -446,7 +447,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 	 * @param advice the advice to check inclusion of
 	 * @return whether this advice instance is included
 	 */
-	public boolean adviceIncluded(Advice advice) {
+	public boolean adviceIncluded(@Nullable Advice advice) {
 		if (advice != null) {
 			for (Advisor advisor : this.advisors) {
 				if (advisor.getAdvice() == advice) {
@@ -462,7 +463,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 	 * @param adviceClass the advice class to check
 	 * @return the count of the interceptors of this class or subclasses
 	 */
-	public int countAdvicesOfType(Class<?> adviceClass) {
+	public int countAdvicesOfType(@Nullable Class<?> adviceClass) {
 		int count = 0;
 		if (adviceClass != null) {
 			for (Advisor advisor : this.advisors) {
@@ -482,7 +483,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 	 * @param targetClass the target class
 	 * @return List of MethodInterceptors (may also include InterceptorAndDynamicMethodMatchers)
 	 */
-	public List<Object> getInterceptorsAndDynamicInterceptionAdvice(Method method, Class<?> targetClass) {
+	public List<Object> getInterceptorsAndDynamicInterceptionAdvice(Method method, @Nullable Class<?> targetClass) {
 		MethodCacheKey cacheKey = new MethodCacheKey(method);
 		List<Object> cached = this.methodCache.get(cacheKey);
 		if (cached == null) {

spring-aop/src/main/java/org/springframework/aop/framework/CglibAopProxy.java

@@ -134,7 +134,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 	 * @param constructorArgs the constructor argument values
 	 * @param constructorArgTypes the constructor argument types
 	 */
-	public void setConstructorArguments(Object[] constructorArgs, Class<?>[] constructorArgTypes) {
+	public void setConstructorArguments(@Nullable Object[] constructorArgs, @Nullable Class<?>[] constructorArgTypes) {
 		if (constructorArgs == null || constructorArgTypes == null) {
 			throw new IllegalArgumentException("Both 'constructorArgs' and 'constructorArgTypes' need to be specified");
 		}
@@ -233,7 +233,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 	 * Checks to see whether the supplied {@code Class} has already been validated and
 	 * validates it if not.
 	 */
-	private void validateClassIfNecessary(Class<?> proxySuperClass, ClassLoader proxyClassLoader) {
+	private void validateClassIfNecessary(Class<?> proxySuperClass, @Nullable ClassLoader proxyClassLoader) {
 		if (logger.isWarnEnabled()) {
 			synchronized (validatedClasses) {
 				if (!validatedClasses.containsKey(proxySuperClass)) {
@@ -249,7 +249,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 	 * Checks for final methods on the given {@code Class}, as well as package-visible
 	 * methods across ClassLoaders, and writes warnings to the log for each one found.
 	 */
-	private void doValidateClass(Class<?> proxySuperClass, ClassLoader proxyClassLoader, Set<Class<?>> ifcs) {
+	private void doValidateClass(Class<?> proxySuperClass, @Nullable ClassLoader proxyClassLoader, Set<Class<?>> ifcs) {
 		if (proxySuperClass != Object.class) {
 			Method[] methods = proxySuperClass.getDeclaredMethods();
 			for (Method method : methods) {
@@ -374,7 +374,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 	 * {@code proxy} and also verifies that {@code null} is not returned as a primitive.
 	 */
 	@Nullable
-	private static Object processReturnType(Object proxy, Object target, Method method, @Nullable Object retVal) {
+	private static Object processReturnType(Object proxy, @Nullable Object target, Method method, @Nullable Object retVal) {
 		// Massage return value if necessary
 		if (retVal != null && retVal == target &&
 				!RawTargetAccess.class.isAssignableFrom(method.getDeclaringClass())) {
@@ -409,11 +409,12 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final Object target;
 
-		public StaticUnadvisedInterceptor(Object target) {
+		public StaticUnadvisedInterceptor(@Nullable Object target) {
 			this.target = target;
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			Object retVal = methodProxy.invoke(this.target, args);
 			return processReturnType(proxy, this.target, method, retVal);
@@ -429,11 +430,12 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final Object target;
 
-		public StaticUnadvisedExposedInterceptor(Object target) {
+		public StaticUnadvisedExposedInterceptor(@Nullable Object target) {
 			this.target = target;
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			Object oldProxy = null;
 			try {
@@ -462,6 +464,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			Object target = this.targetSource.getTarget();
 			try {
@@ -469,7 +472,9 @@ class CglibAopProxy implements AopProxy, Serializable {
 				return processReturnType(proxy, target, method, retVal);
 			}
 			finally {
-				this.targetSource.releaseTarget(target);
+				if (target != null) {
+					this.targetSource.releaseTarget(target);
+				}
 			}
 		}
 	}
@@ -487,6 +492,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			Object oldProxy = null;
 			Object target = this.targetSource.getTarget();
@@ -497,7 +503,9 @@ class CglibAopProxy implements AopProxy, Serializable {
 			}
 			finally {
 				AopContext.setCurrentProxy(oldProxy);
-				this.targetSource.releaseTarget(target);
+				if (target != null) {
+					this.targetSource.releaseTarget(target);
+				}
 			}
 		}
 	}
@@ -512,7 +520,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private Object target;
 
-		public StaticDispatcher(Object target) {
+		public StaticDispatcher(@Nullable Object target) {
 			this.target = target;
 		}
 
@@ -604,13 +612,16 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final Class<?> targetClass;
 
-		public FixedChainStaticTargetInterceptor(List<Object> adviceChain, Object target, Class<?> targetClass) {
+		public FixedChainStaticTargetInterceptor(
+				List<Object> adviceChain, @Nullable Object target, @Nullable Class<?> targetClass) {
+
 			this.adviceChain = adviceChain;
 			this.target = target;
 			this.targetClass = targetClass;
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			MethodInvocation invocation = new CglibMethodInvocation(proxy, this.target, method, args,
 					this.targetClass, this.adviceChain, methodProxy);
@@ -635,6 +646,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 		}
 
 		@Override
+		@Nullable
 		public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
 			Object oldProxy = null;
 			boolean setProxyContext = false;
@@ -697,6 +709,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 			return this.advised.hashCode();
 		}
 
+		@Nullable
 		protected Object getTarget() throws Exception {
 			return this.advised.getTargetSource().getTarget();
 		}
@@ -716,8 +729,9 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final boolean publicMethod;
 
-		public CglibMethodInvocation(Object proxy, Object target, Method method, Object[] arguments,
+		public CglibMethodInvocation(Object proxy, @Nullable Object target, Method method,
-				Class<?> targetClass, List<Object> interceptorsAndDynamicMethodMatchers, MethodProxy methodProxy) {
+				Object[] arguments, @Nullable Class<?> targetClass,
+				List<Object> interceptorsAndDynamicMethodMatchers, MethodProxy methodProxy) {
 
 			super(proxy, target, method, arguments, targetClass, interceptorsAndDynamicMethodMatchers);
 			this.methodProxy = methodProxy;
@@ -751,7 +765,9 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final int fixedInterceptorOffset;
 
-		public ProxyCallbackFilter(AdvisedSupport advised, Map<String, Integer> fixedInterceptorMap, int fixedInterceptorOffset) {
+		public ProxyCallbackFilter(
+				AdvisedSupport advised, Map<String, Integer> fixedInterceptorMap, int fixedInterceptorOffset) {
+
 			this.advised = advised;
 			this.fixedInterceptorMap = fixedInterceptorMap;
 			this.fixedInterceptorOffset = fixedInterceptorOffset;
@@ -859,7 +875,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 					return INVOKE_TARGET;
 				}
 				Class<?> returnType = method.getReturnType();
-				if (returnType.isAssignableFrom(targetClass)) {
+				if (targetClass != null && returnType.isAssignableFrom(targetClass)) {
 					if (logger.isDebugEnabled()) {
 						logger.debug("Method return type is assignable from target type and " +
 								"may therefore return 'this' - using INVOKE_TARGET: " + method);
@@ -886,9 +902,6 @@ class CglibAopProxy implements AopProxy, Serializable {
 			}
 			ProxyCallbackFilter otherCallbackFilter = (ProxyCallbackFilter) other;
 			AdvisedSupport otherAdvised = otherCallbackFilter.advised;
-			if (this.advised == null || otherAdvised == null) {
-				return false;
-			}
 			if (this.advised.isFrozen() != otherAdvised.isFrozen()) {
 				return false;
 			}
@@ -922,12 +935,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 		}
 
 		private boolean equalsAdviceClasses(Advisor a, Advisor b) {
-			Advice aa = a.getAdvice();
+			return (a.getAdvice().getClass() == b.getAdvice().getClass());
-			Advice ba = b.getAdvice();
-			if (aa == null || ba == null) {
-				return (aa == ba);
-			}
-			return (aa.getClass() == ba.getClass());
 		}
 
 		private boolean equalsPointcuts(Advisor a, Advisor b) {
@@ -944,9 +952,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 			Advisor[] advisors = this.advised.getAdvisors();
 			for (Advisor advisor : advisors) {
 				Advice advice = advisor.getAdvice();
-				if (advice != null) {
+				hashCode = 13 * hashCode + advice.getClass().hashCode();
-					hashCode = 13 * hashCode + advice.getClass().hashCode();
-				}
 			}
 			hashCode = 13 * hashCode + (this.advised.isFrozen() ? 1 : 0);
 			hashCode = 13 * hashCode + (this.advised.isExposeProxy() ? 1 : 0);
@@ -966,7 +972,7 @@ class CglibAopProxy implements AopProxy, Serializable {
 
 		private final ClassLoader classLoader;
 
-		public ClassLoaderAwareUndeclaredThrowableStrategy(ClassLoader classLoader) {
+		public ClassLoaderAwareUndeclaredThrowableStrategy(@Nullable ClassLoader classLoader) {
 			super(UndeclaredThrowableException.class);
 			this.classLoader = classLoader;
 		}

spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -152,6 +152,7 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 	 * unless a hook method throws an exception.
 	 */
 	@Override
+	@Nullable
 	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
 		MethodInvocation invocation;
 		Object oldProxy = null;
@@ -249,7 +250,7 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 	 * or a dynamic proxy wrapping a JdkDynamicAopProxy instance.
 	 */
 	@Override
-	public boolean equals(Object other) {
+	public boolean equals(@Nullable Object other) {
 		if (other == this) {
 			return true;
 		}

spring-aop/src/main/java/org/springframework/aop/framework/ProxyFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -220,7 +220,7 @@ public class ProxyFactoryBean extends ProxyCreatorSupport
 	}
 
 	@Override
-	public void setBeanClassLoader(@Nullable ClassLoader classLoader) {
+	public void setBeanClassLoader(ClassLoader classLoader) {
 		if (!this.classLoaderConfigured) {
 			this.proxyClassLoader = classLoader;
 		}
@@ -345,8 +345,10 @@ public class ProxyFactoryBean extends ProxyCreatorSupport
 		copy.copyConfigurationFrom(this, targetSource, freshAdvisorChain());
 		if (this.autodetectInterfaces && getProxiedInterfaces().length == 0 && !isProxyTargetClass()) {
 			// Rely on AOP infrastructure to tell us what interfaces to proxy.
-			copy.setInterfaces(
+			Class<?> targetClass = targetSource.getTargetClass();
-					ClassUtils.getAllInterfacesForClass(targetSource.getTargetClass(), this.proxyClassLoader));
+			if (targetClass != null) {
+				copy.setInterfaces(ClassUtils.getAllInterfacesForClass(targetClass, this.proxyClassLoader));
+			}
 		}
 		copy.setFrozen(this.freezeProxy);
 

spring-aop/src/main/java/org/springframework/aop/framework/ProxyProcessorSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -69,7 +69,7 @@ public class ProxyProcessorSupport extends ProxyConfig implements Ordered, BeanC
 	 * {@link org.springframework.beans.factory.BeanFactory} for loading all bean classes.
 	 * This can be overridden here for specific proxies.
 	 */
-	public void setProxyClassLoader(ClassLoader classLoader) {
+	public void setProxyClassLoader(@Nullable ClassLoader classLoader) {
 		this.proxyClassLoader = classLoader;
 		this.classLoaderConfigured = (classLoader != null);
 	}
@@ -82,7 +82,7 @@ public class ProxyProcessorSupport extends ProxyConfig implements Ordered, BeanC
 	}
 
 	@Override
-	public void setBeanClassLoader(@Nullable ClassLoader classLoader) {
+	public void setBeanClassLoader(ClassLoader classLoader) {
 		if (!this.classLoaderConfigured) {
 			this.proxyClassLoader = classLoader;
 		}

spring-aop/src/main/java/org/springframework/aop/framework/ReflectiveMethodInvocation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -103,8 +103,8 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	 * but would complicate the code. And it would work only for static pointcuts.
 	 */
 	protected ReflectiveMethodInvocation(
-			Object proxy, Object target, Method method, Object[] arguments,
+			Object proxy, @Nullable Object target, Method method, Object[] arguments,
-			Class<?> targetClass, List<Object> interceptorsAndDynamicMethodMatchers) {
+			@Nullable Class<?> targetClass, List<Object> interceptorsAndDynamicMethodMatchers) {
 
 		this.proxy = proxy;
 		this.target = target;
@@ -152,6 +152,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 
 
 	@Override
+	@Nullable
 	public Object proceed() throws Throwable {
 		//	We start with an index of -1 and increment early.
 		if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {
@@ -187,6 +188,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	 * @return the return value of the joinpoint
 	 * @throws Throwable if invoking the joinpoint resulted in an exception
 	 */
+	@Nullable
 	protected Object invokeJoinpoint() throws Throwable {
 		return AopUtils.invokeJoinpointUsingReflection(this.target, this.method, this.arguments);
 	}
@@ -220,7 +222,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	 * @see java.lang.Object#clone()
 	 */
 	@Override
-	public MethodInvocation invocableClone(Object... arguments) {
+	public MethodInvocation invocableClone(@Nullable Object... arguments) {
 		// Force initialization of the user attributes Map,
 		// for having a shared Map reference in the clone.
 		if (this.userAttributes == null) {

spring-aop/src/main/java/org/springframework/aop/framework/adapter/ThrowsAdviceInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.aop.AfterAdvice;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -103,6 +104,7 @@ public class ThrowsAdviceInterceptor implements MethodInterceptor, AfterAdvice {
 	 * @param exception the exception thrown
 	 * @return a handler for the given exception type
 	 */
+	@Nullable
 	private Method getExceptionHandler(Throwable exception) {
 		Class<?> exceptionClass = exception.getClass();
 		if (logger.isTraceEnabled()) {

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAutoProxyCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -238,7 +238,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	}
 
 	@Override
-	public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
+	public Object postProcessBeforeInstantiation(Class<?> beanClass, @Nullable String beanName) throws BeansException {
 		Object cacheKey = getCacheKey(beanClass, beanName);
 
 		if (beanName == null || !this.targetSourcedBeans.contains(beanName)) {
@@ -291,7 +291,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @see #getAdvicesAndAdvisorsForBean
 	 */
 	@Override
-	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
+	public Object postProcessAfterInitialization(@Nullable Object bean, String beanName) throws BeansException {
 		if (bean != null) {
 			Object cacheKey = getCacheKey(bean.getClass(), beanName);
 			if (!this.earlyProxyReferences.contains(cacheKey)) {
@@ -313,7 +313,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @param beanName the bean name
 	 * @return the cache key for the given class and name
 	 */
-	protected Object getCacheKey(Class<?> beanClass, String beanName) {
+	protected Object getCacheKey(Class<?> beanClass, @Nullable String beanName) {
 		if (StringUtils.hasLength(beanName)) {
 			return (FactoryBean.class.isAssignableFrom(beanClass) ?
 					BeanFactory.FACTORY_BEAN_PREFIX + beanName : beanName);
@@ -330,7 +330,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @param cacheKey the cache key for metadata access
 	 * @return a proxy wrapping the bean, or the raw bean instance as-is
 	 */
-	protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
+	protected Object wrapIfNecessary(Object bean, @Nullable String beanName, Object cacheKey) {
 		if (beanName != null && this.targetSourcedBeans.contains(beanName)) {
 			return bean;
 		}
@@ -388,7 +388,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @param beanName the name of the bean
 	 * @return whether to skip the given bean
 	 */
-	protected boolean shouldSkip(Class<?> beanClass, String beanName) {
+	protected boolean shouldSkip(Class<?> beanClass, @Nullable String beanName) {
 		return false;
 	}
 
