BeanFactory supports ObjectFactory as a dependency type for @Autowired and @Value (SPR-6079)

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@1850 50f2f4bb-b051-0410-bef5-90022cba6387

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

@@ -16,8 +16,12 @@
 
 package org.springframework.beans.factory.config;
 
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
+import java.lang.reflect.Type;
 
 import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.MethodParameter;
@@ -32,17 +36,27 @@ import org.springframework.util.Assert;
  * @author Juergen Hoeller
  * @since 2.5
  */
-public class DependencyDescriptor {
+public class DependencyDescriptor implements Serializable {
 
-	private MethodParameter methodParameter;
+	private transient MethodParameter methodParameter;
 
-	private Field field;
+	private transient Field field;
+
+	private Class declaringClass;
+
+	private String methodName;
+
+	private Class[] parameterTypes;
+
+	private int parameterIndex;
+
+	private String fieldName;
 
 	private final boolean required;
 
 	private final boolean eager;
 
-	private Annotation[] fieldAnnotations;
+	private transient Annotation[] fieldAnnotations;
 
 
 	/**
@@ -65,6 +79,15 @@ public class DependencyDescriptor {
 	public DependencyDescriptor(MethodParameter methodParameter, boolean required, boolean eager) {
 		Assert.notNull(methodParameter, "MethodParameter must not be null");
 		this.methodParameter = methodParameter;
+		this.declaringClass = methodParameter.getDeclaringClass();
+		if (this.methodParameter.getMethod() != null) {
+			this.methodName = methodParameter.getMethod().getName();
+			this.parameterTypes = methodParameter.getMethod().getParameterTypes();
+		}
+		else {
+			this.parameterTypes = methodParameter.getConstructor().getParameterTypes();
+		}
+		this.parameterIndex = methodParameter.getParameterIndex();
 		this.required = required;
 		this.eager = eager;
 	}
@@ -89,6 +112,8 @@ public class DependencyDescriptor {
 	public DependencyDescriptor(Field field, boolean required, boolean eager) {
 		Assert.notNull(field, "Field must not be null");
 		this.field = field;
+		this.declaringClass = field.getDeclaringClass();
+		this.fieldName = field.getName();
 		this.required = required;
 		this.eager = eager;
 	}
@@ -156,6 +181,14 @@ public class DependencyDescriptor {
 		return (this.field != null ? this.field.getType() : this.methodParameter.getParameterType());
 	}
 
+	/**
+	 * Determine the generic type of the wrapped parameter/field.
+	 * @return the generic type (never <code>null</code>)
+	 */
+	public Type getGenericDependencyType() {
+		return (this.field != null ? this.field.getGenericType() : this.methodParameter.getGenericParameterType());
+	}
+
 	/**
 	 * Determine the generic element type of the wrapped Collection parameter/field, if any.
 	 * @return the generic type, or <code>null</code> if none
@@ -201,4 +234,32 @@ public class DependencyDescriptor {
 		}
 	}
 
+
+	//---------------------------------------------------------------------
+	// Serialization support
+	//---------------------------------------------------------------------
+
+	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
+		// Rely on default serialization; just initialize state after deserialization.
+		ois.defaultReadObject();
+
+		// Restore reflective handles (which are unfortunately not serializable)
+		try {
+			if (this.fieldName != null) {
+				this.field = this.declaringClass.getDeclaredField(this.fieldName);
+			}
+			else if (this.methodName != null) {
+				this.methodParameter = new MethodParameter(
+						this.declaringClass.getDeclaredMethod(this.methodName, this.parameterTypes), this.parameterIndex);
+			}
+			else {
+				this.methodParameter = new MethodParameter(
+						this.declaringClass.getDeclaredConstructor(this.parameterTypes), this.parameterIndex);
+			}
+		}
+		catch (Throwable ex) {
+			throw new IllegalStateException("Could not find original class structure", ex);
+		}
+	}
+
 }

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -21,6 +21,8 @@ import java.io.Serializable;
 import java.lang.annotation.Annotation;
 import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 import java.util.ArrayList;
@@ -508,14 +510,13 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
 					if (isFactoryBean(beanName)) {
 						final FactoryBean factory = (FactoryBean) getBean(FACTORY_BEAN_PREFIX + beanName);
-						boolean isEagerInit = false;
+						boolean isEagerInit;
-						
 						if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
 							isEagerInit = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
 								public Boolean run() {
-									return Boolean.valueOf(((SmartFactoryBean) factory).isEagerInit());
+									return ((SmartFactoryBean) factory).isEagerInit();
 								}
-							}, getAccessControlContext()).booleanValue();
+							}, getAccessControlContext());
 						}
 						else {
 							isEagerInit = factory instanceof SmartFactoryBean && ((SmartFactoryBean) factory).isEagerInit(); 
@@ -634,14 +635,23 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 
 
