MethodParameter supports Java 8 Executable/Parameter and validates parameter indexes

Also, equals insists on the same class now, differentiating from SynthesizingMethodParameter.

Issue: SPR-14055
Issue: SPR-13456
Issue: SPR-14438

spring-beans/src/main/java/org/springframework/beans/factory/support/ConstructorResolver.java

@@ -18,7 +18,7 @@ package org.springframework.beans.factory.support;
 
 import java.beans.ConstructorProperties;
 import java.lang.reflect.Constructor;
-import java.lang.reflect.Member;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.security.AccessController;
@@ -506,7 +506,7 @@ class ConstructorResolver {
 					// and explicitly ignore overridden methods (with the same parameter signature).
 					else if (factoryMethodToUse != null && typeDiffWeight == minTypeDiffWeight &&
 							!mbd.isLenientConstructorResolution() &&
-							paramTypes.length == factoryMethodToUse.getParameterTypes().length &&
+							paramTypes.length == factoryMethodToUse.getParameterCount() &&
 							!Arrays.equals(paramTypes, factoryMethodToUse.getParameterTypes())) {
 						if (ambiguousFactoryMethods == null) {
 							ambiguousFactoryMethods = new LinkedHashSet<>();
@@ -662,7 +662,7 @@ class ConstructorResolver {
 	 */
 	private ArgumentsHolder createArgumentArray(
 			String beanName, RootBeanDefinition mbd, ConstructorArgumentValues resolvedValues,
-			BeanWrapper bw, Class<?>[] paramTypes, String[] paramNames, Object methodOrCtor,
+			BeanWrapper bw, Class<?>[] paramTypes, String[] paramNames, Executable executable,
 			boolean autowiring) throws UnsatisfiedDependencyException {
 
 		TypeConverter converter = (this.beanFactory.getCustomTypeConverter() != null ?
@@ -699,7 +699,7 @@ class ConstructorResolver {
 					ConstructorArgumentValues.ValueHolder sourceHolder =
 							(ConstructorArgumentValues.ValueHolder) valueHolder.getSource();
 					Object sourceValue = sourceHolder.getValue();
-					MethodParameter methodParam = MethodParameter.forMethodOrConstructor(methodOrCtor, paramIndex);
+					MethodParameter methodParam = MethodParameter.forExecutable(executable, paramIndex);
 					try {
 						convertedValue = converter.convertIfNecessary(originalValue, paramType, methodParam);
 						// TODO re-enable once race condition has been found (SPR-7423)
@@ -727,7 +727,7 @@ class ConstructorResolver {
 				args.rawArguments[paramIndex] = originalValue;
 			}
 			else {
-				MethodParameter methodParam = MethodParameter.forMethodOrConstructor(methodOrCtor, paramIndex);
+				MethodParameter methodParam = MethodParameter.forExecutable(executable, paramIndex);
 				// No explicit match found: we're either supposed to autowire or
 				// have to fail creating an argument array for the given constructor.
 				if (!autowiring) {
@@ -755,7 +755,7 @@ class ConstructorResolver {
 			this.beanFactory.registerDependentBean(autowiredBeanName, beanName);
 			if (this.beanFactory.logger.isDebugEnabled()) {
 				this.beanFactory.logger.debug("Autowiring by type from bean name '" + beanName +
-						"' via " + (methodOrCtor instanceof Constructor ? "constructor" : "factory method") +
+						"' via " + (executable instanceof Constructor ? "constructor" : "factory method") +
 						" to bean named '" + autowiredBeanName + "'");
 			}
 		}
@@ -767,10 +767,9 @@ class ConstructorResolver {
 	 * Resolve the prepared arguments stored in the given bean definition.
 	 */
 	private Object[] resolvePreparedArguments(
-			String beanName, RootBeanDefinition mbd, BeanWrapper bw, Member methodOrCtor, Object[] argsToResolve) {
+			String beanName, RootBeanDefinition mbd, BeanWrapper bw, Executable executable, Object[] argsToResolve) {
 