@@ -435,8 +435,8 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @return the AOP proxy for the bean
 	 * @see #buildAdvisors
 	 */
-	protected Object createProxy(
+	protected Object createProxy(Class<?> beanClass, @Nullable String beanName,
-			Class<?> beanClass, String beanName, Object[] specificInterceptors, TargetSource targetSource) {
+			@Nullable Object[] specificInterceptors, TargetSource targetSource) {
 
 		if (this.beanFactory instanceof ConfigurableListableBeanFactory) {
 			AutoProxyUtils.exposeTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName, beanClass);
@@ -479,7 +479,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @return whether the given bean should be proxied with its target class
 	 * @see AutoProxyUtils#shouldProxyTargetClass
 	 */
-	protected boolean shouldProxyTargetClass(Class<?> beanClass, String beanName) {
+	protected boolean shouldProxyTargetClass(Class<?> beanClass, @Nullable String beanName) {
 		return (this.beanFactory instanceof ConfigurableListableBeanFactory &&
 				AutoProxyUtils.shouldProxyTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName));
 	}
@@ -506,7 +506,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * specific to this bean (may be empty, but not null)
 	 * @return the list of Advisors for the given bean
 	 */
-	protected Advisor[] buildAdvisors(String beanName, Object[] specificInterceptors) {
+	protected Advisor[] buildAdvisors(@Nullable String beanName, @Nullable Object[] specificInterceptors) {
 		// Handle prototypes correctly...
 		Advisor[] commonInterceptors = resolveInterceptorNames();
 
@@ -582,7 +582,8 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	 * @see #PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS
 	 */
 	@Nullable
-	protected abstract Object[] getAdvicesAndAdvisorsForBean(
+	protected abstract Object[] getAdvicesAndAdvisorsForBean(Class<?> beanClass,
-			Class<?> beanClass, String beanName, @Nullable TargetSource customTargetSource) throws BeansException;
+			@Nullable String beanName, @Nullable TargetSource customTargetSource)
+			throws BeansException;
 
 }

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AutoProxyUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -63,7 +63,7 @@ public abstract class AutoProxyUtils {
 	 * @param beanName the name of the bean
 	 * @return whether the given bean should be proxied with its target class
 	 */
-	public static boolean shouldProxyTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName) {
+	public static boolean shouldProxyTargetClass(ConfigurableListableBeanFactory beanFactory, @Nullable String beanName) {
 		if (beanName != null && beanFactory.containsBeanDefinition(beanName)) {
 			BeanDefinition bd = beanFactory.getBeanDefinition(beanName);
 			return Boolean.TRUE.equals(bd.getAttribute(PRESERVE_TARGET_CLASS_ATTRIBUTE));
@@ -81,7 +81,7 @@ public abstract class AutoProxyUtils {
 	 * @see org.springframework.beans.factory.BeanFactory#getType(String)
 	 */
 	@Nullable
-	public static Class<?> determineTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName) {
+	public static Class<?> determineTargetClass(ConfigurableListableBeanFactory beanFactory, @Nullable String beanName) {
 		if (beanName == null) {
 			return null;
 		}
@@ -102,7 +102,9 @@ public abstract class AutoProxyUtils {
 	 * @param targetClass the corresponding target class
 	 * @since 4.2.3
 	 */
-	static void exposeTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName, Class<?> targetClass) {
+	static void exposeTargetClass(ConfigurableListableBeanFactory beanFactory, @Nullable String beanName,
+			Class<?> targetClass) {
+
 		if (beanName != null && beanFactory.containsBeanDefinition(beanName)) {
 			beanFactory.getMergedBeanDefinition(beanName).setAttribute(ORIGINAL_TARGET_CLASS_ATTRIBUTE, targetClass);
 		}

spring-aop/src/main/java/org/springframework/aop/interceptor/AbstractMonitoringInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,8 @@ import java.lang.reflect.Method;
 
 import org.aopalliance.intercept.MethodInvocation;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Base class for monitoring interceptors, such as performance monitors.
  * Provides {@code prefix} and {@code suffix} properties
@@ -50,7 +52,7 @@ public abstract class AbstractMonitoringInterceptor extends AbstractTraceInterce
 	 * Set the text that will get appended to the trace data.
 	 * <p>Default is none.
 	 */
-	public void setPrefix(String prefix) {
+	public void setPrefix(@Nullable String prefix) {
 		this.prefix = (prefix != null ? prefix : "");
 	}
 
@@ -65,7 +67,7 @@ public abstract class AbstractMonitoringInterceptor extends AbstractTraceInterce
 	 * Set the text that will get prepended to the trace data.
 	 * <p>Default is none.
 	 */
-	public void setSuffix(String suffix) {
+	public void setSuffix(@Nullable String suffix) {
 		this.suffix = (suffix != null ? suffix : "");
 	}
 

spring-aop/src/main/java/org/springframework/aop/interceptor/AsyncExecutionAspectSupport.java

@@ -87,7 +87,7 @@ public abstract class AsyncExecutionAspectSupport implements BeanFactoryAware {
 	 * executor has been requested via a qualifier on the async method, in which case the
 	 * executor will be looked up at invocation time against the enclosing bean factory
 	 */
-	public AsyncExecutionAspectSupport(Executor defaultExecutor) {
+	public AsyncExecutionAspectSupport(@Nullable Executor defaultExecutor) {
 		this(defaultExecutor, new SimpleAsyncUncaughtExceptionHandler());
 	}
 
@@ -99,7 +99,7 @@ public abstract class AsyncExecutionAspectSupport implements BeanFactoryAware {
 	 * executor will be looked up at invocation time against the enclosing bean factory
 	 * @param exceptionHandler the {@link AsyncUncaughtExceptionHandler} to use
 	 */
-	public AsyncExecutionAspectSupport(Executor defaultExecutor, AsyncUncaughtExceptionHandler exceptionHandler) {
+	public AsyncExecutionAspectSupport(@Nullable Executor defaultExecutor, AsyncUncaughtExceptionHandler exceptionHandler) {
 		this.defaultExecutor = defaultExecutor;
 		this.exceptionHandler = exceptionHandler;
 	}
@@ -196,7 +196,7 @@ public abstract class AsyncExecutionAspectSupport implements BeanFactoryAware {
 	 * @see #getExecutorQualifier(Method)
 	 */
 	@Nullable
-	protected Executor findQualifiedExecutor(BeanFactory beanFactory, String qualifier) {
+	protected Executor findQualifiedExecutor(@Nullable BeanFactory beanFactory, String qualifier) {
 		if (beanFactory == null) {
 			throw new IllegalStateException("BeanFactory must be set on " + getClass().getSimpleName() +
 					" to access qualified executor '" + qualifier + "'");
@@ -217,7 +217,7 @@ public abstract class AsyncExecutionAspectSupport implements BeanFactoryAware {
 	 * @see #DEFAULT_TASK_EXECUTOR_BEAN_NAME
 	 */
 	@Nullable
-	protected Executor getDefaultExecutor(BeanFactory beanFactory) {
+	protected Executor getDefaultExecutor(@Nullable BeanFactory beanFactory) {
 		if (beanFactory != null) {
 			try {
 				// Search for TaskExecutor bean... not plain Executor since that would

spring-aop/src/main/java/org/springframework/aop/interceptor/AsyncExecutionInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,6 +31,7 @@ import org.springframework.core.BridgeMethodResolver;
 import org.springframework.core.Ordered;
 import org.springframework.core.task.AsyncTaskExecutor;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -73,7 +74,7 @@ public class AsyncExecutionInterceptor extends AsyncExecutionAspectSupport imple
 	 * or {@link java.util.concurrent.ExecutorService}) to delegate to;
 	 * as of 4.2.6, a local executor for this interceptor will be built otherwise
 	 */
-	public AsyncExecutionInterceptor(Executor defaultExecutor) {
+	public AsyncExecutionInterceptor(@Nullable Executor defaultExecutor) {
 		super(defaultExecutor);
 	}
 
@@ -84,7 +85,7 @@ public class AsyncExecutionInterceptor extends AsyncExecutionAspectSupport imple
 	 * as of 4.2.6, a local executor for this interceptor will be built otherwise
 	 * @param exceptionHandler the {@link AsyncUncaughtExceptionHandler} to use
 	 */
-	public AsyncExecutionInterceptor(Executor defaultExecutor, AsyncUncaughtExceptionHandler exceptionHandler) {
+	public AsyncExecutionInterceptor(@Nullable Executor defaultExecutor, AsyncUncaughtExceptionHandler exceptionHandler) {
 		super(defaultExecutor, exceptionHandler);
 	}
 

spring-aop/src/main/java/org/springframework/aop/interceptor/CustomizableTraceInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -292,7 +292,7 @@ public class CustomizableTraceInterceptor extends AbstractTraceInterceptor {
 	 * at {@code TRACE} level. Sub-classes can override this method
 	 * to control which level the message is written at.
 	 */
-	protected void writeToLog(Log logger, String message, Throwable ex) {
+	protected void writeToLog(Log logger, String message, @Nullable Throwable ex) {
 		if (ex != null) {
 			logger.trace(message, ex);
 		}

spring-aop/src/main/java/org/springframework/aop/scope/ScopedProxyUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.lang.Nullable;
 
 /**
  * Utility class for creating a scoped proxy.
@@ -102,7 +103,7 @@ public abstract class ScopedProxyUtils {
 	 * bean within a scoped proxy.
 	 * @since 4.1.4
 	 */
-	public static boolean isScopedTarget(String beanName) {
+	public static boolean isScopedTarget(@Nullable String beanName) {
 		return (beanName != null && beanName.startsWith(TARGET_NAME_PREFIX));
 	}
 

spring-aop/src/main/java/org/springframework/aop/support/AbstractBeanFactoryPointcutAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -101,11 +101,13 @@ public abstract class AbstractBeanFactoryPointcutAdvisor extends AbstractPointcu
 	@Override
 	public Advice getAdvice() {
 		Advice advice = this.advice;
-		if (advice != null || this.adviceBeanName == null) {
+		if (advice != null) {
 			return advice;
 		}
 
+		Assert.state(this.adviceBeanName != null, "'adviceBeanName' must be specified");
 		Assert.state(this.beanFactory != null, "BeanFactory must be set to resolve 'adviceBeanName'");
+
 		if (this.beanFactory.isSingleton(this.adviceBeanName)) {
 			// Rely on singleton semantics provided by the factory.
 			advice = this.beanFactory.getBean(this.adviceBeanName, Advice.class);

spring-aop/src/main/java/org/springframework/aop/support/AopUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -127,7 +127,10 @@ public abstract class AopUtils {
 	 * @since 4.3
 	 * @see MethodIntrospector#selectInvocableMethod(Method, Class)
 	 */
-	public static Method selectInvocableMethod(Method method, Class<?> targetType) {
+	public static Method selectInvocableMethod(Method method, @Nullable Class<?> targetType) {
+		if (targetType == null) {
+			return method;
+		}
 		Method methodToUse = MethodIntrospector.selectInvocableMethod(method, targetType);
 		if (Modifier.isPrivate(methodToUse.getModifiers()) && !Modifier.isStatic(methodToUse.getModifiers()) &&
 				SpringProxy.class.isAssignableFrom(targetType)) {
@@ -143,7 +146,7 @@ public abstract class AopUtils {
 	 * Determine whether the given method is an "equals" method.
 	 * @see java.lang.Object#equals
 	 */
-	public static boolean isEqualsMethod(Method method) {
+	public static boolean isEqualsMethod(@Nullable Method method) {
 		return ReflectionUtils.isEqualsMethod(method);
 	}
 
@@ -151,7 +154,7 @@ public abstract class AopUtils {
 	 * Determine whether the given method is a "hashCode" method.
 	 * @see java.lang.Object#hashCode
 	 */
-	public static boolean isHashCodeMethod(Method method) {
+	public static boolean isHashCodeMethod(@Nullable Method method) {
 		return ReflectionUtils.isHashCodeMethod(method);
 	}
 
@@ -159,7 +162,7 @@ public abstract class AopUtils {
 	 * Determine whether the given method is a "toString" method.
 	 * @see java.lang.Object#toString()
 	 */
-	public static boolean isToStringMethod(Method method) {
+	public static boolean isToStringMethod(@Nullable Method method) {
 		return ReflectionUtils.isToStringMethod(method);
 	}
 
@@ -167,7 +170,7 @@ public abstract class AopUtils {
 	 * Determine whether the given method is a "finalize" method.
 	 * @see java.lang.Object#finalize()
 	 */
-	public static boolean isFinalizeMethod(Method method) {
+	public static boolean isFinalizeMethod(@Nullable Method method) {
 		return (method != null && method.getName().equals("finalize") &&
 				method.getParameterCount() == 0);
 	}
@@ -326,7 +329,7 @@ public abstract class AopUtils {
 	 * @throws org.springframework.aop.AopInvocationException in case of a reflection error
 	 */
 	@Nullable
-	public static Object invokeJoinpointUsingReflection(Object target, Method method, Object[] args)
+	public static Object invokeJoinpointUsingReflection(@Nullable Object target, Method method, Object[] args)
 			throws Throwable {
 
 		// Use reflection to invoke the method.

spring-aop/src/main/java/org/springframework/aop/support/DefaultBeanFactoryPointcutAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.aop.support;
 
 import org.springframework.aop.Pointcut;
+import org.springframework.lang.Nullable;
 
 /**
  * Concrete BeanFactory-based PointcutAdvisor that allows for any Advice
@@ -43,7 +44,7 @@ public class DefaultBeanFactoryPointcutAdvisor extends AbstractBeanFactoryPointc
 	 * <p>Default is {@code Pointcut.TRUE}.
 	 * @see #setAdviceBeanName
 	 */
-	public void setPointcut(Pointcut pointcut) {
+	public void setPointcut(@Nullable Pointcut pointcut) {
 		this.pointcut = (pointcut != null ? pointcut : Pointcut.TRUE);
 	}
 

spring-aop/src/main/java/org/springframework/aop/support/DefaultPointcutAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.io.Serializable;
 import org.aopalliance.aop.Advice;
 
 import org.springframework.aop.Pointcut;
+import org.springframework.lang.Nullable;
 
 /**
  * Convenient Pointcut-driven Advisor implementation.
@@ -73,7 +74,7 @@ public class DefaultPointcutAdvisor extends AbstractGenericPointcutAdvisor imple
 	 * <p>Default is {@code Pointcut.TRUE}.
 	 * @see #setAdvice
 	 */
-	public void setPointcut(Pointcut pointcut) {
+	public void setPointcut(@Nullable Pointcut pointcut) {
 		this.pointcut = (pointcut != null ? pointcut : Pointcut.TRUE);
 	}
 

spring-aop/src/main/java/org/springframework/aop/support/ExpressionPointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2006 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.aop.support;
 
 import org.springframework.aop.Pointcut;
+import org.springframework.lang.Nullable;
 
 /**
  * Interface to be implemented by pointcuts that use String expressions.
@@ -29,6 +30,7 @@ public interface ExpressionPointcut extends Pointcut {
 	/**
 	 * Return the String expression for this pointcut.
 	 */
+	@Nullable
 	String getExpression();
 
 }

spring-aop/src/main/java/org/springframework/aop/support/MethodMatchers.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -125,11 +125,11 @@ public abstract class MethodMatchers {
 					(matchesClass2(targetClass) && this.mm2.matches(method, targetClass));
 		}
 
-		protected boolean matchesClass1(Class<?> targetClass) {
+		protected boolean matchesClass1(@Nullable Class<?> targetClass) {
 			return true;
 		}
 
-		protected boolean matchesClass2(Class<?> targetClass) {
+		protected boolean matchesClass2(@Nullable Class<?> targetClass) {
 			return true;
 		}
 
@@ -183,13 +183,13 @@ public abstract class MethodMatchers {
 		}
 
 		@Override
-		protected boolean matchesClass1(Class<?> targetClass) {
+		protected boolean matchesClass1(@Nullable Class<?> targetClass) {
-			return this.cf1.matches(targetClass);
+			return (targetClass != null && this.cf1.matches(targetClass));
 		}
 
 		@Override
-		protected boolean matchesClass2(Class<?> targetClass) {
+		protected boolean matchesClass2(@Nullable Class<?> targetClass) {
-			return this.cf2.matches(targetClass);
+			return (targetClass != null && this.cf2.matches(targetClass));
 		}
 