 	//---------------------------------------------------------------------
-	// Implementation of superclass abstract methods
+	// Dependency resolution functionality
 	//---------------------------------------------------------------------
 
 	public Object resolveDependency(DependencyDescriptor descriptor, String beanName,
 			Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException  {
 
 		descriptor.initParameterNameDiscovery(getParameterNameDiscoverer());
-		Class<?> type = descriptor.getDependencyType();
+		if (ObjectFactory.class.equals(descriptor.getDependencyType())) {
+			return new DependencyObjectFactory(descriptor, beanName);
+		}
+		else {
+			return doResolveDependency(descriptor, descriptor.getDependencyType(), beanName, autowiredBeanNames, typeConverter);
+		}
+	}
+
+	protected Object doResolveDependency(DependencyDescriptor descriptor, Class<?> type, String beanName,
+			Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException  {
 
 		Object value = getAutowireCandidateResolver().getSuggestedValue(descriptor);
 		if (value != null) {
@@ -649,7 +659,8 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				String strVal = resolveEmbeddedValue((String) value);
 				value = evaluateBeanDefinitionString(strVal, getMergedBeanDefinition(beanName));
 			}
-			return typeConverter.convertIfNecessary(value, type);
+			TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
+			return converter.convertIfNecessary(value, type);
 		}
 
 		if (type.isArray()) {
@@ -907,4 +918,38 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 	}
 
+
+	/**
+	 * Serializable ObjectFactory for lazy resolution of a dependency.
+	 */
+	private class DependencyObjectFactory implements ObjectFactory, Serializable {
+
+		private final DependencyDescriptor descriptor;
+
+		private final String beanName;
+
+		private final Class type;
+
+		public DependencyObjectFactory(DependencyDescriptor descriptor, String beanName) {
+			this.descriptor = descriptor;
+			this.beanName = beanName;
+			this.type = determineObjectFactoryType();
+		}
+
+		private Class determineObjectFactoryType() {
+			Type type = this.descriptor.getGenericDependencyType();
+			if (type instanceof ParameterizedType) {
+				Type arg = ((ParameterizedType) type).getActualTypeArguments()[0];
+				if (arg instanceof Class) {
+					return (Class) arg;
+				}
+			}
+			return Object.class;
+		}
+
+		public Object getObject() throws BeansException {
+			return doResolveDependency(this.descriptor, this.type, this.beanName, null, null);
+		}
+	}
+
 }

org.springframework.beans/src/test/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessorTests.java

@@ -16,8 +16,7 @@
 
 package org.springframework.beans.factory.annotation;
 
-import static org.junit.Assert.*;
+import java.io.Serializable;
-
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -25,20 +24,24 @@ import java.lang.annotation.Target;
 import java.util.List;
 import java.util.Map;
 
+import static org.junit.Assert.*;
 import org.junit.Test;
-import org.springframework.beans.factory.BeanCreationException;
-import org.springframework.beans.factory.BeanFactory;
-import org.springframework.beans.factory.FactoryBean;
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
-import org.springframework.beans.factory.support.DefaultListableBeanFactory;
-import org.springframework.beans.factory.support.GenericBeanDefinition;
-import org.springframework.beans.factory.support.RootBeanDefinition;
-
 import test.beans.ITestBean;
 import test.beans.IndexedTestBean;
 import test.beans.NestedTestBean;
 import test.beans.TestBean;
 
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.AutowireCandidateQualifier;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.beans.factory.support.GenericBeanDefinition;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.util.SerializationTestUtils;
+
 /**
  * Unit tests for {@link AutowiredAnnotationBeanPostProcessor}.
  * 
@@ -553,6 +556,53 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 		bf.destroySingletons();
 	}
 
+	@Test
+	public void testObjectFactoryInjection() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ObjectFactoryInjectionBean.class));
+		bf.registerBeanDefinition("testBean", new RootBeanDefinition(TestBean.class));
+
+		ObjectFactoryInjectionBean bean = (ObjectFactoryInjectionBean) bf.getBean("annotatedBean");
+		assertSame(bf.getBean("testBean"), bean.getTestBean());
+		bf.destroySingletons();
+	}
+
+	@Test
+	public void testObjectFactoryQualifierInjection() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ObjectFactoryQualifierInjectionBean.class));
+		RootBeanDefinition bd = new RootBeanDefinition(TestBean.class);
+		bd.addQualifier(new AutowireCandidateQualifier(Qualifier.class, "testBean"));
+		bf.registerBeanDefinition("testBean", bd);
+
+		ObjectFactoryQualifierInjectionBean bean = (ObjectFactoryQualifierInjectionBean) bf.getBean("annotatedBean");
+		assertSame(bf.getBean("testBean"), bean.getTestBean());
+		bf.destroySingletons();
+	}
+
+	@Test
+	public void testObjectFactorySerialization() throws Exception {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ObjectFactoryInjectionBean.class));
+		bf.registerBeanDefinition("testBean", new RootBeanDefinition(TestBean.class));
+		bf.setSerializationId("test");
+
+		ObjectFactoryInjectionBean bean = (ObjectFactoryInjectionBean) bf.getBean("annotatedBean");
+		assertSame(bf.getBean("testBean"), bean.getTestBean());
+		bean = (ObjectFactoryInjectionBean) SerializationTestUtils.serializeAndDeserialize(bean);
+		assertSame(bf.getBean("testBean"), bean.getTestBean());
+		bf.destroySingletons();
+	}
+
 	@Test
 	public void testCustomAnnotationRequiredFieldResourceInjection() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
@@ -1218,6 +1268,29 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 	}
 