-		Class<?>[] paramTypes = (methodOrCtor instanceof Method ?
+		Class<?>[] paramTypes = executable.getParameterTypes();
-				((Method) methodOrCtor).getParameterTypes() : ((Constructor<?>) methodOrCtor).getParameterTypes());
 		TypeConverter converter = (this.beanFactory.getCustomTypeConverter() != null ?
 				this.beanFactory.getCustomTypeConverter() : bw);
 		BeanDefinitionValueResolver valueResolver =
@@ -778,8 +777,8 @@ class ConstructorResolver {
 		Object[] resolvedArgs = new Object[argsToResolve.length];
 		for (int argIndex = 0; argIndex < argsToResolve.length; argIndex++) {
 			Object argValue = argsToResolve[argIndex];
-			MethodParameter methodParam = MethodParameter.forMethodOrConstructor(methodOrCtor, argIndex);
+			MethodParameter methodParam = MethodParameter.forExecutable(executable, argIndex);
-			GenericTypeResolver.resolveParameterType(methodParam, methodOrCtor.getDeclaringClass());
+			GenericTypeResolver.resolveParameterType(methodParam, executable.getDeclaringClass());
 			if (argValue instanceof AutowiredArgumentMarker) {
 				argValue = resolveAutowiredArgument(methodParam, beanName, null, converter);
 			}

spring-core/src/main/java/org/springframework/core/MethodParameter.java

@@ -19,8 +19,10 @@ package org.springframework.core;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.HashMap;
@@ -54,6 +56,8 @@ public class MethodParameter {
 
 	private final int parameterIndex;
 
+	private volatile Parameter parameter;
+
 	private int nestingLevel = 1;
 
 	/** Map from Integer level to Integer type index */
@@ -98,7 +102,7 @@ public class MethodParameter {
 	public MethodParameter(Method method, int parameterIndex, int nestingLevel) {
 		Assert.notNull(method, "Method must not be null");
 		this.method = method;
-		this.parameterIndex = parameterIndex;
+		this.parameterIndex = validateIndex(method, parameterIndex);
 		this.nestingLevel = nestingLevel;
 		this.constructor = null;
 	}
@@ -123,7 +127,7 @@ public class MethodParameter {
 	public MethodParameter(Constructor<?> constructor, int parameterIndex, int nestingLevel) {
 		Assert.notNull(constructor, "Constructor must not be null");
 		this.constructor = constructor;
-		this.parameterIndex = parameterIndex;
+		this.parameterIndex = validateIndex(constructor, parameterIndex);
 		this.nestingLevel = nestingLevel;
 		this.method = null;
 	}
@@ -138,6 +142,7 @@ public class MethodParameter {
 		this.method = original.method;
 		this.constructor = original.constructor;
 		this.parameterIndex = original.parameterIndex;
+		this.parameter = original.parameter;
 		this.nestingLevel = original.nestingLevel;
 		this.typeIndexesPerLevel = original.typeIndexesPerLevel;
 		this.containingClass = original.containingClass;
@@ -179,15 +184,7 @@ public class MethodParameter {
 	 * @return the Method or Constructor as Member
 	 */
 	public Member getMember() {
-		// NOTE: no ternary expression to retain JDK <8 compatibility even when using
+		return getExecutable();
-		// the JDK 8 compiler (potentially selecting java.lang.reflect.Executable
-		// as common type, with that new base class not available on older JDKs)
-		if (this.method != null) {
-			return this.method;
-		}
-		else {
-			return this.constructor;
-		}
 	}
 