 		@Override

spring-aop/src/main/java/org/springframework/aop/support/NameMatchMethodPointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,7 +56,7 @@ public class NameMatchMethodPointcut extends StaticMethodMatcherPointcut impleme
 	 * Matching will be the union of all these; if any match,
 	 * the pointcut matches.
 	 */
-	public void setMappedNames(String... mappedNames) {
+	public void setMappedNames(@Nullable String... mappedNames) {
 		this.mappedNames = new LinkedList<>();
 		if (mappedNames != null) {
 			this.mappedNames.addAll(Arrays.asList(mappedNames));

spring-aop/src/main/java/org/springframework/aop/support/RegexpMethodPointcutAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,6 @@ import java.io.Serializable;
 import org.aopalliance.aop.Advice;
 
 import org.springframework.aop.Pointcut;
-import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -133,7 +132,6 @@ public class RegexpMethodPointcutAdvisor extends AbstractGenericPointcutAdvisor
 	 * will be used.
 	 * @return the Pointcut instance (never {@code null})
 	 */
-	@Nullable
 	protected AbstractRegexpMethodPointcut createPointcut() {
 		return new JdkRegexpMethodPointcut();
 	}

spring-aop/src/main/java/org/springframework/aop/support/annotation/AnnotationMatchingPointcut.java

@@ -69,8 +69,8 @@ public class AnnotationMatchingPointcut implements Pointcut {
 	 * @param methodAnnotationType the annotation type to look for at the method level
 	 * (can be {@code null})
 	 */
-	public AnnotationMatchingPointcut(
+	public AnnotationMatchingPointcut(@Nullable Class<? extends Annotation> classAnnotationType,
-			@Nullable Class<? extends Annotation> classAnnotationType, @Nullable Class<? extends Annotation> methodAnnotationType) {
+			@Nullable Class<? extends Annotation> methodAnnotationType) {
 
 		this(classAnnotationType, methodAnnotationType, false);
 	}
@@ -87,8 +87,8 @@ public class AnnotationMatchingPointcut implements Pointcut {
 	 * @see AnnotationClassFilter#AnnotationClassFilter(Class, boolean)
 	 * @see AnnotationMethodMatcher#AnnotationMethodMatcher(Class, boolean)
 	 */
-	public AnnotationMatchingPointcut(Class<? extends Annotation> classAnnotationType,
+	public AnnotationMatchingPointcut(@Nullable Class<? extends Annotation> classAnnotationType,
-			Class<? extends Annotation> methodAnnotationType, boolean checkInherited) {
+			@Nullable Class<? extends Annotation> methodAnnotationType, boolean checkInherited) {
 
 		Assert.isTrue((classAnnotationType != null || methodAnnotationType != null),
 				"Either Class annotation type or Method annotation type needs to be specified (or both)");

spring-aop/src/main/java/org/springframework/aop/target/AbstractBeanFactoryBasedTargetSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.aop.TargetSource;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -129,9 +130,7 @@ public abstract class AbstractBeanFactoryBasedTargetSource implements TargetSour
 					logger.trace("Getting bean with name '" + this.targetBeanName + "' in order to determine type");
 				}
 				Object beanInstance = this.beanFactory.getBean(this.targetBeanName);
-				if (beanInstance != null) {
+				this.targetClass = beanInstance.getClass();
-					this.targetClass = beanInstance.getClass();
-				}
 			}
 		}
 		return this.targetClass;

spring-aspects/src/test/resources/org/springframework/cache/config/annotation-cache-aspectj.xml

@@ -22,7 +22,7 @@
 
 	<cache:annotation-driven mode="aspectj" key-generator="keyGenerator"/>
 
-	<bean id="keyGenerator" class="org.springframework.cache.config.SomeKeyGenerator" />
+	<bean id="keyGenerator" class="org.springframework.cache.config.SomeKeyGenerator"/>
 
 	<bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager">
 		<property name="caches">
@@ -40,7 +40,7 @@
 		</property>
 	</bean>
 
-	<bean id="customKeyGenerator" class="org.springframework.cache.config.SomeCustomKeyGenerator" />
+	<bean id="customKeyGenerator" class="org.springframework.cache.config.SomeCustomKeyGenerator"/>
 
 	<bean id="customCacheManager" class="org.springframework.cache.support.SimpleCacheManager">
 		<property name="caches">
@@ -55,6 +55,7 @@
 	<bean id="debugInterceptor" class="org.springframework.aop.interceptor.DebugInterceptor"/>
 
 	<bean id="service" class="org.springframework.cache.config.DefaultCacheableService"/>
+
 	<bean id="classService" class="org.springframework.cache.config.AnnotatedClassCacheableService"/>
 
 </beans>

spring-beans-groovy/src/main/java/org/springframework/beans/factory/groovy/GroovyBeanDefinitionReader.java

@@ -257,7 +257,7 @@ public class GroovyBeanDefinitionReader extends AbstractBeanDefinitionReader imp
 
 		int countBefore = getRegistry().getBeanDefinitionCount();
 		try {
-			GroovyShell shell = new GroovyShell(getResourceLoader().getClassLoader(), binding);
+			GroovyShell shell = new GroovyShell(getBeanClassLoader(), binding);
 			shell.evaluate(encodedResource.getReader(), "beans");
 		}
 		catch (Throwable ex) {

spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,10 +56,10 @@ import org.springframework.util.StringUtils;
  * as String arrays are converted in such a format if the array itself is not
  * assignable.
  *
- * @author Rod Johnson
  * @author Juergen Hoeller
- * @author Rob Harrop
  * @author Stephane Nicoll
+ * @author Rod Johnson
+ * @author Rob Harrop
  * @since 4.2
  * @see #registerCustomEditor
  * @see #setPropertyValues
@@ -189,7 +189,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	 * @param nestedPath the nested path of the object
 	 * @param rootObject the root object at the top of the path
 	 */
-	public void setWrappedInstance(Object object, String nestedPath, @Nullable Object rootObject) {
+	public void setWrappedInstance(Object object, @Nullable String nestedPath, @Nullable Object rootObject) {
 		this.wrappedObject = ObjectUtils.unwrapOptional(object);
 		Assert.notNull(this.wrappedObject, "Target object must not be null");
 		this.nestedPath = (nestedPath != null ? nestedPath : "");
@@ -199,11 +199,12 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	public final Object getWrappedInstance() {
+		Assert.state(this.wrappedObject != null, "No wrapped instance");
 		return this.wrappedObject;
 	}
 
 	public final Class<?> getWrappedClass() {
-		return (this.wrappedObject != null ? this.wrappedObject.getClass() : null);
+		return getWrappedInstance().getClass();
 	}
 
 	/**
@@ -217,6 +218,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	 * Return the root object at the top of the path of this accessor.
 	 * @see #getNestedPath
 	 */
+	@Nullable
 	public final Object getRootInstance() {
 		return this.rootObject;
 	}
@@ -226,11 +228,12 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	 * @see #getNestedPath
 	 */
 	public final Class<?> getRootClass() {
-		return (this.rootObject != null ? this.rootObject.getClass() : null);
+		Assert.state(this.wrappedObject != null, "No root object");
+		return this.rootObject.getClass();
 	}
 
 	@Override
-	public void setPropertyValue(String propertyName, Object value) throws BeansException {
+	public void setPropertyValue(String propertyName, @Nullable Object value) throws BeansException {
 		AbstractNestablePropertyAccessor nestedPa;
 		try {
 			nestedPa = getPropertyAccessorForPropertyPath(propertyName);
@@ -279,10 +282,14 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	@SuppressWarnings("unchecked")
 	private void processKeyedProperty(PropertyTokenHolder tokens, PropertyValue pv) {
 		Object propValue = getPropertyHoldingValue(tokens);
+		PropertyHandler ph = getLocalPropertyHandler(tokens.actualName);
+		if (ph == null) {
+			throw new InvalidPropertyException(
+					getRootClass(), this.nestedPath + tokens.actualName, "No property handler found");
+		}
 		String lastKey = tokens.keys[tokens.keys.length - 1];
 
 		if (propValue.getClass().isArray()) {
-			PropertyHandler ph = getLocalPropertyHandler(tokens.actualName);
 			Class<?> requiredType = propValue.getClass().getComponentType();
 			int arrayIndex = Integer.parseInt(lastKey);
 			Object oldValue = null;
@@ -309,7 +316,6 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 		}
 
 		else if (propValue instanceof List) {
-			PropertyHandler ph = getPropertyHandler(tokens.actualName);
 			Class<?> requiredType = ph.getCollectionType(tokens.keys.length);
 			List<Object> list = (List<Object>) propValue;
 			int index = Integer.parseInt(lastKey);
@@ -346,7 +352,6 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 		}
 
 		else if (propValue instanceof Map) {
-			PropertyHandler ph = getLocalPropertyHandler(tokens.actualName);
 			Class<?> mapKeyType = ph.getMapKeyType(tokens.keys.length);
 			Class<?> mapValueType = ph.getMapValueType(tokens.keys.length);
 			Map<Object, Object> map = (Map<Object, Object>) propValue;
@@ -449,7 +454,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 				}
 				pv.getOriginalPropertyValue().conversionNecessary = (valueToApply != originalValue);
 			}
-			ph.setValue(this.wrappedObject, valueToApply);
+			ph.setValue(valueToApply);
 		}
 		catch (TypeMismatchException ex) {
 			throw ex;
@@ -567,34 +572,29 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 		return false;
 	}
 
-	private Object convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue, Object newValue, Class<?> requiredType,
+	@Nullable
-			TypeDescriptor td) throws TypeMismatchException {
+	private Object convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue,
+			@Nullable Object newValue, @Nullable Class<?> requiredType, @Nullable TypeDescriptor td)
+			throws TypeMismatchException {
+
 		try {
 			return this.typeConverterDelegate.convertIfNecessary(propertyName, oldValue, newValue, requiredType, td);
 		}
-		catch (ConverterNotFoundException ex) {
+		catch (ConverterNotFoundException | IllegalStateException ex) {
-			PropertyChangeEvent pce =
-					new PropertyChangeEvent(this.rootObject, this.nestedPath + propertyName, oldValue, newValue);
-			throw new ConversionNotSupportedException(pce, td.getType(), ex);
-		}
-		catch (ConversionException ex) {
-			PropertyChangeEvent pce =
-					new PropertyChangeEvent(this.rootObject, this.nestedPath + propertyName, oldValue, newValue);
-			throw new TypeMismatchException(pce, requiredType, ex);
-		}
-		catch (IllegalStateException ex) {
 			PropertyChangeEvent pce =
 					new PropertyChangeEvent(this.rootObject, this.nestedPath + propertyName, oldValue, newValue);
 			throw new ConversionNotSupportedException(pce, requiredType, ex);
 		}
-		catch (IllegalArgumentException ex) {
+		catch (ConversionException | IllegalArgumentException ex) {
 			PropertyChangeEvent pce =
 					new PropertyChangeEvent(this.rootObject, this.nestedPath + propertyName, oldValue, newValue);
 			throw new TypeMismatchException(pce, requiredType, ex);
 		}
 	}
 
-	protected Object convertForProperty(String propertyName, @Nullable Object oldValue, Object newValue, TypeDescriptor td)
+	@Nullable
+	protected Object convertForProperty(
+			String propertyName, @Nullable Object oldValue, @Nullable Object newValue, TypeDescriptor td)
 			throws TypeMismatchException {
 
 		return convertIfNecessary(propertyName, oldValue, newValue, td.getType(), td);
@@ -608,6 +608,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	@SuppressWarnings("unchecked")
+	@Nullable
 	protected Object getPropertyValue(PropertyTokenHolder tokens) throws BeansException {
 		String propertyName = tokens.canonicalName;
 		String actualName = tokens.actualName;
@@ -724,10 +725,10 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	/**
-	 * Return a {@link PropertyHandler} for the specified local {@code propertyName}. Only
+	 * Return a {@link PropertyHandler} for the specified local {@code propertyName}.
-	 * used to reach a property available in the current context.
+	 * Only used to reach a property available in the current context.
 	 * @param propertyName the name of a local property
-	 * @return the handler for that property or {@code null} if it has not been found
+	 * @return the handler for that property, or {@code null} if it has not been found
 	 */
 	@Nullable
 	protected abstract PropertyHandler getLocalPropertyHandler(String propertyName);
@@ -760,7 +761,9 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 				Array.set(newArray, i, newValue(componentType, null, name));
 			}
 			setPropertyValue(name, newArray);
-			return getPropertyValue(name);
+			Object defaultValue = getPropertyValue(name);
+			Assert.state(defaultValue != null, "Default value must not be null");
+			return defaultValue;
 		}
 		else {
 			return array;
@@ -872,17 +875,18 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	private Object setDefaultValue(PropertyTokenHolder tokens) {
 		PropertyValue pv = createDefaultPropertyValue(tokens);
 		setPropertyValue(tokens, pv);
-		return getPropertyValue(tokens);
+		Object defaultValue = getPropertyValue(tokens);
+		Assert.state(defaultValue != null, "Default value must not be null");
+		return defaultValue;
 	}
 
 	private PropertyValue createDefaultPropertyValue(PropertyTokenHolder tokens) {
 		TypeDescriptor desc = getPropertyTypeDescriptor(tokens.canonicalName);
-		Class<?> type = desc.getType();
+		if (desc == null) {
-		if (type == null) {
 			throw new NullValueInNestedPathException(getRootClass(), this.nestedPath + tokens.canonicalName,
 					"Could not determine property type for auto-growing a default value");
 		}
-		Object defaultValue = newValue(type, desc, tokens.canonicalName);
+		Object defaultValue = newValue(desc.getType(), desc, tokens.canonicalName);
 		return new PropertyValue(tokens.canonicalName, defaultValue);
 	}
 
@@ -1005,24 +1009,28 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 
 		public abstract ResolvableType getResolvableType();
 
+		@Nullable
 		public Class<?> getMapKeyType(int nestingLevel) {
 			return getResolvableType().getNested(nestingLevel).asMap().resolveGeneric(0);
 		}
 
+		@Nullable
 		public Class<?> getMapValueType(int nestingLevel) {
 			return getResolvableType().getNested(nestingLevel).asMap().resolveGeneric(1);
 		}
 
+		@Nullable
 		public Class<?> getCollectionType(int nestingLevel) {
 			return getResolvableType().getNested(nestingLevel).asCollection().resolveGeneric();
 		}
 
+		@Nullable
 		public abstract TypeDescriptor nested(int level);
 
 		@Nullable
 		public abstract Object getValue() throws Exception;
 
-		public abstract void setValue(Object object, Object value) throws Exception;
+		public abstract void setValue(@Nullable Object value) throws Exception;
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/AbstractPropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Abstract implementation of the {@link PropertyAccessor} interface.
  * Provides base implementations of all convenience methods, with the
@@ -151,6 +153,6 @@ public abstract class AbstractPropertyAccessor extends TypeConverterSupport impl
 	 * accessor method failed or a type mismatch occurred
 	 */
 	@Override
-	public abstract void setPropertyValue(String propertyName, Object value) throws BeansException;
+	public abstract void setPropertyValue(String propertyName, @Nullable Object value) throws BeansException;
 