 
+	public static class ObjectFactoryInjectionBean implements Serializable {
+
+		@Autowired
+		private ObjectFactory<TestBean> testBeanFactory;
+
+		public TestBean getTestBean() {
+			return this.testBeanFactory.getObject();
+		}
+	}
+
+
+	public static class ObjectFactoryQualifierInjectionBean {
+
+		@Autowired
+		//@Qualifier("testBean")
+		private ObjectFactory<?> testBeanFactory;
+
+		public TestBean getTestBean() {
+			return (TestBean) this.testBeanFactory.getObject();
+		}
+	}
+
+
 	public static class CustomAnnotationRequiredFieldResourceInjectionBean {
 
 		@MyAutowired(optional = false)

org.springframework.context/src/test/java/org/springframework/context/expression/ApplicationContextExpressionTests.java

@@ -17,6 +17,7 @@
 package org.springframework.context.expression;
 
 import java.util.Properties;
+import java.io.Serializable;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -37,6 +38,7 @@ import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.annotation.AnnotationConfigUtils;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.util.StopWatch;
+import org.springframework.util.SerializationTestUtils;
 
 /**
  * @author Juergen Hoeller
@@ -47,7 +49,7 @@ public class ApplicationContextExpressionTests {
 	private static final Log factoryLog = LogFactory.getLog(DefaultListableBeanFactory.class);
 
 	@Test
-	public void genericApplicationContext() {
+	public void genericApplicationContext() throws Exception {
 		GenericApplicationContext ac = new GenericApplicationContext();
 		AnnotationConfigUtils.registerAnnotationConfigProcessors(ac);
 
@@ -139,8 +141,12 @@ public class ApplicationContextExpressionTests {
 			assertEquals("XXXmyNameYYY42ZZZ", tb3.name);
 			assertEquals(42, tb3.age);
 			assertEquals("123 UK", tb3.country);
+			assertEquals("123 UK", tb3.countryFactory.getObject());
 			assertSame(tb0, tb3.tb);
 
+			tb3 = (ValueTestBean) SerializationTestUtils.serializeAndDeserialize(tb3);
+			assertEquals("123 UK", tb3.countryFactory.getObject());
+
 			ConstructorValueTestBean tb4 = ac.getBean("tb4", ConstructorValueTestBean.class);
 			assertEquals("XXXmyNameYYY42ZZZ", tb4.name);
 			assertEquals(42, tb4.age);
@@ -198,7 +204,7 @@ public class ApplicationContextExpressionTests {
 	}
 
 
-	public static class ValueTestBean {
+	public static class ValueTestBean implements Serializable {
 
 		@Autowired @Value("XXX#{tb0.name}YYY#{mySpecialAttr}ZZZ")
 		public String name;
@@ -209,8 +215,11 @@ public class ApplicationContextExpressionTests {
 		@Value("${code} #{systemProperties.country}")
 		public String country;
 
+		@Value("${code} #{systemProperties.country}")
+		public ObjectFactory<String> countryFactory;
+
 		@Autowired @Qualifier("original")
-		public TestBean tb;
+		public transient TestBean tb;
 	}
 
 

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

@@ -49,7 +49,9 @@ public class MethodParameter {
 
 	private final int parameterIndex;
 
-	private Class parameterType;
+	private Class<?> parameterType;
+
+	private Type genericParameterType;
 
 	private Annotation[] parameterAnnotations;
 
@@ -167,7 +169,7 @@ public class MethodParameter {
 	/**
 	 * Set a resolved (generic) parameter type.
 	 */
-	void setParameterType(Class parameterType) {
+	void setParameterType(Class<?> parameterType) {
 		this.parameterType = parameterType;
 	}
 
@@ -175,7 +177,7 @@ public class MethodParameter {
 	 * Return the type of the method/constructor parameter.
 	 * @return the parameter type (never <code>null</code>)
 	 */
-	public Class getParameterType() {
+	public Class<?> getParameterType() {
 		if (this.parameterType == null) {
 			if (this.parameterIndex < 0) {
 				this.parameterType = (this.method != null ? this.method.getReturnType() : null);
@@ -189,6 +191,24 @@ public class MethodParameter {
 		return this.parameterType;
 	}
 
+	/**
+	 * Return the generic type of the method/constructor parameter.
+	 * @return the parameter type (never <code>null</code>)
+	 */
+	public Type getGenericParameterType() {
+		if (this.genericParameterType == null) {
+			if (this.parameterIndex < 0) {
+				this.genericParameterType = (this.method != null ? this.method.getGenericReturnType() : null);
+			}
+			else {
+				this.genericParameterType = (this.method != null ?
+					this.method.getGenericParameterTypes()[this.parameterIndex] :
+					this.constructor.getGenericParameterTypes()[this.parameterIndex]);
+			}
+		}
+		return this.genericParameterType;
+	}
+
 	/**
 	 * Return the annotations associated with the target method/constructor itself.
 	 */