 	/**
@@ -197,15 +194,27 @@ public class MethodParameter {
 	 * @return the Method or Constructor as AnnotatedElement
 	 */
 	public AnnotatedElement getAnnotatedElement() {
-		// NOTE: no ternary expression to retain JDK <8 compatibility even when using
+		return getExecutable();
-		// the JDK 8 compiler (potentially selecting java.lang.reflect.Executable
+	}
-		// as common type, with that new base class not available on older JDKs)
+
-		if (this.method != null) {
+	/**
-			return this.method;
+	 * Return the wrapped executable.
-		}
+	 * @return the Method or Constructor as Executable
-		else {
+	 * @since 5.0
-			return this.constructor;
+	 */
+	public Executable getExecutable() {
+		return (this.method != null ? this.method : this.constructor);
+	}
+
+	/**
+	 * Return the {@link Parameter} descriptor for method/constructor parameter.
+	 * @since 5.0
+	 */
+	public Parameter getParameter() {
+		if (this.parameter == null) {
+			this.parameter = getExecutable().getParameters()[this.parameterIndex];
 		}
+		return this.parameter;
 	}
 
 	/**
@@ -570,11 +579,11 @@ public class MethodParameter {
 		if (this == other) {
 			return true;
 		}
-		if (!(other instanceof MethodParameter)) {
+		if (other == null || getClass() != other.getClass()) {
 			return false;
 		}
 		MethodParameter otherParam = (MethodParameter) other;
-		return (this.parameterIndex == otherParam.parameterIndex && getMember().equals(otherParam.getMember()));
+		return (this.parameterIndex == otherParam.parameterIndex && getExecutable().equals(otherParam.getExecutable()));
 	}
 
 	@Override
@@ -596,23 +605,73 @@ public class MethodParameter {
 
 	/**
 	 * Create a new MethodParameter for the given method or constructor.
-	 * <p>This is a convenience constructor for scenarios where a
+	 * <p>This is a convenience factory method for scenarios where a
 	 * Method or Constructor reference is treated in a generic fashion.
 	 * @param methodOrConstructor the Method or Constructor to specify a parameter for
 	 * @param parameterIndex the index of the parameter
 	 * @return the corresponding MethodParameter instance
+	 * @deprecated as of 5.0, in favor of {@link #forExecutable}
 	 */
+	@Deprecated
 	public static MethodParameter forMethodOrConstructor(Object methodOrConstructor, int parameterIndex) {
-		if (methodOrConstructor instanceof Method) {
+		if (!(methodOrConstructor instanceof Executable)) {
-			return new MethodParameter((Method) methodOrConstructor, parameterIndex);
-		}
-		else if (methodOrConstructor instanceof Constructor) {
-			return new MethodParameter((Constructor<?>) methodOrConstructor, parameterIndex);
-		}
-		else {
 			throw new IllegalArgumentException(
 					"Given object [" + methodOrConstructor + "] is neither a Method nor a Constructor");
 		}
+		return forExecutable((Executable) methodOrConstructor, parameterIndex);
+	}
+
+	/**
+	 * Create a new MethodParameter for the given method or constructor.
+	 * <p>This is a convenience factory method for scenarios where a
+	 * Method or Constructor reference is treated in a generic fashion.
+	 * @param executable the Method or Constructor to specify a parameter for
+	 * @param parameterIndex the index of the parameter
+	 * @return the corresponding MethodParameter instance
+	 * @since 5.0
+	 */
+	public static MethodParameter forExecutable(Executable executable, int parameterIndex) {
+		if (executable instanceof Method) {
+			return new MethodParameter((Method) executable, parameterIndex);
+		}
+		else if (executable instanceof Constructor) {
+			return new MethodParameter((Constructor<?>) executable, parameterIndex);
+		}
+		else {
+			throw new IllegalArgumentException("Not a Method/Constructor: " + executable);
+		}
+	}
+
+	/**
+	 * Create a new MethodParameter for the given parameter descriptor.
+	 * <p>This is a convenience factory method for scenarios where a
+	 * Java 8 {@link Parameter} descriptor is already available.
+	 * @param parameter the parameter descriptor
+	 * @return the corresponding MethodParameter instance
+	 * @since 5.0
+	 */
+	public static MethodParameter forParameter(Parameter parameter) {
+		return forExecutable(parameter.getDeclaringExecutable(), findParameterIndex(parameter));
+	}
+
+	protected static int findParameterIndex(Parameter parameter) {
+		Executable executable = parameter.getDeclaringExecutable();
+		Parameter[] allParams = executable.getParameters();
+		for (int i = 0; i < allParams.length; i++) {
+			if (parameter == allParams[i]) {
+				return i;
+			}
+		}
+		throw new IllegalArgumentException("Given parameter [" + parameter +
+				"] does not match any parameter in the declaring executable");
+	}
+
+	private static int validateIndex(Executable executable, int parameterIndex) {
+		int count = executable.getParameterCount();
+		if (parameterIndex >= count) {
+			throw new IllegalArgumentException("Parameter index needs to be between 0 and " + (count - 1));
+		}
+		return parameterIndex;
 	}
 