 }

spring-beans/src/main/java/org/springframework/beans/BeanInstantiationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,7 +53,7 @@ public class BeanInstantiationException extends FatalBeanException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public BeanInstantiationException(Class<?> beanClass, String msg, Throwable cause) {
+	public BeanInstantiationException(Class<?> beanClass, String msg, @Nullable Throwable cause) {
 		super("Failed to instantiate [" + beanClass.getName() + "]: " + msg, cause);
 		this.beanClass = beanClass;
 	}
@@ -65,7 +65,7 @@ public class BeanInstantiationException extends FatalBeanException {
 	 * @param cause the root cause
 	 * @since 4.3
 	 */
-	public BeanInstantiationException(Constructor<?> constructor, String msg, Throwable cause) {
+	public BeanInstantiationException(Constructor<?> constructor, String msg, @Nullable Throwable cause) {
 		super("Failed to instantiate [" + constructor.getDeclaringClass().getName() + "]: " + msg, cause);
 		this.beanClass = constructor.getDeclaringClass();
 		this.constructor = constructor;
@@ -79,7 +79,7 @@ public class BeanInstantiationException extends FatalBeanException {
 	 * @param cause the root cause
 	 * @since 4.3
 	 */
-	public BeanInstantiationException(Method constructingMethod, String msg, Throwable cause) {
+	public BeanInstantiationException(Method constructingMethod, String msg, @Nullable Throwable cause) {
 		super("Failed to instantiate [" + constructingMethod.getReturnType().getName() + "]: " + msg, cause);
 		this.beanClass = constructingMethod.getReturnType();
 		this.constructingMethod = constructingMethod;

spring-beans/src/main/java/org/springframework/beans/BeanMetadataAttribute.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 
 package org.springframework.beans;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
@@ -40,7 +41,7 @@ public class BeanMetadataAttribute implements BeanMetadataElement {
 	 * @param name the name of the attribute (never {@code null})
 	 * @param value the value of the attribute (possibly before type conversion)
 	 */
-	public BeanMetadataAttribute(String name, Object value) {
+	public BeanMetadataAttribute(String name, @Nullable Object value) {
 		Assert.notNull(name, "Name must not be null");
 		this.name = name;
 		this.value = value;
@@ -65,7 +66,7 @@ public class BeanMetadataAttribute implements BeanMetadataElement {
 	 * Set the configuration source {@code Object} for this metadata element.
 	 * <p>The exact type of the object will depend on the configuration mechanism used.
 	 */
-	public void setSource(Object source) {
+	public void setSource(@Nullable Object source) {
 		this.source = source;
 	}
 

spring-beans/src/main/java/org/springframework/beans/BeanMetadataAttributeAccessor.java

@@ -37,7 +37,7 @@ public class BeanMetadataAttributeAccessor extends AttributeAccessorSupport impl
 	 * Set the configuration source {@code Object} for this metadata element.
 	 * <p>The exact type of the object will depend on the configuration mechanism used.
 	 */
-	public void setSource(Object source) {
+	public void setSource(@Nullable Object source) {
 		this.source = source;
 	}
 

spring-beans/src/main/java/org/springframework/beans/BeanUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -426,7 +426,7 @@ public abstract class BeanUtils {
 	 * @return the corresponding editor, or {@code null} if none found
 	 */
 	@Nullable
-	public static PropertyEditor findEditorByConvention(Class<?> targetType) {
+	public static PropertyEditor findEditorByConvention(@Nullable Class<?> targetType) {
 		if (targetType == null || targetType.isArray() || unknownEditorTypes.contains(targetType)) {
 			return null;
 		}
@@ -476,7 +476,7 @@ public abstract class BeanUtils {
 	 * @param beanClasses the classes to check against
 	 * @return the property type, or {@code Object.class} as fallback
 	 */
-	public static Class<?> findPropertyType(String propertyName, Class<?>... beanClasses) {
+	public static Class<?> findPropertyType(String propertyName, @Nullable Class<?>... beanClasses) {
 		if (beanClasses != null) {
 			for (Class<?> beanClass : beanClasses) {
 				PropertyDescriptor pd = getPropertyDescriptor(beanClass, propertyName);
@@ -599,8 +599,8 @@ public abstract class BeanUtils {
 	 * @throws BeansException if the copying failed
 	 * @see BeanWrapper
 	 */
-	private static void copyProperties(Object source, Object target, @Nullable Class<?> editable, String... ignoreProperties)
+	private static void copyProperties(Object source, Object target, @Nullable Class<?> editable,
-			throws BeansException {
+			@Nullable String... ignoreProperties) throws BeansException {
 
 		Assert.notNull(source, "Source must not be null");
 		Assert.notNull(target, "Target must not be null");

spring-beans/src/main/java/org/springframework/beans/BeanWrapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,8 +18,6 @@ package org.springframework.beans;
 
 import java.beans.PropertyDescriptor;
 
-import org.springframework.lang.Nullable;
-
 /**
  * The central interface of Spring's low-level JavaBeans infrastructure.
  *
@@ -64,18 +62,13 @@ public interface BeanWrapper extends ConfigurablePropertyAccessor {
 	int getAutoGrowCollectionLimit();
 
 	/**
-	 * Return the bean instance wrapped by this object, if any.
+	 * Return the bean instance wrapped by this object.
-	 * @return the bean instance, or {@code null} if none set
 	 */
-	@Nullable
 	Object getWrappedInstance();
 
 	/**
-	 * Return the type of the wrapped JavaBean object.
+	 * Return the type of the wrapped bean instance.
-	 * @return the type of the wrapped bean instance,
-	 * or {@code null} if no wrapped object has been set
 	 */
-	@Nullable
 	Class<?> getWrappedClass();
 
 	/**

spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,7 +18,6 @@ package org.springframework.beans;
 
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.Method;
-import java.lang.reflect.Modifier;
 import java.security.AccessControlContext;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -29,7 +28,7 @@ import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.Property;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * Default {@link BeanWrapper} implementation that should be sufficient
@@ -148,7 +147,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	}
 
 	@Override
-	public void setWrappedInstance(Object object, String nestedPath, @Nullable Object rootObject) {
+	public void setWrappedInstance(Object object, @Nullable String nestedPath, @Nullable Object rootObject) {
 		super.setWrappedInstance(object, nestedPath, rootObject);
 		setIntrospectionClass(getWrappedClass());
 	}
@@ -169,7 +168,6 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	 * for the wrapped object.
 	 */
 	private CachedIntrospectionResults getCachedIntrospectionResults() {
-		Assert.state(getWrappedInstance() != null, "BeanWrapper does not hold a bean instance");
 		if (this.cachedIntrospectionResults == null) {
 			this.cachedIntrospectionResults = CachedIntrospectionResults.forClass(getWrappedClass());
 		}
@@ -203,6 +201,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	 * @return the new value, possibly the result of type conversion
 	 * @throws TypeMismatchException if type conversion failed
 	 */
+	@Nullable
 	public Object convertForProperty(Object value, String propertyName) throws TypeMismatchException {
 		CachedIntrospectionResults cachedIntrospectionResults = getCachedIntrospectionResults();
 		PropertyDescriptor pd = cachedIntrospectionResults.getPropertyDescriptor(propertyName);
@@ -289,73 +288,45 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 		@Override
 		public Object getValue() throws Exception {
 			final Method readMethod = this.pd.getReadMethod();
-			if (!Modifier.isPublic(readMethod.getDeclaringClass().getModifiers()) && !readMethod.isAccessible()) {
-				if (System.getSecurityManager() != null) {
-					AccessController.doPrivileged(new PrivilegedAction<Object>() {
-						@Override
-						public Object run() {
-							readMethod.setAccessible(true);
-							return null;
-						}
-					});
-				}
-				else {
-					readMethod.setAccessible(true);
-				}
-			}
 			if (System.getSecurityManager() != null) {
+				AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
+					ReflectionUtils.makeAccessible(readMethod);
+					return null;
+				});
 				try {
-					return AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
+					return AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () ->
-						@Override
+							readMethod.invoke(getWrappedInstance(), (Object[]) null), acc);
-						public Object run() throws Exception {
-							return readMethod.invoke(getWrappedInstance(), (Object[]) null);
-						}
-					}, acc);
 				}
 				catch (PrivilegedActionException pae) {
 					throw pae.getException();
 				}
 			}
 			else {
+				ReflectionUtils.makeAccessible(readMethod);
 				return readMethod.invoke(getWrappedInstance(), (Object[]) null);
 			}
 		}
 
 		@Override
-		public void setValue(final Object object, Object valueToApply) throws Exception {
+		public void setValue(final @Nullable Object value) throws Exception {
 			final Method writeMethod = (this.pd instanceof GenericTypeAwarePropertyDescriptor ?
 					((GenericTypeAwarePropertyDescriptor) this.pd).getWriteMethodForActualAccess() :
 					this.pd.getWriteMethod());
-			if (!Modifier.isPublic(writeMethod.getDeclaringClass().getModifiers()) && !writeMethod.isAccessible()) {
-				if (System.getSecurityManager() != null) {
-					AccessController.doPrivileged(new PrivilegedAction<Object>() {
-						@Override
-						public Object run() {
-							writeMethod.setAccessible(true);
-							return null;
-						}
-					});
-				}
-				else {
-					writeMethod.setAccessible(true);
-				}
-			}
-			final Object value = valueToApply;
 			if (System.getSecurityManager() != null) {
+				AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
+					ReflectionUtils.makeAccessible(writeMethod);
+					return null;
+				});
 				try {
-					AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
+					AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () ->
-						@Override
+							writeMethod.invoke(getWrappedInstance(), value), acc);
-						public Object run() throws Exception {
-							writeMethod.invoke(object, value);
-							return null;
-						}
-					}, acc);
 				}
 				catch (PrivilegedActionException ex) {
 					throw ex.getException();
 				}
 			}
 			else {
+				ReflectionUtils.makeAccessible(writeMethod);
 				writeMethod.invoke(getWrappedInstance(), value);
 			}
 		}

spring-beans/src/main/java/org/springframework/beans/BeansException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@
 package org.springframework.beans;
 
 import org.springframework.core.NestedRuntimeException;
-import org.springframework.util.ObjectUtils;
+import org.springframework.lang.Nullable;
 
 /**
  * Abstract superclass for all exceptions thrown in the beans package
@@ -46,27 +46,8 @@ public abstract class BeansException extends NestedRuntimeException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public BeansException(String msg, Throwable cause) {
+	public BeansException(@Nullable String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 	}
 
-
-	@Override
-	public boolean equals(Object other) {
-		if (this == other) {
-			return true;
-		}
-		if (!(other instanceof BeansException)) {
-			return false;
-		}
-		BeansException otherBe = (BeansException) other;
-		return (getMessage().equals(otherBe.getMessage()) &&
-				ObjectUtils.nullSafeEquals(getCause(), otherBe.getCause()));
-	}
-
-	@Override
-	public int hashCode() {
-		return getMessage().hashCode();
-	}
-
 }

spring-beans/src/main/java/org/springframework/beans/CachedIntrospectionResults.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,6 +35,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.core.SpringProperties;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.io.support.SpringFactoriesLoader;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ConcurrentReferenceHashMap;
 import org.springframework.util.StringUtils;
@@ -136,7 +137,7 @@ public class CachedIntrospectionResults {
 	 * be paired with a {@link #clearClassLoader} call at application shutdown.
 	 * @param classLoader the ClassLoader to accept
 	 */
-	public static void acceptClassLoader(ClassLoader classLoader) {
+	public static void acceptClassLoader(@Nullable ClassLoader classLoader) {
 		if (classLoader != null) {
 			acceptedClassLoaders.add(classLoader);
 		}
@@ -148,7 +149,7 @@ public class CachedIntrospectionResults {
 	 * removing the ClassLoader (and its children) from the acceptance list.
 	 * @param classLoader the ClassLoader to clear the cache for
 	 */
-	public static void clearClassLoader(ClassLoader classLoader) {
+	public static void clearClassLoader(@Nullable ClassLoader classLoader) {
 		for (Iterator<ClassLoader> it = acceptedClassLoaders.iterator(); it.hasNext();) {
 			ClassLoader registeredLoader = it.next();
 			if (isUnderneathClassLoader(registeredLoader, classLoader)) {
@@ -226,7 +227,7 @@ public class CachedIntrospectionResults {
 	 * @param candidate the candidate ClassLoader to check
 	 * @param parent the parent ClassLoader to check for
 	 */
-	private static boolean isUnderneathClassLoader(ClassLoader candidate, ClassLoader parent) {
+	private static boolean isUnderneathClassLoader(@Nullable ClassLoader candidate, @Nullable ClassLoader parent) {
 		if (candidate == parent) {
 			return true;
 		}
@@ -336,6 +337,7 @@ public class CachedIntrospectionResults {
 		return this.beanInfo.getBeanDescriptor().getBeanClass();
 	}
 
+	@Nullable
 	PropertyDescriptor getPropertyDescriptor(String name) {
 		PropertyDescriptor pd = this.propertyDescriptorCache.get(name);
 		if (pd == null && StringUtils.hasLength(name)) {
@@ -375,6 +377,7 @@ public class CachedIntrospectionResults {
 		return (existing != null ? existing : td);
 	}
 
+	@Nullable
 	TypeDescriptor getTypeDescriptor(PropertyDescriptor pd) {
 		return this.typeDescriptorCache.get(pd);
 	}

spring-beans/src/main/java/org/springframework/beans/ConfigurablePropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,7 +37,7 @@ public interface ConfigurablePropertyAccessor extends PropertyAccessor, Property
 	 * Specify a Spring 3.0 ConversionService to use for converting
 	 * property values, as an alternative to JavaBeans PropertyEditors.
 	 */
-	void setConversionService(ConversionService conversionService);
+	void setConversionService(@Nullable ConversionService conversionService);
 
 	/**
 	 * Return the associated ConversionService, if any.

spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -134,10 +134,10 @@ public class DirectFieldAccessor extends AbstractNestablePropertyAccessor {
 		}
 
 		@Override
-		public void setValue(Object object, Object value) throws Exception {
+		public void setValue(Object value) throws Exception {
 			try {
 				ReflectionUtils.makeAccessible(this.field);
-				this.field.set(object, value);
+				this.field.set(getWrappedInstance(), value);
 			}
 			catch (IllegalAccessException ex) {
 				throw new InvalidPropertyException(getWrappedClass(), this.field.getName(),

spring-beans/src/main/java/org/springframework/beans/FatalBeanException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
 
 package org.springframework.beans;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Thrown on an unrecoverable problem encountered in the
  * beans packages or sub-packages, e.g. bad class or field.
@@ -39,7 +41,7 @@ public class FatalBeanException extends BeansException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public FatalBeanException(String msg, Throwable cause) {
+	public FatalBeanException(String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 	}
 

spring-beans/src/main/java/org/springframework/beans/GenericTypeAwarePropertyDescriptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.core.BridgeMethodResolver;
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
@@ -57,18 +58,14 @@ final class GenericTypeAwarePropertyDescriptor extends PropertyDescriptor {
 
 
 	public GenericTypeAwarePropertyDescriptor(Class<?> beanClass, String propertyName,
-			Method readMethod, Method writeMethod, Class<?> propertyEditorClass)
+			@Nullable Method readMethod, @Nullable Method writeMethod, Class<?> propertyEditorClass)
 			throws IntrospectionException {
 
 		super(propertyName, null, null);
-
-		if (beanClass == null)  {
-			throw new IntrospectionException("Bean class must not be null");
-		}
 		this.beanClass = beanClass;
 
-		Method readMethodToUse = BridgeMethodResolver.findBridgedMethod(readMethod);
+		Method readMethodToUse = (readMethod != null ? BridgeMethodResolver.findBridgedMethod(readMethod) : null);
-		Method writeMethodToUse = BridgeMethodResolver.findBridgedMethod(writeMethod);
+		Method writeMethodToUse = (writeMethod != null ? BridgeMethodResolver.findBridgedMethod(writeMethod) : null);
 		if (writeMethodToUse == null && readMethodToUse != null) {
 			// Fallback: Original JavaBeans introspection might not have found matching setter
 			// method due to lack of bridge method resolution, in case of the getter using a

spring-beans/src/main/java/org/springframework/beans/InvalidPropertyException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
 
 package org.springframework.beans;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Exception thrown when referring to an invalid bean property.
  * Carries the offending bean class and property name.
@@ -48,7 +50,7 @@ public class InvalidPropertyException extends FatalBeanException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public InvalidPropertyException(Class<?> beanClass, String propertyName, String msg, Throwable cause) {
+	public InvalidPropertyException(Class<?> beanClass, String propertyName, String msg, @Nullable Throwable cause) {
 		super("Invalid property '" + propertyName + "' of bean class [" + beanClass.getName() + "]: " + msg, cause);
 		this.beanClass = beanClass;
 		this.propertyName = propertyName;

spring-beans/src/main/java/org/springframework/beans/MutablePropertyValues.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -62,7 +62,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * @param original the PropertyValues to copy
 	 * @see #addPropertyValues(PropertyValues)
 	 */
-	public MutablePropertyValues(PropertyValues original) {
+	public MutablePropertyValues(@Nullable PropertyValues original) {
 		// We can optimize this because it's all new:
 		// There is no replacement of existing property values.
 		if (original != null) {
@@ -82,7 +82,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * @param original Map with property values keyed by property name Strings
 	 * @see #addPropertyValues(Map)
 	 */
-	public MutablePropertyValues(Map<?, ?> original) {
+	public MutablePropertyValues(@Nullable Map<?, ?> original) {
 		// We can optimize this because it's all new:
 		// There is no replacement of existing property values.
 		if (original != null) {
@@ -103,7 +103,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * It is not intended for typical programmatic use.
 	 * @param propertyValueList List of PropertyValue objects
 	 */
-	public MutablePropertyValues(List<PropertyValue> propertyValueList) {
+	public MutablePropertyValues(@Nullable List<PropertyValue> propertyValueList) {
 		this.propertyValueList =
 				(propertyValueList != null ? propertyValueList : new ArrayList<>());
 	}
@@ -133,7 +133,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * @param other the PropertyValues to copy
 	 * @return this in order to allow for adding multiple property values in a chain
 	 */
-	public MutablePropertyValues addPropertyValues(PropertyValues other) {
+	public MutablePropertyValues addPropertyValues(@Nullable PropertyValues other) {
 		if (other != null) {
 			PropertyValue[] pvs = other.getPropertyValues();
 			for (PropertyValue pv : pvs) {
@@ -149,7 +149,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * which must be a String
 	 * @return this in order to allow for adding multiple property values in a chain
 	 */
-	public MutablePropertyValues addPropertyValues(Map<?, ?> other) {
+	public MutablePropertyValues addPropertyValues(@Nullable Map<?, ?> other) {
 		if (other != null) {
 			for (Map.Entry<?, ?> entry : other.entrySet()) {
 				addPropertyValue(new PropertyValue(entry.getKey().toString(), entry.getValue()));
@@ -197,7 +197,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	 * @param propertyValue value of the property
 	 * @return this in order to allow for adding multiple property values in a chain
 	 */
-	public MutablePropertyValues add(String propertyName, Object propertyValue) {
+	public MutablePropertyValues add(String propertyName, @Nullable Object propertyValue) {
 		addPropertyValue(new PropertyValue(propertyName, propertyValue));
 		return this;
 	}
@@ -263,7 +263,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	/**
 	 * Get the raw property value, if any.
 	 * @param propertyName the name to search for
-	 * @return the raw property value, or {@code null}
+	 * @return the raw property value, or {@code null} if none found
 	 * @since 4.0
 	 * @see #getPropertyValue(String)
 	 * @see PropertyValue#getValue()

spring-beans/src/main/java/org/springframework/beans/PropertyAccessException.java

@@ -39,7 +39,7 @@ public abstract class PropertyAccessException extends BeansException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public PropertyAccessException(PropertyChangeEvent propertyChangeEvent, String msg, Throwable cause) {
+	public PropertyAccessException(PropertyChangeEvent propertyChangeEvent, String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 		this.propertyChangeEvent = propertyChangeEvent;
 	}
@@ -49,7 +49,7 @@ public abstract class PropertyAccessException extends BeansException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public PropertyAccessException(String msg, Throwable cause) {
+	public PropertyAccessException(String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 	}
 
@@ -67,6 +67,7 @@ public abstract class PropertyAccessException extends BeansException {
 	/**
 	 * Return the name of the affected property, if available.
 	 */
+	@Nullable
 	public String getPropertyName() {
 		return (this.propertyChangeEvent != null ? this.propertyChangeEvent.getPropertyName() : null);
 	}

spring-beans/src/main/java/org/springframework/beans/PropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -82,8 +82,6 @@ public interface PropertyAccessor {
 	 * (may be a nested path and/or an indexed/mapped property)
 	 * @return the property type for the particular property,
 	 * or {@code null} if not determinable
-	 * @throws InvalidPropertyException if there is no such property or
-	 * if the property isn't readable
 	 * @throws PropertyAccessException if the property was valid but the
 	 * accessor method failed
 	 */
@@ -97,8 +95,8 @@ public interface PropertyAccessor {
 	 * (may be a nested path and/or an indexed/mapped property)
 	 * @return the property type for the particular property,
 	 * or {@code null} if not determinable
-	 * @throws InvalidPropertyException if there is no such property or
+	 * @throws PropertyAccessException if the property was valid but the
-	 * if the property isn't readable
+	 * accessor method failed
 	 */
 	@Nullable
 	TypeDescriptor getPropertyTypeDescriptor(String propertyName) throws BeansException;
@@ -113,6 +111,7 @@ public interface PropertyAccessor {
 	 * @throws PropertyAccessException if the property was valid but the
 	 * accessor method failed
 	 */
+	@Nullable
 	Object getPropertyValue(String propertyName) throws BeansException;
 
 	/**
@@ -125,7 +124,7 @@ public interface PropertyAccessor {
 	 * @throws PropertyAccessException if the property was valid but the
 	 * accessor method failed or a type mismatch occurred
 	 */
-	void setPropertyValue(String propertyName, Object value) throws BeansException;
+	void setPropertyValue(String propertyName, @Nullable Object value) throws BeansException;
 
 	/**
 	 * Set the specified value as current property value.

spring-beans/src/main/java/org/springframework/beans/PropertyAccessorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
 
 package org.springframework.beans;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Utility methods for classes that perform bean property access
  * according to the {@link PropertyAccessor} interface.
@@ -42,7 +44,7 @@ public abstract class PropertyAccessorUtils {
 	 * @param propertyPath the property path to check
 	 * @return whether the path indicates an indexed or nested property
 	 */
-	public static boolean isNestedOrIndexedProperty(String propertyPath) {
+	public static boolean isNestedOrIndexedProperty(@Nullable String propertyPath) {
 		if (propertyPath == null) {
 			return false;
 		}
@@ -137,7 +139,7 @@ public abstract class PropertyAccessorUtils {
 	 * @param propertyName the bean property path
 	 * @return the canonical representation of the property path
 	 */
-	public static String canonicalPropertyName(String propertyName) {
+	public static String canonicalPropertyName(@Nullable String propertyName) {
 		if (propertyName == null) {
 			return "";
 		}
@@ -171,7 +173,8 @@ public abstract class PropertyAccessorUtils {
 	 * (as array of the same size)
 	 * @see #canonicalPropertyName(String)
 	 */
-	public static String[] canonicalPropertyNames(String[] propertyNames) {
+	@Nullable
+	public static String[] canonicalPropertyNames(@Nullable String[] propertyNames) {
 		if (propertyNames == null) {
 			return null;
 		}

spring-beans/src/main/java/org/springframework/beans/PropertyBatchUpdateException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -48,7 +48,7 @@ public class PropertyBatchUpdateException extends BeansException {
 	 * @param propertyAccessExceptions the List of PropertyAccessExceptions
 	 */
 	public PropertyBatchUpdateException(PropertyAccessException[] propertyAccessExceptions) {
-		super(null);
+		super(null, null);
 		Assert.notEmpty(propertyAccessExceptions, "At least 1 PropertyAccessException required");
 		this.propertyAccessExceptions = propertyAccessExceptions;
 	}
@@ -132,7 +132,7 @@ public class PropertyBatchUpdateException extends BeansException {
 	}
 
 	@Override
-	public boolean contains(Class<?> exType) {
+	public boolean contains(@Nullable Class<?> exType) {
 		if (exType == null) {
 			return false;
 		}

spring-beans/src/main/java/org/springframework/beans/PropertyDescriptorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.beans.PropertyDescriptor;
 import java.lang.reflect.Method;
 import java.util.Enumeration;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -60,7 +61,10 @@ class PropertyDescriptorUtils {
 	/**
 	 * See {@link java.beans.PropertyDescriptor#findPropertyType}.
 	 */
-	public static Class<?> findPropertyType(Method readMethod, Method writeMethod) throws IntrospectionException {
+	@Nullable
+	public static Class<?> findPropertyType(@Nullable Method readMethod, @Nullable Method writeMethod)
+			throws IntrospectionException {
+
 		Class<?> propertyType = null;
 
 		if (readMethod != null) {
@@ -103,8 +107,9 @@ class PropertyDescriptorUtils {
 	/**
 	 * See {@link java.beans.IndexedPropertyDescriptor#findIndexedPropertyType}.
 	 */
-	public static Class<?> findIndexedPropertyType(String name, Class<?> propertyType,
+	@Nullable
-			Method indexedReadMethod, Method indexedWriteMethod) throws IntrospectionException {
+	public static Class<?> findIndexedPropertyType(String name, @Nullable Class<?> propertyType,
+			@Nullable Method indexedReadMethod, @Nullable Method indexedWriteMethod) throws IntrospectionException {
 
 		Class<?> indexedPropertyType = null;
 

spring-beans/src/main/java/org/springframework/beans/PropertyEditorRegistrySupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -112,7 +112,7 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 	 * Specify a Spring 3.0 ConversionService to use for converting
 	 * property values, as an alternative to JavaBeans PropertyEditors.
 	 */
-	public void setConversionService(ConversionService conversionService) {
+	public void setConversionService(@Nullable ConversionService conversionService) {
 		this.conversionService = conversionService;
 	}
 
@@ -377,7 +377,7 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 	 * @return the custom editor, or {@code null} if none specific for this property
 	 */
 	@Nullable
-	private PropertyEditor getCustomEditor(String propertyName, Class<?> requiredType) {
+	private PropertyEditor getCustomEditor(String propertyName, @Nullable Class<?> requiredType) {
 		CustomEditorHolder holder = this.customEditorsForPath.get(propertyName);
 		return (holder != null ? holder.getPropertyEditor(requiredType) : null);
 	}
@@ -391,7 +391,7 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 	 * @see java.beans.PropertyEditor#getAsText()
 	 */
 	@Nullable
-	private PropertyEditor getCustomEditor(Class<?> requiredType) {
+	private PropertyEditor getCustomEditor(@Nullable Class<?> requiredType) {
 		if (requiredType == null || this.customEditors == null) {
 			return null;
 		}
@@ -521,7 +521,7 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 
 		private final Class<?> registeredType;
 
-		private CustomEditorHolder(PropertyEditor propertyEditor, Class<?> registeredType) {
+		private CustomEditorHolder(PropertyEditor propertyEditor, @Nullable Class<?> registeredType) {
 			this.propertyEditor = propertyEditor;
 			this.registeredType = registeredType;
 		}
@@ -530,11 +530,12 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 			return this.propertyEditor;
 		}
 
+		@Nullable
 		private Class<?> getRegisteredType() {
 			return this.registeredType;
 		}
 
-		private PropertyEditor getPropertyEditor(Class<?> requiredType) {
+		private PropertyEditor getPropertyEditor(@Nullable Class<?> requiredType) {
 			// Special case: If no required type specified, which usually only happens for
 			// Collection elements, or required type is not assignable to registered type,
 			// which usually only happens for generic properties of type Object -

spring-beans/src/main/java/org/springframework/beans/PropertyValue.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.beans;
 
 import java.io.Serializable;
 
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
@@ -63,7 +64,8 @@ public class PropertyValue extends BeanMetadataAttributeAccessor implements Seri
 	 * @param name the name of the property (never {@code null})
 	 * @param value the value of the property (possibly before type conversion)
 	 */
-	public PropertyValue(String name, Object value) {
+	public PropertyValue(String name, @Nullable Object value) {
+		Assert.notNull(name, "Name must not be null");
 		this.name = name;
 		this.value = value;
 	}
@@ -116,6 +118,7 @@ public class PropertyValue extends BeanMetadataAttributeAccessor implements Seri
 	 * It is the responsibility of the BeanWrapper implementation to
 	 * perform type conversion.
 	 */
+	@Nullable
 	public Object getValue() {
 		return this.value;
 	}

spring-beans/src/main/java/org/springframework/beans/PropertyValues.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,7 +37,7 @@ public interface PropertyValues {
 	/**
 	 * Return the property value with the given name, if any.
 	 * @param propertyName the name to search for
-	 * @return the property value, or {@code null}
+	 * @return the property value, or {@code null} if none
 	 */
 	@Nullable
 	PropertyValue getPropertyValue(String propertyName);

spring-beans/src/main/java/org/springframework/beans/TypeConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -50,7 +50,8 @@ public interface TypeConverter {
 	 * @see org.springframework.core.convert.ConversionService
 	 * @see org.springframework.core.convert.converter.Converter
 	 */
-	<T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType) throws TypeMismatchException;
+	@Nullable
+	<T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType) throws TypeMismatchException;
 
 	/**
 	 * Convert the value to the required type (if necessary from a String).
@@ -68,8 +69,9 @@ public interface TypeConverter {
 	 * @see org.springframework.core.convert.ConversionService
 	 * @see org.springframework.core.convert.converter.Converter
 	 */
-	<T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType, @Nullable MethodParameter methodParam)
+	@Nullable
-			throws TypeMismatchException;
+	<T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType,
+			@Nullable MethodParameter methodParam) throws TypeMismatchException;
 
 	/**
 	 * Convert the value to the required type (if necessary from a String).
@@ -87,7 +89,8 @@ public interface TypeConverter {
 	 * @see org.springframework.core.convert.ConversionService
 	 * @see org.springframework.core.convert.converter.Converter
 	 */
-	<T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType, @Nullable Field field)
+	@Nullable
+	<T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType, @Nullable Field field)
 			throws TypeMismatchException;
 
 }

spring-beans/src/main/java/org/springframework/beans/TypeConverterDelegate.java

@@ -75,7 +75,7 @@ class TypeConverterDelegate {
 	 * @param propertyEditorRegistry the editor registry to use
 	 * @param targetObject the target object to work on (as context that can be passed to editors)
 	 */
-	public TypeConverterDelegate(PropertyEditorRegistrySupport propertyEditorRegistry, Object targetObject) {
+	public TypeConverterDelegate(PropertyEditorRegistrySupport propertyEditorRegistry, @Nullable Object targetObject) {
 		this.propertyEditorRegistry = propertyEditorRegistry;
 		this.targetObject = targetObject;
 	}
@@ -91,8 +91,9 @@ class TypeConverterDelegate {
 	 * @return the new value, possibly the result of type conversion
 	 * @throws IllegalArgumentException if type conversion failed
 	 */
-	public <T> T convertIfNecessary(Object newValue, @Nullable Class<T> requiredType, @Nullable MethodParameter methodParam)
+	@Nullable
-			throws IllegalArgumentException {
+	public <T> T convertIfNecessary(@Nullable Object newValue, @Nullable Class<T> requiredType,
+			@Nullable MethodParameter methodParam) throws IllegalArgumentException {
 
 		return convertIfNecessary(null, null, newValue, requiredType,
 				(methodParam != null ? new TypeDescriptor(methodParam) : TypeDescriptor.valueOf(requiredType)));
@@ -108,7 +109,8 @@ class TypeConverterDelegate {
 	 * @return the new value, possibly the result of type conversion
 	 * @throws IllegalArgumentException if type conversion failed
 	 */
-	public <T> T convertIfNecessary(Object newValue, @Nullable Class<T> requiredType, @Nullable Field field)
+	@Nullable
+	public <T> T convertIfNecessary(@Nullable Object newValue, @Nullable Class<T> requiredType, @Nullable Field field)
 			throws IllegalArgumentException {
 
 		return convertIfNecessary(null, null, newValue, requiredType,
@@ -125,9 +127,9 @@ class TypeConverterDelegate {
 	 * @return the new value, possibly the result of type conversion
 	 * @throws IllegalArgumentException if type conversion failed
 	 */
-	public <T> T convertIfNecessary(
+	@Nullable
-			String propertyName, @Nullable Object oldValue, Object newValue, @Nullable Class<T> requiredType)
+	public <T> T convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue,
-			throws IllegalArgumentException {
+			Object newValue, @Nullable Class<T> requiredType) throws IllegalArgumentException {
 
 		return convertIfNecessary(propertyName, oldValue, newValue, requiredType, TypeDescriptor.valueOf(requiredType));
 	}
@@ -145,8 +147,9 @@ class TypeConverterDelegate {
 	 * @throws IllegalArgumentException if type conversion failed
 	 */
 	@SuppressWarnings("unchecked")
-	public <T> T convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue, Object newValue,
+	@Nullable
-			@Nullable Class<T> requiredType, TypeDescriptor typeDescriptor) throws IllegalArgumentException {
+	public <T> T convertIfNecessary(@Nullable String propertyName, @Nullable Object oldValue, @Nullable Object newValue,
+			@Nullable Class<T> requiredType, @Nullable TypeDescriptor typeDescriptor) throws IllegalArgumentException {
 