 }

spring-core/src/main/java/org/springframework/core/annotation/SynthesizingMethodParameter.java

@@ -18,7 +18,9 @@ package org.springframework.core.annotation;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
 
 import org.springframework.core.MethodParameter;
 
@@ -108,4 +110,38 @@ public class SynthesizingMethodParameter extends MethodParameter {
 		return new SynthesizingMethodParameter(this);
 	}
 
+
+	/**
+	 * Create a new SynthesizingMethodParameter for the given method or constructor.
+	 * <p>This is a convenience factory method for scenarios where a
+	 * Method or Constructor reference is treated in a generic fashion.
+	 * @param executable the Method or Constructor to specify a parameter for
+	 * @param parameterIndex the index of the parameter
+	 * @return the corresponding SynthesizingMethodParameter instance
+	 * @since 5.0
+	 */
+	public static SynthesizingMethodParameter forExecutable(Executable executable, int parameterIndex) {
+		if (executable instanceof Method) {
+			return new SynthesizingMethodParameter((Method) executable, parameterIndex);
+		}
+		else if (executable instanceof Constructor) {
+			return new SynthesizingMethodParameter((Constructor<?>) executable, parameterIndex);
+		}
+		else {
+			throw new IllegalArgumentException("Not a Method/Constructor: " + executable);
+		}
+	}
+
+	/**
+	 * Create a new SynthesizingMethodParameter for the given parameter descriptor.
+	 * <p>This is a convenience factory method for scenarios where a
+	 * Java 8 {@link Parameter} descriptor is already available.
+	 * @param parameter the parameter descriptor
+	 * @return the corresponding SynthesizingMethodParameter instance
+	 * @since 5.0
+	 */
+	public static SynthesizingMethodParameter forParameter(Parameter parameter) {
+		return forExecutable(parameter.getDeclaringExecutable(), findParameterIndex(parameter));
+	}
+
 }

spring-core/src/test/java/org/springframework/core/GenericTypeResolverTests.java

@@ -158,7 +158,7 @@ public class GenericTypeResolverTests {
 	@Test
 	public void getGenericsOnArrayFromParamCannotBeResolved() throws Exception {
 		// SPR-11044
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(
+		MethodParameter methodParameter = MethodParameter.forExecutable(
 				WithArrayBase.class.getDeclaredMethod("array", Object[].class), 0);
 		Class<?> resolved = GenericTypeResolver.resolveParameterType(methodParameter, WithArray.class);
 		assertThat(resolved, equalTo((Class<?>) Object[].class));

spring-core/src/test/java/org/springframework/core/MethodParameterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -25,9 +25,12 @@ import static org.junit.Assert.*;
 
 /**
  * @author Arjen Poutsma
+ * @author Juergen Hoeller
  */
 public class MethodParameterTests {
 
+	private Method method;
+
 	private MethodParameter stringParameter;
 
 	private MethodParameter longParameter;
@@ -37,12 +40,13 @@ public class MethodParameterTests {
 
 	@Before
 	public void setUp() throws NoSuchMethodException {
-		Method method = getClass().getMethod("method", String.class, Long.TYPE);
+		method = getClass().getMethod("method", String.class, Long.TYPE);
 		stringParameter = new MethodParameter(method, 0);
 		longParameter = new MethodParameter(method, 1);
 		intReturnType = new MethodParameter(method, -1);
 	}
 