 		// Custom editor for this type?
 		PropertyEditor editor = this.propertyEditorRegistry.findCustomEditor(requiredType, propertyName);
@@ -268,7 +271,7 @@ class TypeConverterDelegate {
 					// Original exception from former ConversionService call above...
 					throw conversionAttemptEx;
 				}
-				else if (conversionService != null) {
+				else if (conversionService != null && typeDescriptor != null) {
 					// ConversionService not tried before, probably custom editor found
 					// but editor couldn't produce the required type...
 					TypeDescriptor sourceTypeDesc = TypeDescriptor.forObject(newValue);
@@ -359,7 +362,7 @@ class TypeConverterDelegate {
 	 * @return the corresponding editor, or {@code null} if none
 	 */
 	@Nullable
-	private PropertyEditor findDefaultEditor(Class<?> requiredType) {
+	private PropertyEditor findDefaultEditor(@Nullable Class<?> requiredType) {
 		PropertyEditor editor = null;
 		if (requiredType != null) {
 			// No custom editor -> check BeanWrapperImpl's default editors.
@@ -383,7 +386,10 @@ class TypeConverterDelegate {
 	 * @return the new value, possibly the result of type conversion
 	 * @throws IllegalArgumentException if type conversion failed
 	 */
-	private Object doConvertValue(@Nullable Object oldValue, Object newValue, @Nullable Class<?> requiredType, PropertyEditor editor) {
+	@Nullable
+	private Object doConvertValue(@Nullable Object oldValue, @Nullable Object newValue,
+			@Nullable Class<?> requiredType, @Nullable PropertyEditor editor) {
+
 		Object convertedValue = newValue;
 
 		if (editor != null && !(convertedValue instanceof String)) {
@@ -459,7 +465,7 @@ class TypeConverterDelegate {
 		return editor.getValue();
 	}
 
-	private Object convertToTypedArray(Object input, String propertyName, Class<?> componentType) {
+	private Object convertToTypedArray(Object input, @Nullable String propertyName, Class<?> componentType) {
 		if (input instanceof Collection) {
 			// Convert Collection elements to array elements.
 			Collection<?> coll = (Collection<?>) input;
@@ -498,8 +504,8 @@ class TypeConverterDelegate {
 	}
 
 	@SuppressWarnings("unchecked")
-	private Collection<?> convertToTypedCollection(
+	private Collection<?> convertToTypedCollection(Collection<?> original, @Nullable String propertyName,
-			Collection<?> original, String propertyName, Class<?> requiredType, TypeDescriptor typeDescriptor) {
+			Class<?> requiredType, @Nullable TypeDescriptor typeDescriptor) {
 
 		if (!Collection.class.isAssignableFrom(requiredType)) {
 			return original;
@@ -515,7 +521,7 @@ class TypeConverterDelegate {
 		}
 
 		boolean originalAllowed = requiredType.isInstance(original);
-		TypeDescriptor elementType = typeDescriptor.getElementTypeDescriptor();
+		TypeDescriptor elementType = (typeDescriptor != null ? typeDescriptor.getElementTypeDescriptor() : null);
 		if (elementType == null && originalAllowed &&
 				!this.propertyEditorRegistry.hasCustomEditorForElement(null, propertyName)) {
 			return original;
@@ -524,13 +530,6 @@ class TypeConverterDelegate {
 		Iterator<?> it;
 		try {
 			it = original.iterator();
-			if (it == null) {
-				if (logger.isDebugEnabled()) {
-					logger.debug("Collection of type [" + original.getClass().getName() +
-							"] returned null Iterator - injecting original Collection as-is");
-				}
-				return original;
-			}
 		}
 		catch (Throwable ex) {
 			if (logger.isDebugEnabled()) {
@@ -580,8 +579,8 @@ class TypeConverterDelegate {
 	}
 
 	@SuppressWarnings("unchecked")
-	private Map<?, ?> convertToTypedMap(
+	private Map<?, ?> convertToTypedMap(Map<?, ?> original, @Nullable String propertyName,
-			Map<?, ?> original, String propertyName, Class<?> requiredType, TypeDescriptor typeDescriptor) {
+			Class<?> requiredType, @Nullable TypeDescriptor typeDescriptor) {
 
 		if (!Map.class.isAssignableFrom(requiredType)) {
 			return original;
@@ -597,8 +596,8 @@ class TypeConverterDelegate {
 		}
 
 		boolean originalAllowed = requiredType.isInstance(original);
-		TypeDescriptor keyType = typeDescriptor.getMapKeyTypeDescriptor();
+		TypeDescriptor keyType = (typeDescriptor != null ? typeDescriptor.getMapKeyTypeDescriptor() : null);
-		TypeDescriptor valueType = typeDescriptor.getMapValueTypeDescriptor();
+		TypeDescriptor valueType = (typeDescriptor != null ? typeDescriptor.getMapValueTypeDescriptor() : null);
 		if (keyType == null && valueType == null && originalAllowed &&
 				!this.propertyEditorRegistry.hasCustomEditorForElement(null, propertyName)) {
 			return original;
@@ -607,13 +606,6 @@ class TypeConverterDelegate {
 		Iterator<?> it;
 		try {
 			it = original.entrySet().iterator();
-			if (it == null) {
-				if (logger.isDebugEnabled()) {
-					logger.debug("Map of type [" + original.getClass().getName() +
-							"] returned null Iterator - injecting original Map as-is");
-				}
-				return original;
-			}
 		}
 		catch (Throwable ex) {
 			if (logger.isDebugEnabled()) {
@@ -665,13 +657,15 @@ class TypeConverterDelegate {
 		return (originalAllowed ? original : convertedCopy);
 	}
 
-	private String buildIndexedPropertyName(String propertyName, int index) {
+	@Nullable
+	private String buildIndexedPropertyName(@Nullable String propertyName, int index) {
 		return (propertyName != null ?
 				propertyName + PropertyAccessor.PROPERTY_KEY_PREFIX + index + PropertyAccessor.PROPERTY_KEY_SUFFIX :
 				null);
 	}
 
-	private String buildKeyedPropertyName(String propertyName, Object key) {
+	@Nullable
+	private String buildKeyedPropertyName(@Nullable String propertyName, Object key) {
 		return (propertyName != null ?
 				propertyName + PropertyAccessor.PROPERTY_KEY_PREFIX + key + PropertyAccessor.PROPERTY_KEY_SUFFIX :
 				null);

spring-beans/src/main/java/org/springframework/beans/TypeConverterSupport.java

@@ -37,26 +37,28 @@ public abstract class TypeConverterSupport extends PropertyEditorRegistrySupport
 
 
 	@Override
-	public <T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType) throws TypeMismatchException {
+	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType) throws TypeMismatchException {
 		return doConvert(value, requiredType, null, null);
 	}
 
 	@Override
-	public <T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType, @Nullable MethodParameter methodParam)
+	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType, @Nullable MethodParameter methodParam)
 			throws TypeMismatchException {
 
 		return doConvert(value, requiredType, methodParam, null);
 	}
 
 	@Override
-	public <T> T convertIfNecessary(Object value, @Nullable Class<T> requiredType, @Nullable Field field)
+	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType, @Nullable Field field)
 			throws TypeMismatchException {
 
 		return doConvert(value, requiredType, null, field);
 	}
 
-	private <T> T doConvert(Object value, Class<T> requiredType, @Nullable MethodParameter methodParam, @Nullable Field field)
+	@Nullable
-			throws TypeMismatchException {
+	private <T> T doConvert(@Nullable Object value,@Nullable Class<T> requiredType,
+			@Nullable MethodParameter methodParam, @Nullable Field field) throws TypeMismatchException {
+
 		try {
 			if (field != null) {
 				return this.typeConverterDelegate.convertIfNecessary(value, requiredType, field);
@@ -65,16 +67,10 @@ public abstract class TypeConverterSupport extends PropertyEditorRegistrySupport
 				return this.typeConverterDelegate.convertIfNecessary(value, requiredType, methodParam);
 			}
 		}
-		catch (ConverterNotFoundException ex) {
+		catch (ConverterNotFoundException | IllegalStateException ex) {
 			throw new ConversionNotSupportedException(value, requiredType, ex);
 		}
-		catch (ConversionException ex) {
+		catch (ConversionException | IllegalArgumentException ex) {
-			throw new TypeMismatchException(value, requiredType, ex);
-		}
-		catch (IllegalStateException ex) {
-			throw new ConversionNotSupportedException(value, requiredType, ex);
-		}
-		catch (IllegalArgumentException ex) {
 			throw new TypeMismatchException(value, requiredType, ex);
 		}
 	}

spring-beans/src/main/java/org/springframework/beans/TypeMismatchException.java

@@ -56,7 +56,9 @@ public class TypeMismatchException extends PropertyAccessException {
 	 * @param requiredType the required target type (or {@code null} if not known)
 	 * @param cause the root cause (may be {@code null})
 	 */
-	public TypeMismatchException(PropertyChangeEvent propertyChangeEvent, @Nullable Class<?> requiredType, @Nullable Throwable cause) {
+	public TypeMismatchException(PropertyChangeEvent propertyChangeEvent, @Nullable Class<?> requiredType,
+			@Nullable Throwable cause) {
+
 		super(propertyChangeEvent,
 				"Failed to convert property value of type '" +
 				ClassUtils.getDescriptiveType(propertyChangeEvent.getNewValue()) + "'" +

spring-beans/src/main/java/org/springframework/beans/annotation/AnnotationBeanUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,7 +45,7 @@ public abstract class AnnotationBeanUtils {
 	 * @param excludedProperties the names of excluded properties, if any
 	 * @see org.springframework.beans.BeanWrapper
 	 */
-	public static void copyPropertiesToBean(Annotation ann, Object bean, @Nullable String... excludedProperties) {
+	public static void copyPropertiesToBean(Annotation ann, Object bean, String... excludedProperties) {
 		copyPropertiesToBean(ann, bean, null, excludedProperties);
 	}
 
@@ -59,7 +59,9 @@ public abstract class AnnotationBeanUtils {
 	 * @param excludedProperties the names of excluded properties, if any
 	 * @see org.springframework.beans.BeanWrapper
 	 */
-	public static void copyPropertiesToBean(Annotation ann, Object bean, @Nullable StringValueResolver valueResolver, @Nullable String... excludedProperties) {
+	public static void copyPropertiesToBean(Annotation ann, Object bean, @Nullable StringValueResolver valueResolver,
+			String... excludedProperties) {
+
 		Set<String> excluded = new HashSet<>(Arrays.asList(excludedProperties));
 		Method[] annotationProperties = ann.annotationType().getDeclaredMethods();
 		BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(bean);

spring-beans/src/main/java/org/springframework/beans/factory/BeanClassLoaderAware.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,6 @@
 
 package org.springframework.beans.factory;
 
-import org.springframework.lang.Nullable;
-
 /**
  * Callback that allows a bean to be aware of the bean
  * {@link ClassLoader class loader}; that is, the class loader used by the
@@ -47,11 +45,8 @@ public interface BeanClassLoaderAware extends Aware {
 	 * {@link InitializingBean InitializingBean's}
 	 * {@link InitializingBean#afterPropertiesSet()}
 	 * method or a custom init-method.
-	 * @param classLoader the owning class loader; may be {@code null} in
+	 * @param classLoader the owning class loader
-	 * which case a default {@code ClassLoader} must be used, for example
-	 * the {@code ClassLoader} obtained via
-	 * {@link org.springframework.util.ClassUtils#getDefaultClassLoader()}
 	 */
-	void setBeanClassLoader(@Nullable ClassLoader classLoader);
+	void setBeanClassLoader(ClassLoader classLoader);
 
 }

spring-beans/src/main/java/org/springframework/beans/factory/BeanCreationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -64,7 +64,7 @@ public class BeanCreationException extends FatalBeanException {
 	 * @param msg the detail message
 	 */
 	public BeanCreationException(String beanName, String msg) {
-		super("Error creating bean" + (beanName != null ? " with name '" + beanName + "'" : "") + ": " + msg);
+		super("Error creating bean with name '" + beanName + "': " + msg);
 		this.beanName = beanName;
 	}
 
@@ -86,8 +86,8 @@ public class BeanCreationException extends FatalBeanException {
 	 * @param beanName the name of the bean requested
 	 * @param msg the detail message
 	 */
-	public BeanCreationException(String resourceDescription, String beanName, String msg) {
+	public BeanCreationException(@Nullable String resourceDescription, @Nullable String beanName, String msg) {
-		super("Error creating bean" + (beanName != null ? " with name '" + beanName + "'" : "") +
+		super("Error creating bean with name '" + beanName + "'" +
 				(resourceDescription != null ? " defined in " + resourceDescription : "") + ": " + msg);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;
@@ -101,20 +101,12 @@ public class BeanCreationException extends FatalBeanException {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public BeanCreationException(String resourceDescription, String beanName, String msg, Throwable cause) {
+	public BeanCreationException(@Nullable String resourceDescription, String beanName, String msg, Throwable cause) {
 		this(resourceDescription, beanName, msg);
 		initCause(cause);
 	}
 
 
-	/**
-	 * Return the name of the bean requested, if any.
-	 */
-	@Nullable
-	public String getBeanName() {
-		return this.beanName;
-	}
-
 	/**
 	 * Return the description of the resource that the bean
 	 * definition came from, if any.
@@ -124,6 +116,13 @@ public class BeanCreationException extends FatalBeanException {
 		return this.resourceDescription;
 	}
 
+	/**
+	 * Return the name of the bean requested, if any.
+	 */
+	public String getBeanName() {
+		return this.beanName;
+	}
+
 	/**
 	 * Add a related cause to this bean creation exception,
 	 * not being a direct cause of the failure but having occurred
@@ -189,7 +188,7 @@ public class BeanCreationException extends FatalBeanException {
 	}
 
 	@Override
-	public boolean contains(Class<?> exClass) {
+	public boolean contains(@Nullable Class<?> exClass) {
 		if (super.contains(exClass)) {
 			return true;
 		}

spring-beans/src/main/java/org/springframework/beans/factory/BeanDefinitionStoreException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -57,7 +57,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 * @param resourceDescription description of the resource that the bean definition came from
 	 * @param msg the detail message (used as exception message as-is)
 	 */
-	public BeanDefinitionStoreException(String resourceDescription, String msg) {
+	public BeanDefinitionStoreException(@Nullable String resourceDescription, String msg) {
 		super(msg);
 		this.resourceDescription = resourceDescription;
 	}
@@ -68,7 +68,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 * @param msg the detail message (used as exception message as-is)
 	 * @param cause the root cause (may be {@code null})
 	 */
-	public BeanDefinitionStoreException(String resourceDescription, String msg, @Nullable Throwable cause) {
+	public BeanDefinitionStoreException(@Nullable String resourceDescription, String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 		this.resourceDescription = resourceDescription;
 	}
@@ -80,7 +80,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 * @param msg the detail message (appended to an introductory message that indicates
 	 * the resource and the name of the bean)
 	 */
-	public BeanDefinitionStoreException(String resourceDescription, String beanName, String msg) {
+	public BeanDefinitionStoreException(@Nullable String resourceDescription, String beanName, String msg) {
 		this(resourceDescription, beanName, msg, null);
 	}
 
@@ -92,7 +92,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 * the resource and the name of the bean)
 	 * @param cause the root cause (may be {@code null})
 	 */
-	public BeanDefinitionStoreException(String resourceDescription, String beanName, String msg, @Nullable Throwable cause) {
+	public BeanDefinitionStoreException(@Nullable String resourceDescription, String beanName, String msg, @Nullable Throwable cause) {
 		super("Invalid bean definition with name '" + beanName + "' defined in " + resourceDescription + ": " + msg, cause);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;

spring-beans/src/main/java/org/springframework/beans/factory/BeanFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -159,6 +159,22 @@ public interface BeanFactory {
 	 */
 	<T> T getBean(String name, @Nullable Class<T> requiredType) throws BeansException;
 
+	/**
+	 * Return an instance, which may be shared or independent, of the specified bean.
+	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,
+	 * overriding the specified default arguments (if any) in the bean definition.
+	 * @param name the name of the bean to retrieve
+	 * @param args arguments to use when creating a bean instance using explicit arguments
+	 * (only applied when creating a new instance as opposed to retrieving an existing one)
+	 * @return an instance of the bean
+	 * @throws NoSuchBeanDefinitionException if there is no such bean definition
+	 * @throws BeanDefinitionStoreException if arguments have been given but
+	 * the affected bean isn't a prototype
+	 * @throws BeansException if the bean could not be created
+	 * @since 2.5
+	 */
+	Object getBean(String name, Object... args) throws BeansException;
+
 	/**
 	 * Return the bean instance that uniquely matches the given object type, if any.
 	 * <p>This method goes into {@link ListableBeanFactory} by-type lookup territory
@@ -176,22 +192,6 @@ public interface BeanFactory {
 	 */
 	<T> T getBean(Class<T> requiredType) throws BeansException;
 