+
 	@Test
 	public void testEquals() throws NoSuchMethodException {
 		assertEquals(stringParameter, stringParameter);
@@ -60,8 +64,8 @@ public class MethodParameterTests {
 		MethodParameter methodParameter = new MethodParameter(method, 0);
 		assertEquals(stringParameter, methodParameter);
 		assertEquals(methodParameter, stringParameter);
-		assertFalse(longParameter.equals(methodParameter));
+		assertNotEquals(longParameter, methodParameter);
-		assertFalse(methodParameter.equals(longParameter));
+		assertNotEquals(methodParameter, longParameter);
 	}
 
 	@Test
@@ -73,7 +77,25 @@ public class MethodParameterTests {
 		Method method = getClass().getMethod("method", String.class, Long.TYPE);
 		MethodParameter methodParameter = new MethodParameter(method, 0);
 		assertEquals(stringParameter.hashCode(), methodParameter.hashCode());
-		assertTrue(longParameter.hashCode() != methodParameter.hashCode());
+		assertNotEquals(longParameter.hashCode(), methodParameter.hashCode());
+	}
+
+	@Test
+	@SuppressWarnings("deprecation")
+	public void testFactoryMethods() {
+		assertEquals(stringParameter, MethodParameter.forMethodOrConstructor(method, 0));
+		assertEquals(longParameter, MethodParameter.forMethodOrConstructor(method, 1));
+
+		assertEquals(stringParameter, MethodParameter.forExecutable(method, 0));
+		assertEquals(longParameter, MethodParameter.forExecutable(method, 1));
+
+		assertEquals(stringParameter, MethodParameter.forParameter(method.getParameters()[0]));
+		assertEquals(longParameter, MethodParameter.forParameter(method.getParameters()[1]));
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testIndexValidation() {
+		new MethodParameter(method, 2);
 	}
 
 

spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.java

@@ -214,7 +214,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void forMethodParameter() throws Exception {
 		Method method = Methods.class.getMethod("charSequenceParameter", List.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
 		assertThat(type.getType(), equalTo(method.getGenericParameterTypes()[0]));
 	}
@@ -222,7 +222,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void forMethodParameterWithNesting() throws Exception {
 		Method method = Methods.class.getMethod("nested", Map.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		methodParameter.increaseNestingLevel();
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
 		assertThat(type.resolve(), equalTo((Class) Map.class));
@@ -233,7 +233,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void forMethodParameterWithNestingAndLevels() throws Exception {
 		Method method = Methods.class.getMethod("nested", Map.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		methodParameter.increaseNestingLevel();
 		methodParameter.setTypeIndexForCurrentLevel(0);
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
@@ -782,7 +782,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void resolveTypeVariableFromMethodParameterType() throws Exception {
 		Method method = Methods.class.getMethod("typedParameter", Object.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
 		assertThat(type.resolve(), nullValue());
 		assertThat(type.getType().toString(), equalTo("T"));
@@ -791,7 +791,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void resolveTypeVariableFromMethodParameterTypeWithImplementsClass() throws Exception {
 		Method method = Methods.class.getMethod("typedParameter", Object.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		methodParameter.setContainingClass(TypedMethods.class);
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter);
 		assertThat(type.resolve(), equalTo((Class) String.class));
@@ -801,7 +801,7 @@ public class ResolvableTypeTests {
 	@Test
 	public void resolveTypeVariableFromMethodParameterTypeWithImplementsType() throws Exception {
 		Method method = Methods.class.getMethod("typedParameter", Object.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		ResolvableType implementationType = ResolvableType.forClassWithGenerics(Methods.class, Integer.class);
 		ResolvableType type = ResolvableType.forMethodParameter(methodParameter, implementationType);
 		assertThat(type.resolve(), equalTo((Class) Integer.class));
@@ -893,7 +893,7 @@ public class ResolvableTypeTests {
 		Field basicField = Fields.class.getField("classType");
 		Field field = Fields.class.getField("charSequenceList");
 		Method method = Methods.class.getMethod("charSequenceParameter", List.class);
-		MethodParameter methodParameter = MethodParameter.forMethodOrConstructor(method, 0);
+		MethodParameter methodParameter = MethodParameter.forExecutable(method, 0);
 		assertThat(ResolvableType.forField(basicField).getSource(), equalTo((Object) basicField));
 		assertThat(ResolvableType.forField(field).getSource(), equalTo((Object) field));
 		assertThat(ResolvableType.forMethodParameter(methodParameter).getSource(), equalTo((Object) methodParameter));

spring-core/src/test/java/org/springframework/core/SerializableTypeWrapperTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -46,78 +46,78 @@ public class SerializableTypeWrapperTests {
 	public void forField() throws Exception {
 		Type type = SerializableTypeWrapper.forField(Fields.class.getField("parameterizedType"));
 		assertThat(type.toString(), equalTo("java.util.List<java.lang.String>"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void forMethodParameter() throws Exception {
 		Method method = Methods.class.getDeclaredMethod("method", Class.class, Object.class);
-		Type type = SerializableTypeWrapper.forMethodParameter(MethodParameter.forMethodOrConstructor(method, 0));
+		Type type = SerializableTypeWrapper.forMethodParameter(MethodParameter.forExecutable(method, 0));
 		assertThat(type.toString(), equalTo("java.lang.Class<T>"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void forConstructor() throws Exception {
 		Constructor<?> constructor = Constructors.class.getDeclaredConstructor(List.class);
-		Type type = SerializableTypeWrapper.forMethodParameter(MethodParameter.forMethodOrConstructor(constructor, 0));
+		Type type = SerializableTypeWrapper.forMethodParameter(MethodParameter.forExecutable(constructor, 0));
 		assertThat(type.toString(), equalTo("java.util.List<java.lang.String>"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void forGenericSuperClass() throws Exception {
 		Type type = SerializableTypeWrapper.forGenericSuperclass(ArrayList.class);
 		assertThat(type.toString(), equalTo("java.util.AbstractList<E>"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void forGenericInterfaces() throws Exception {
 		Type type = SerializableTypeWrapper.forGenericInterfaces(List.class)[0];
 		assertThat(type.toString(), equalTo("java.util.Collection<E>"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void forTypeParamters() throws Exception {
 		Type type = SerializableTypeWrapper.forTypeParameters(List.class)[0];
 		assertThat(type.toString(), equalTo("E"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void classType() throws Exception {
 		Type type = SerializableTypeWrapper.forField(Fields.class.getField("classType"));
 		assertThat(type.toString(), equalTo("class java.lang.String"));
-		assertSerialzable(type);
+		assertSerializable(type);
 	}
 
 	@Test
 	public void genericArrayType() throws Exception {
 		GenericArrayType type = (GenericArrayType) SerializableTypeWrapper.forField(Fields.class.getField("genericArrayType"));
 		assertThat(type.toString(), equalTo("java.util.List<java.lang.String>[]"));
-		assertSerialzable(type);
+		assertSerializable(type);
-		assertSerialzable(type.getGenericComponentType());
+		assertSerializable(type.getGenericComponentType());
 	}
 
 	@Test
 	public void parameterizedType() throws Exception {
 		ParameterizedType type = (ParameterizedType) SerializableTypeWrapper.forField(Fields.class.getField("parameterizedType"));
 		assertThat(type.toString(), equalTo("java.util.List<java.lang.String>"));
-		assertSerialzable(type);
+		assertSerializable(type);
-		assertSerialzable(type.getOwnerType());
+		assertSerializable(type.getOwnerType());
-		assertSerialzable(type.getRawType());
+		assertSerializable(type.getRawType());
-		assertSerialzable(type.getActualTypeArguments());
+		assertSerializable(type.getActualTypeArguments());
-		assertSerialzable(type.getActualTypeArguments()[0]);
+		assertSerializable(type.getActualTypeArguments()[0]);
 	}
 
 	@Test
 	public void typeVariableType() throws Exception {
 		TypeVariable<?> type = (TypeVariable<?>) SerializableTypeWrapper.forField(Fields.class.getField("typeVariableType"));
 		assertThat(type.toString(), equalTo("T"));
-		assertSerialzable(type);
+		assertSerializable(type);
-		assertSerialzable(type.getBounds());
+		assertSerializable(type.getBounds());
 	}
 