-	/**
-	 * Return an instance, which may be shared or independent, of the specified bean.
-	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,
-	 * overriding the specified default arguments (if any) in the bean definition.
-	 * @param name the name of the bean to retrieve
-	 * @param args arguments to use when creating a bean instance using explicit arguments
-	 * (only applied when creating a new instance as opposed to retrieving an existing one)
-	 * @return an instance of the bean
-	 * @throws NoSuchBeanDefinitionException if there is no such bean definition
-	 * @throws BeanDefinitionStoreException if arguments have been given but
-	 * the affected bean isn't a prototype
-	 * @throws BeansException if the bean could not be created
-	 * @since 2.5
-	 */
-	Object getBean(String name, Object... args) throws BeansException;
-
 	/**
 	 * Return an instance, which may be shared or independent, of the specified bean.
 	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,
@@ -298,7 +298,7 @@ public interface BeanFactory {
 	 * @see #getBean
 	 * @see #getType
 	 */
-	boolean isTypeMatch(String name, Class<?> typeToMatch) throws NoSuchBeanDefinitionException;
+	boolean isTypeMatch(String name, @Nullable Class<?> typeToMatch) throws NoSuchBeanDefinitionException;
 
 	/**
 	 * Determine the type of the bean with the given name. More specifically,

spring-beans/src/main/java/org/springframework/beans/factory/BeanFactoryUtils.java

@@ -24,6 +24,7 @@ import java.util.Map;
 
 import org.springframework.beans.BeansException;
 import org.springframework.core.ResolvableType;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -57,7 +58,7 @@ public abstract class BeanFactoryUtils {
 	 * @return whether the given name is a factory dereference
 	 * @see BeanFactory#FACTORY_BEAN_PREFIX
 	 */
-	public static boolean isFactoryDereference(String name) {
+	public static boolean isFactoryDereference(@Nullable String name) {
 		return (name != null && name.startsWith(BeanFactory.FACTORY_BEAN_PREFIX));
 	}
 
@@ -86,7 +87,7 @@ public abstract class BeanFactoryUtils {
 	 * @see org.springframework.beans.factory.support.BeanDefinitionReaderUtils#generateBeanName
 	 * @see org.springframework.beans.factory.support.DefaultBeanNameGenerator
 	 */
-	public static boolean isGeneratedBeanName(String name) {
+	public static boolean isGeneratedBeanName(@Nullable String name) {
 		return (name != null && name.contains(GENERATED_BEAN_NAME_SEPARATOR));
 	}
 

spring-beans/src/main/java/org/springframework/beans/factory/CannotLoadBeanClassException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.beans.factory;
 
 import org.springframework.beans.FatalBeanException;
+import org.springframework.lang.Nullable;
 
 /**
  * Exception thrown when the BeanFactory cannot load the specified class
@@ -44,10 +45,10 @@ public class CannotLoadBeanClassException extends FatalBeanException {
 	 * @param cause the root cause
 	 */
 	public CannotLoadBeanClassException(
-			String resourceDescription, String beanName, String beanClassName, ClassNotFoundException cause) {
+			@Nullable String resourceDescription, String beanName, @Nullable String beanClassName, ClassNotFoundException cause) {
 
-		super("Cannot find class [" + beanClassName + "] for bean with name '" + beanName +
+		super("Cannot find class [" + String.valueOf(beanClassName) + "] for bean with name '" + beanName + "'" +
-				"' defined in " + resourceDescription, cause);
+				(resourceDescription != null ? " defined in " + resourceDescription : ""), cause);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;
 		this.beanClassName = beanClassName;
@@ -62,10 +63,11 @@ public class CannotLoadBeanClassException extends FatalBeanException {
 	 * @param cause the root cause
 	 */
 	public CannotLoadBeanClassException(
-			String resourceDescription, String beanName, String beanClassName, LinkageError cause) {
+			@Nullable String resourceDescription, String beanName, @Nullable String beanClassName, LinkageError cause) {
 
-		super("Error loading class [" + beanClassName + "] for bean with name '" + beanName +
+		super("Error loading class [" + String.valueOf(beanClassName) + "] for bean with name '" + beanName + "'" +
-				"' defined in " + resourceDescription + ": problem with class file or dependent class", cause);
+				(resourceDescription != null ? " defined in " + resourceDescription : "") +
+				": problem with class file or dependent class", cause);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;
 		this.beanClassName = beanClassName;

spring-beans/src/main/java/org/springframework/beans/factory/ListableBeanFactory.java

@@ -106,7 +106,7 @@ public interface ListableBeanFactory extends BeanFactory {
 	 * result will be the same as for {@code getBeanNamesForType(type, true, true)}.
 	 * <p>Bean names returned by this method should always return bean names <i>in the
 	 * order of definition</i> in the backend configuration, as far as possible.
-	 * @param type the class or interface to match, or {@code null} for all bean names
+	 * @param type the generically typed class or interface to match
 	 * @return the names of beans (or objects created by FactoryBeans) matching
 	 * the given object type (including subclasses), or an empty array if none
 	 * @since 4.2
@@ -114,7 +114,7 @@ public interface ListableBeanFactory extends BeanFactory {
 	 * @see FactoryBean#getObjectType
 	 * @see BeanFactoryUtils#beanNamesForTypeIncludingAncestors(ListableBeanFactory, ResolvableType)
 	 */
-	String[] getBeanNamesForType(@Nullable ResolvableType type);
+	String[] getBeanNamesForType(ResolvableType type);
 
 	/**
 	 * Return the names of beans matching the given type (including subclasses),
@@ -268,7 +268,7 @@ public interface ListableBeanFactory extends BeanFactory {
 	 * found on the given class itself.
 	 * @param beanName the name of the bean to look for annotations on
 	 * @param annotationType the annotation class to look for
-	 * @return the annotation of the given type if found, or {@code null}
+	 * @return the annotation of the given type if found, or {@code null} otherwise
 	 * @throws NoSuchBeanDefinitionException if there is no bean with the given name
 	 * @since 3.0
 	 */

spring-beans/src/main/java/org/springframework/beans/factory/ObjectFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.beans.factory;
 
 import org.springframework.beans.BeansException;
+import org.springframework.lang.Nullable;
 
 /**
  * Defines a factory which can return an Object instance
@@ -41,9 +42,10 @@ public interface ObjectFactory<T> {
 	/**
 	 * Return an instance (possibly shared or independent)
 	 * of the object managed by this factory.
-	 * @return an instance of the bean (should never be {@code null})
+	 * @return the resulting instance
 	 * @throws BeansException in case of creation errors
 	 */
+	@Nullable
 	T getObject() throws BeansException;
 
 }

spring-beans/src/main/java/org/springframework/beans/factory/ObjectProvider.java

@@ -40,6 +40,7 @@ public interface ObjectProvider<T> extends ObjectFactory<T> {
 	 * @throws BeansException in case of creation errors
 	 * @see #getObject()
 	 */
+	@Nullable
 	T getObject(Object... args) throws BeansException;
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -228,10 +228,8 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 
 	@Override
 	public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName) {
-		if (beanType != null) {
+		InjectionMetadata metadata = findAutowiringMetadata(beanName, beanType, null);
-			InjectionMetadata metadata = findAutowiringMetadata(beanName, beanType, null);
+		metadata.checkConfigMembers(beanDefinition);
-			metadata.checkConfigMembers(beanDefinition);
-		}
 	}
 
 	@Override
@@ -389,7 +387,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	}
 
 
-	private InjectionMetadata findAutowiringMetadata(String beanName, Class<?> clazz, PropertyValues pvs) {
+	private InjectionMetadata findAutowiringMetadata(String beanName, Class<?> clazz, @Nullable PropertyValues pvs) {
 		// Fall back to class name as cache key, for backwards compatibility with custom callers.
 		String cacheKey = (StringUtils.hasLength(beanName) ? beanName : clazz.getName());
 		// Quick check on the concurrent map first, with minimal locking.
@@ -512,7 +510,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	/**
 	 * Register the specified bean as dependent on the autowired beans.
 	 */
-	private void registerDependentBeans(String beanName, Set<String> autowiredBeanNames) {
+	private void registerDependentBeans(@Nullable String beanName, Set<String> autowiredBeanNames) {
 		if (beanName != null) {
 			for (String autowiredBeanName : autowiredBeanNames) {
 				if (this.beanFactory.containsBean(autowiredBeanName)) {
@@ -529,7 +527,8 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	/**
 	 * Resolve the specified cached method argument or field value.
 	 */
-	private Object resolvedCachedArgument(String beanName, Object cachedArgument) {
+	@Nullable
+	private Object resolvedCachedArgument(@Nullable String beanName, Object cachedArgument) {
 		if (cachedArgument instanceof DependencyDescriptor) {
 			DependencyDescriptor descriptor = (DependencyDescriptor) cachedArgument;
 			return this.beanFactory.resolveDependency(descriptor, beanName, null, null);
@@ -557,7 +556,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 		}
 
 		@Override
-		protected void inject(Object bean, String beanName, PropertyValues pvs) throws Throwable {
+		protected void inject(Object bean, @Nullable String beanName, @Nullable PropertyValues pvs) throws Throwable {
 			Field field = (Field) this.member;
 			Object value;
 			if (this.cached) {
@@ -615,13 +614,13 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 
 		private volatile Object[] cachedMethodArguments;
 
-		public AutowiredMethodElement(Method method, boolean required, PropertyDescriptor pd) {
+		public AutowiredMethodElement(Method method, boolean required, @Nullable PropertyDescriptor pd) {
 			super(method, pd);
 			this.required = required;
 		}
 
 		@Override
-		protected void inject(Object bean, String beanName, PropertyValues pvs) throws Throwable {
+		protected void inject(Object bean, @Nullable String beanName, @Nullable PropertyValues pvs) throws Throwable {
 			if (checkPropertySkipping(pvs)) {
 				return;
 			}
@@ -694,7 +693,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 		}
 
 		@Nullable
-		private Object[] resolveCachedArguments(String beanName) {
+		private Object[] resolveCachedArguments(@Nullable String beanName) {
 			if (this.cachedMethodArguments == null) {
 				return null;
 			}

spring-beans/src/main/java/org/springframework/beans/factory/annotation/BeanFactoryAnnotationUtils.java

@@ -31,6 +31,7 @@ import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.AutowireCandidateQualifier;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -120,7 +121,9 @@ public abstract class BeanFactoryAnnotationUtils {
 	 * qualifier value (through {@code <qualifier>} or {@code @Qualifier})
 	 * @since 5.0
 	 */
-	public static boolean isQualifierMatch(Predicate<String> qualifier, String beanName, BeanFactory beanFactory) {
+	public static boolean isQualifierMatch(Predicate<String> qualifier, String beanName,
+			@Nullable BeanFactory beanFactory) {
+
 		// Try quick bean name or alias match first...
 		if (qualifier.test(beanName)) {
 			return true;

spring-beans/src/main/java/org/springframework/beans/factory/annotation/InitDestroyAnnotationBeanPostProcessor.java

@@ -121,10 +121,8 @@ public class InitDestroyAnnotationBeanPostProcessor
 
 	@Override
 	public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName) {
-		if (beanType != null) {
+		LifecycleMetadata metadata = findLifecycleMetadata(beanType);
-			LifecycleMetadata metadata = findLifecycleMetadata(beanType);
+		metadata.checkConfigMembers(beanDefinition);
-			metadata.checkConfigMembers(beanDefinition);
-		}
 	}
 
 	@Override

spring-beans/src/main/java/org/springframework/beans/factory/annotation/InjectionMetadata.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -77,7 +77,7 @@ public class InjectionMetadata {
 		this.checkedElements = checkedElements;
 	}
 
-	public void inject(Object target, String beanName, PropertyValues pvs) throws Throwable {
+	public void inject(Object target, @Nullable String beanName, @Nullable PropertyValues pvs) throws Throwable {
 		Collection<InjectedElement> elementsToIterate =
 				(this.checkedElements != null ? this.checkedElements : this.injectedElements);
 		if (!elementsToIterate.isEmpty()) {
@@ -94,7 +94,7 @@ public class InjectionMetadata {
 	/**
 	 * @since 3.2.13
 	 */
-	public void clear(PropertyValues pvs) {
+	public void clear(@Nullable PropertyValues pvs) {
 		Collection<InjectedElement> elementsToIterate =
 				(this.checkedElements != null ? this.checkedElements : this.injectedElements);
 		if (!elementsToIterate.isEmpty()) {
@@ -105,7 +105,7 @@ public class InjectionMetadata {
 	}
 
 
-	public static boolean needsRefresh(InjectionMetadata metadata, Class<?> clazz) {
+	public static boolean needsRefresh(@Nullable InjectionMetadata metadata, Class<?> clazz) {
 		return (metadata == null || metadata.targetClass != clazz);
 	}
 
@@ -120,7 +120,7 @@ public class InjectionMetadata {
 
 		protected volatile Boolean skip;
 
-		protected InjectedElement(Member member, PropertyDescriptor pd) {
+		protected InjectedElement(Member member, @Nullable PropertyDescriptor pd) {
 			this.member = member;
 			this.isField = (member instanceof Field);
 			this.pd = pd;
@@ -163,7 +163,9 @@ public class InjectionMetadata {
 		/**
 		 * Either this or {@link #getResourceToInject} needs to be overridden.
 		 */
-		protected void inject(Object target, String requestingBeanName, PropertyValues pvs) throws Throwable {
+		protected void inject(Object target, @Nullable String requestingBeanName, @Nullable PropertyValues pvs)
+				throws Throwable {
+
 			if (this.isField) {
 				Field field = (Field) this.member;
 				ReflectionUtils.makeAccessible(field);
@@ -189,7 +191,7 @@ public class InjectionMetadata {
 		 * an explicit property value having been specified. Also marks the
 		 * affected property as processed for other processors to ignore it.
 		 */
-		protected boolean checkPropertySkipping(PropertyValues pvs) {
+		protected boolean checkPropertySkipping(@Nullable PropertyValues pvs) {
 			if (this.skip != null) {
 				return this.skip;
 			}
@@ -219,7 +221,7 @@ public class InjectionMetadata {
 		/**
 		 * @since 3.2.13
 		 */
-		protected void clearPropertySkipping(PropertyValues pvs) {
+		protected void clearPropertySkipping(@Nullable PropertyValues pvs) {
 			if (pvs == null) {
 				return;
 			}
@@ -234,7 +236,7 @@ public class InjectionMetadata {
 		 * Either this or {@link #inject} needs to be overridden.
 		 */
 		@Nullable
-		protected Object getResourceToInject(Object target, String requestingBeanName) {
+		protected Object getResourceToInject(Object target, @Nullable String requestingBeanName) {
 			return null;
 		}
 

spring-beans/src/main/java/org/springframework/beans/factory/annotation/QualifierAnnotationAutowireCandidateResolver.java

@@ -145,7 +145,7 @@ public class QualifierAnnotationAutowireCandidateResolver extends GenericTypeAwa
 	@Override
 	public boolean isAutowireCandidate(BeanDefinitionHolder bdHolder, DependencyDescriptor descriptor) {
 		boolean match = super.isAutowireCandidate(bdHolder, descriptor);
-		if (match && descriptor != null) {
+		if (match) {
 			match = checkQualifiers(bdHolder, descriptor.getAnnotations());
 			if (match) {
 				MethodParameter methodParam = descriptor.getMethodParameter();
@@ -298,11 +298,13 @@ public class QualifierAnnotationAutowireCandidateResolver extends GenericTypeAwa
 		return true;
 	}
 
+	@Nullable
 	protected Annotation getQualifiedElementAnnotation(RootBeanDefinition bd, Class<? extends Annotation> type) {
 		AnnotatedElement qualifiedElement = bd.getQualifiedElement();
 		return (qualifiedElement != null ? AnnotationUtils.getAnnotation(qualifiedElement, type) : null);
 	}
 