 	@Test
@@ -125,13 +125,13 @@ public class SerializableTypeWrapperTests {
 		ParameterizedType typeSource = (ParameterizedType) SerializableTypeWrapper.forField(Fields.class.getField("wildcardType"));
 		WildcardType type = (WildcardType) typeSource.getActualTypeArguments()[0];
 		assertThat(type.toString(), equalTo("? extends java.lang.CharSequence"));
-		assertSerialzable(type);
+		assertSerializable(type);
-		assertSerialzable(type.getLowerBounds());
+		assertSerializable(type.getLowerBounds());
-		assertSerialzable(type.getUpperBounds());
+		assertSerializable(type.getUpperBounds());
 	}
 
 
-	private void assertSerialzable(Object source) throws Exception {
+	private void assertSerializable(Object source) throws Exception {
 		ByteArrayOutputStream bos = new ByteArrayOutputStream();
 		ObjectOutputStream oos = new ObjectOutputStream(bos);
 		oos.writeObject(source);
@@ -152,19 +152,19 @@ public class SerializableTypeWrapperTests {
 		public T typeVariableType;
 
 		public List<? extends CharSequence> wildcardType;
-
 	}
 
-	static interface Methods {
+
+	interface Methods {
 
 		<T> List<T> method(Class<T> p1, T p2);
-
 	}
 
+
 	static class Constructors {
 
 		public Constructors(List<String> p) {
 		}
-
 	}
+
 }

spring-core/src/test/java/org/springframework/core/annotation/SynthesizingMethodParameterTests.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2002-2016 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.core.annotation;
+
+import java.lang.reflect.Method;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.core.MethodParameter;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ */
+public class SynthesizingMethodParameterTests {
+
+	private Method method;
+
+	private SynthesizingMethodParameter stringParameter;
+
+	private SynthesizingMethodParameter longParameter;
+
+	private SynthesizingMethodParameter intReturnType;
+
+
+	@Before
+	public void setUp() throws NoSuchMethodException {
+		method = getClass().getMethod("method", String.class, Long.TYPE);
+		stringParameter = new SynthesizingMethodParameter(method, 0);
+		longParameter = new SynthesizingMethodParameter(method, 1);
+		intReturnType = new SynthesizingMethodParameter(method, -1);
+	}
+
+
+	@Test
+	public void testEquals() throws NoSuchMethodException {
+		assertEquals(stringParameter, stringParameter);
+		assertEquals(longParameter, longParameter);
+		assertEquals(intReturnType, intReturnType);
+
+		assertFalse(stringParameter.equals(longParameter));
+		assertFalse(stringParameter.equals(intReturnType));
+		assertFalse(longParameter.equals(stringParameter));
+		assertFalse(longParameter.equals(intReturnType));
+		assertFalse(intReturnType.equals(stringParameter));
+		assertFalse(intReturnType.equals(longParameter));
+
+		Method method = getClass().getMethod("method", String.class, Long.TYPE);
+		MethodParameter methodParameter = new SynthesizingMethodParameter(method, 0);
+		assertEquals(stringParameter, methodParameter);
+		assertEquals(methodParameter, stringParameter);
+		assertNotEquals(longParameter, methodParameter);
+		assertNotEquals(methodParameter, longParameter);
+
+		methodParameter = new MethodParameter(method, 0);
+		assertNotEquals(stringParameter, methodParameter);
+		assertNotEquals(methodParameter, stringParameter);
+		assertNotEquals(longParameter, methodParameter);
+		assertNotEquals(methodParameter, longParameter);
+	}
+
+	@Test
+	public void testHashCode() throws NoSuchMethodException {
+		assertEquals(stringParameter.hashCode(), stringParameter.hashCode());
+		assertEquals(longParameter.hashCode(), longParameter.hashCode());
+		assertEquals(intReturnType.hashCode(), intReturnType.hashCode());
+
+		Method method = getClass().getMethod("method", String.class, Long.TYPE);
+		SynthesizingMethodParameter methodParameter = new SynthesizingMethodParameter(method, 0);
+		assertEquals(stringParameter.hashCode(), methodParameter.hashCode());
+		assertNotEquals(longParameter.hashCode(), methodParameter.hashCode());
+	}
+
+	@Test
+	public void testFactoryMethods() {
+		assertEquals(stringParameter, SynthesizingMethodParameter.forExecutable(method, 0));
+		assertEquals(longParameter, SynthesizingMethodParameter.forExecutable(method, 1));
+
+		assertEquals(stringParameter, SynthesizingMethodParameter.forParameter(method.getParameters()[0]));
+		assertEquals(longParameter, SynthesizingMethodParameter.forParameter(method.getParameters()[1]));
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testIndexValidation() {
+		new SynthesizingMethodParameter(method, 2);
+	}
+
+
+	public int method(String p1, long p2) {
+		return 42;
+	}
+
+}