+	@Nullable
 	protected Annotation getFactoryMethodAnnotation(RootBeanDefinition bd, Class<? extends Annotation> type) {
 		Method resolvedFactoryMethod = bd.getResolvedFactoryMethod();
 		return (resolvedFactoryMethod != null ? AnnotationUtils.getAnnotation(resolvedFactoryMethod, type) : null);

spring-beans/src/main/java/org/springframework/beans/factory/annotation/RequiredAnnotationBeanPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,6 +39,7 @@ import org.springframework.core.Conventions;
 import org.springframework.core.Ordered;
 import org.springframework.core.PriorityOrdered;
 import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -170,7 +171,7 @@ public class RequiredAnnotationBeanPostProcessor extends InstantiationAwareBeanP
 	 * @param beanName the name of the bean to check against
 	 * @return {@code true} to skip the bean; {@code false} to process it
 	 */
-	protected boolean shouldSkip(ConfigurableListableBeanFactory beanFactory, String beanName) {
+	protected boolean shouldSkip(@Nullable ConfigurableListableBeanFactory beanFactory, String beanName) {
 		if (beanFactory == null || !beanFactory.containsBeanDefinition(beanName)) {
 			return false;
 		}

spring-beans/src/main/java/org/springframework/beans/factory/config/AbstractFactoryBean.java

@@ -91,7 +91,7 @@ public abstract class AbstractFactoryBean<T>
 	}
 
 	@Override
-	public void setBeanClassLoader(@Nullable ClassLoader classLoader) {
+	public void setBeanClassLoader(ClassLoader classLoader) {
 		this.beanClassLoader = classLoader;
 	}
 

spring-beans/src/main/java/org/springframework/beans/factory/config/AutowireCapableBeanFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -268,6 +268,7 @@ public interface AutowireCapableBeanFactory extends BeanFactory {
 	 * @return the bean instance to use, either the original or a wrapped one
 	 * @throws BeansException if the initialization failed
 	 */
+	@Nullable
 	Object initializeBean(Object existingBean, String beanName) throws BeansException;
 
 	/**
@@ -280,6 +281,7 @@ public interface AutowireCapableBeanFactory extends BeanFactory {
 	 * @throws BeansException if any post-processing failed
 	 * @see BeanPostProcessor#postProcessBeforeInitialization
 	 */
+	@Nullable
 	Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName)
 			throws BeansException;
 
@@ -293,6 +295,7 @@ public interface AutowireCapableBeanFactory extends BeanFactory {
 	 * @throws BeansException if any post-processing failed
 	 * @see BeanPostProcessor#postProcessAfterInitialization
 	 */
+	@Nullable
 	Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName)
 			throws BeansException;
 
@@ -356,7 +359,7 @@ public interface AutowireCapableBeanFactory extends BeanFactory {
 	 * @see DependencyDescriptor
 	 */
 	@Nullable
-	Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName,
+	Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName,
 			@Nullable Set<String> autowiredBeanNames, @Nullable TypeConverter typeConverter) throws BeansException;
 
 }

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -101,7 +101,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	 * @see #setFactoryBeanName
 	 * @see #setFactoryMethodName
 	 */
-	void setBeanClassName(String beanClassName);
+	void setBeanClassName(@Nullable String beanClassName);
 
 	/**
 	 * Return the current bean class name of this bean definition.
@@ -115,6 +115,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	 * @see #getFactoryBeanName()
 	 * @see #getFactoryMethodName()
 	 */
+	@Nullable
 	String getBeanClassName();
 
 	/**
@@ -122,11 +123,10 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	 * @see #SCOPE_SINGLETON
 	 * @see #SCOPE_PROTOTYPE
 	 */
-	void setScope(String scope);
+	void setScope(@Nullable String scope);
 
 	/**
-	 * Return the name of the current target scope for this bean,
+	 * Return the name of the current target scope for this bean.
-	 * or {@code null} if not known yet.
 	 */
 	@Nullable
 	String getScope();
@@ -153,6 +153,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	/**
 	 * Return the bean names that this bean depends on.
 	 */
+	@Nullable
 	String[] getDependsOn();
 
 	/**
@@ -186,7 +187,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	 * This the name of the bean to call the specified factory method on.
 	 * @see #setFactoryMethodName
 	 */
-	void setFactoryBeanName(String factoryBeanName);
+	void setFactoryBeanName(@Nullable String factoryBeanName);
 
 	/**
 	 * Return the factory bean name, if any.
@@ -202,7 +203,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	 * @see #setFactoryBeanName
 	 * @see #setBeanClassName
 	 */
-	void setFactoryMethodName(String factoryMethodName);
+	void setFactoryMethodName(@Nullable String factoryMethodName);
 
 	/**
 	 * Return a factory method, if any.
@@ -259,6 +260,7 @@ public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {
 	/**
 	 * Return a human-readable description of this bean definition.
 	 */
+	@Nullable
 	String getDescription();
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanDefinitionHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -120,7 +120,7 @@ public class BeanDefinitionHolder implements BeanMetadataElement {
 	 * Determine whether the given candidate name matches the bean name
 	 * or the aliases stored in this bean definition.
 	 */
-	public boolean matchesName(String candidateName) {
+	public boolean matchesName(@Nullable String candidateName) {
 		return (candidateName != null && (candidateName.equals(this.beanName) ||
 				candidateName.equals(BeanFactoryUtils.transformedBeanName(this.beanName)) ||
 				ObjectUtils.containsElement(this.aliases, candidateName)));

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanDefinitionVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import java.util.Set;
 
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.PropertyValue;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringValueResolver;
@@ -164,7 +165,8 @@ public class BeanDefinitionVisitor {
 	}
 
 	@SuppressWarnings("rawtypes")
-	protected Object resolveValue(Object value) {
+	@Nullable
+	protected Object resolveValue(@Nullable Object value) {
 		if (value instanceof BeanDefinition) {
 			visitBeanDefinition((BeanDefinition) value);
 		}
@@ -174,6 +176,9 @@ public class BeanDefinitionVisitor {
 		else if (value instanceof RuntimeBeanReference) {
 			RuntimeBeanReference ref = (RuntimeBeanReference) value;
 			String newBeanName = resolveStringValue(ref.getBeanName());
+			if (newBeanName == null) {
+				return null;
+			}
 			if (!newBeanName.equals(ref.getBeanName())) {
 				return new RuntimeBeanReference(newBeanName);
 			}
@@ -181,6 +186,9 @@ public class BeanDefinitionVisitor {
 		else if (value instanceof RuntimeBeanNameReference) {
 			RuntimeBeanNameReference ref = (RuntimeBeanNameReference) value;
 			String newBeanName = resolveStringValue(ref.getBeanName());
+			if (newBeanName == null) {
+				return null;
+			}
 			if (!newBeanName.equals(ref.getBeanName())) {
 				return new RuntimeBeanNameReference(newBeanName);
 			}
@@ -274,6 +282,7 @@ public class BeanDefinitionVisitor {
 	 * @param strVal the original String value
 	 * @return the resolved String value
 	 */
+	@Nullable
 	protected String resolveStringValue(String strVal) {
 		if (this.valueResolver == null) {
 			throw new IllegalStateException("No StringValueResolver specified - pass a resolver " +

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanExpressionResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@
 package org.springframework.beans.factory.config;
 
 import org.springframework.beans.BeansException;
+import org.springframework.lang.Nullable;
 
 /**
  * Strategy interface for resolving a value through evaluating it
@@ -40,6 +41,7 @@ public interface BeanExpressionResolver {
 	 * @return the resolved value (potentially the given value as-is)
 	 * @throws BeansException if evaluation failed
 	 */
-	Object evaluate(String value, BeanExpressionContext evalContext) throws BeansException;
+	@Nullable
+	Object evaluate(@Nullable String value, BeanExpressionContext evalContext) throws BeansException;
 
 }

spring-beans/src/main/java/org/springframework/beans/factory/config/ConfigurableBeanFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -134,12 +134,13 @@ public interface ConfigurableBeanFactory extends HierarchicalBeanFactory, Single
 	 * here, supporting "#{...}" expressions in a Unified EL compatible style.
 	 * @since 3.0
 	 */
-	void setBeanExpressionResolver(BeanExpressionResolver resolver);
+	void setBeanExpressionResolver(@Nullable BeanExpressionResolver resolver);
 
 	/**
 	 * Return the resolution strategy for expressions in bean definition values.
 	 * @since 3.0
 	 */
+	@Nullable
 	BeanExpressionResolver getBeanExpressionResolver();
 
 	/**
@@ -147,7 +148,7 @@ public interface ConfigurableBeanFactory extends HierarchicalBeanFactory, Single
 	 * property values, as an alternative to JavaBeans PropertyEditors.
 	 * @since 3.0
 	 */
-	void setConversionService(ConversionService conversionService);
+	void setConversionService(@Nullable ConversionService conversionService);
 
 	/**
 	 * Return the associated ConversionService, if any.

spring-beans/src/main/java/org/springframework/beans/factory/config/ConfigurableListableBeanFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -78,7 +78,7 @@ public interface ConfigurableListableBeanFactory
 	 * implementation of the {@link org.springframework.beans.factory.ObjectFactory}
 	 * interface, which allows for lazy resolution of the actual target value.
 	 */
-	void registerResolvableDependency(Class<?> dependencyType, Object autowiredValue);
+	void registerResolvableDependency(Class<?> dependencyType, @Nullable Object autowiredValue);
 
 	/**
 	 * Determine whether the specified bean qualifies as an autowire candidate,
@@ -106,7 +106,7 @@ public interface ConfigurableListableBeanFactory
 	 * @throws NoSuchBeanDefinitionException if there is no bean with the given name
 	 * defined in this factory
 	 */
-	BeanDefinition getBeanDefinition(@Nullable String beanName) throws NoSuchBeanDefinitionException;
+	BeanDefinition getBeanDefinition(String beanName) throws NoSuchBeanDefinitionException;
 
 	/**
 	 * Return a unified view over all bean names managed by this factory.

spring-beans/src/main/java/org/springframework/beans/factory/config/ConstructorArgumentValues.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -70,7 +70,7 @@ public class ConstructorArgumentValues {
 	 * to allow for merging and re-merging of argument value definitions. Distinct
 	 * ValueHolder instances carrying the same content are of course allowed.
 	 */
-	public void addArgumentValues(ConstructorArgumentValues other) {
+	public void addArgumentValues(@Nullable ConstructorArgumentValues other) {
 		if (other != null) {
 			for (Map.Entry<Integer, ValueHolder> entry : other.indexedArgumentValues.entrySet()) {
 				addOrMergeIndexedArgumentValue(entry.getKey(), entry.getValue().copy());
@@ -89,7 +89,7 @@ public class ConstructorArgumentValues {
 	 * @param index the index in the constructor argument list
 	 * @param value the argument value
 	 */
-	public void addIndexedArgumentValue(int index, Object value) {
+	public void addIndexedArgumentValue(int index, @Nullable Object value) {
 		addIndexedArgumentValue(index, new ValueHolder(value));
 	}
 
@@ -99,7 +99,7 @@ public class ConstructorArgumentValues {
 	 * @param value the argument value
 	 * @param type the type of the constructor argument
 	 */
-	public void addIndexedArgumentValue(int index, Object value, String type) {
+	public void addIndexedArgumentValue(int index, @Nullable Object value, String type) {
 		addIndexedArgumentValue(index, new ValueHolder(value, type));
 	}
 
@@ -453,7 +453,7 @@ public class ConstructorArgumentValues {
 		 * Create a new ValueHolder for the given value.
 		 * @param value the argument value
 		 */
-		public ValueHolder(Object value) {
+		public ValueHolder(@Nullable Object value) {
 			this.value = value;
 		}
 
@@ -462,7 +462,7 @@ public class ConstructorArgumentValues {
 		 * @param value the argument value
 		 * @param type the type of the constructor argument
 		 */
-		public ValueHolder(Object value, String type) {
+		public ValueHolder(@Nullable Object value, @Nullable String type) {
 			this.value = value;
 			this.type = type;
 		}
@@ -473,7 +473,7 @@ public class ConstructorArgumentValues {
 		 * @param type the type of the constructor argument
 		 * @param name the name of the constructor argument
 		 */
-		public ValueHolder(Object value, String type, String name) {
+		public ValueHolder(@Nullable Object value, @Nullable String type, @Nullable String name) {
 			this.value = value;
 			this.type = type;
 			this.name = name;
@@ -483,13 +483,14 @@ public class ConstructorArgumentValues {
 		 * Set the value for the constructor argument.
 		 * @see PropertyPlaceholderConfigurer
 		 */
-		public void setValue(Object value) {
+		public void setValue(@Nullable Object value) {
 			this.value = value;
 		}
 
 		/**
 		 * Return the value for the constructor argument.
 		 */
+		@Nullable
 		public Object getValue() {
 			return this.value;
 		}
@@ -497,13 +498,14 @@ public class ConstructorArgumentValues {
 		/**
 		 * Set the type of the constructor argument.
 		 */
-		public void setType(String type) {
+		public void setType(@Nullable String type) {
 			this.type = type;
 		}
 
 		/**
 		 * Return the type of the constructor argument.
 		 */
+		@Nullable
 		public String getType() {
 			return this.type;
 		}
@@ -511,13 +513,14 @@ public class ConstructorArgumentValues {
 		/**
 		 * Set the name of the constructor argument.
 		 */
-		public void setName(String name) {
+		public void setName(@Nullable String name) {
 			this.name = name;
 		}
 
 		/**
 		 * Return the name of the constructor argument.
 		 */
+		@Nullable
 		public String getName() {
 			return this.name;
 		}
@@ -526,11 +529,12 @@ public class ConstructorArgumentValues {
 		 * Set the configuration source {@code Object} for this metadata element.
 		 * <p>The exact type of the object will depend on the configuration mechanism used.
 		 */
-		public void setSource(Object source) {
+		public void setSource(@Nullable Object source) {
 			this.source = source;
 		}
 
 		@Override
+		@Nullable
 		public Object getSource() {
 			return this.source;
 		}

spring-beans/src/main/java/org/springframework/beans/factory/config/DependencyDescriptor.java

@@ -99,12 +99,9 @@ public class DependencyDescriptor extends InjectionPoint implements Serializable
 
 		this.declaringClass = methodParameter.getDeclaringClass();
 		if (this.methodParameter.getMethod() != null) {
-			this.methodName = methodParameter.getMethod().getName();
+			this.methodName = this.methodParameter.getMethod().getName();
-			this.parameterTypes = methodParameter.getMethod().getParameterTypes();
-		}
-		else {
-			this.parameterTypes = methodParameter.getConstructor().getParameterTypes();
 		}
+		this.parameterTypes = methodParameter.getExecutable().getParameterTypes();
 		this.parameterIndex = methodParameter.getParameterIndex();
 		this.containingClass = methodParameter.getContainingClass();
 		this.required = required;
@@ -334,6 +331,7 @@ public class DependencyDescriptor extends InjectionPoint implements Serializable
 	 * Determine the name of the wrapped parameter/field.
 	 * @return the declared name (never {@code null})
 	 */
+	@Nullable
 	public String getDependencyName() {
 		return (this.field != null ? this.field.getName() : this.methodParameter.getParameterName());
 	}

spring-beans/src/main/java/org/springframework/beans/factory/config/DeprecatedBeanWarner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,7 +44,6 @@ public class DeprecatedBeanWarner implements BeanFactoryPostProcessor {
 	 * <p>This can be specified to not log into the category of this warner class but rather
 	 * into a specific named category.
 	 * @see org.apache.commons.logging.LogFactory#getLog(String)
-	 * @see org.apache.log4j.Logger#getLogger(String)
 	 * @see java.util.logging.Logger#getLogger(String)
 	 */
 	public void setLoggerName(String loggerName) {
@@ -61,10 +60,13 @@ public class DeprecatedBeanWarner implements BeanFactoryPostProcessor {
 				if (beanFactory.isFactoryBean(beanName)) {
 					nameToLookup = BeanFactory.FACTORY_BEAN_PREFIX + beanName;
 				}
-				Class<?> beanType = ClassUtils.getUserClass(beanFactory.getType(nameToLookup));
+				Class<?> beanType = beanFactory.getType(nameToLookup);
-				if (beanType != null && beanType.isAnnotationPresent(Deprecated.class)) {
+				if (beanType != null) {
-					BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
+					Class<?> userClass = ClassUtils.getUserClass(beanType);
-					logDeprecatedBean(beanName, beanType, beanDefinition);
+					if (userClass.isAnnotationPresent(Deprecated.class)) {
+						BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
+						logDeprecatedBean(beanName, beanType, beanDefinition);
+					}
 				}
 			}
 		}