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectionHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.expression.spel.support;
 
 import java.lang.reflect.Array;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Method;
 import java.util.List;
 
@@ -241,7 +242,7 @@ public class ReflectionHelper {
 	public static boolean convertAllArguments(TypeConverter converter, Object[] arguments, Method method)
 			throws SpelEvaluationException {
 
-		Integer varargsPosition = (method.isVarArgs() ? method.getParameterTypes().length - 1 : null);
+		Integer varargsPosition = (method.isVarArgs() ? method.getParameterCount() - 1 : null);
 		return convertArguments(converter, arguments, method, varargsPosition);
 	}
 
@@ -250,19 +251,19 @@ public class ReflectionHelper {
 	 * required parameter types. The arguments are converted 'in-place' in the input array.
 	 * @param converter the type converter to use for attempting conversions
 	 * @param arguments the actual arguments that need conversion
-	 * @param methodOrCtor the target Method or Constructor
+	 * @param executable the target Method or Constructor
 	 * @param varargsPosition the known position of the varargs argument, if any
 	 * ({@code null} if not varargs)
 	 * @return {@code true} if some kind of conversion occurred on an argument
 	 * @throws EvaluationException if a problem occurs during conversion
 	 */
-	static boolean convertArguments(TypeConverter converter, Object[] arguments, Object methodOrCtor,
+	static boolean convertArguments(TypeConverter converter, Object[] arguments, Executable executable,
 			Integer varargsPosition) throws EvaluationException {
 
 		boolean conversionOccurred = false;
 		if (varargsPosition == null) {
 			for (int i = 0; i < arguments.length; i++) {
-				TypeDescriptor targetType = new TypeDescriptor(MethodParameter.forMethodOrConstructor(methodOrCtor, i));
+				TypeDescriptor targetType = new TypeDescriptor(MethodParameter.forExecutable(executable, i));
 				Object argument = arguments[i];
 				arguments[i] = converter.convertValue(argument, TypeDescriptor.forObject(argument), targetType);
 				conversionOccurred |= (argument != arguments[i]);
@@ -271,12 +272,12 @@ public class ReflectionHelper {
 		else {
 			// Convert everything up to the varargs position
 			for (int i = 0; i < varargsPosition; i++) {
-				TypeDescriptor targetType = new TypeDescriptor(MethodParameter.forMethodOrConstructor(methodOrCtor, i));
+				TypeDescriptor targetType = new TypeDescriptor(MethodParameter.forExecutable(executable, i));
 				Object argument = arguments[i];
 				arguments[i] = converter.convertValue(argument, TypeDescriptor.forObject(argument), targetType);
 				conversionOccurred |= (argument != arguments[i]);
 			}
-			MethodParameter methodParam = MethodParameter.forMethodOrConstructor(methodOrCtor, varargsPosition);
+			MethodParameter methodParam = MethodParameter.forExecutable(executable, varargsPosition);
 			if (varargsPosition == arguments.length - 1) {
 				// If the target is varargs and there is just one more argument
 				// then convert it here