ObjectFactoryCreatingFactoryBean creates a serializable ObjectFactory reference; added ProviderCreatingFactoryBean, exposing a serializable JSR-330 Provider reference (SPR-6998)

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

@@ -16,7 +16,10 @@
 
 package org.springframework.beans.factory.config;
 
+import java.io.Serializable;
+
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.util.Assert;
 
@@ -41,7 +44,7 @@ import org.springframework.util.Assert;
  * <pre class="code">&lt;beans&gt;
  *
  *   &lt;!-- Prototype bean since we have state --&gt;
- *   &lt;bean id="myService" class="a.b.c.MyService" singleton="false"/&gt;
+ *   &lt;bean id="myService" class="a.b.c.MyService" scope="prototype"/&gt;
  *
  *   &lt;bean id="myServiceFactory"
  *       class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean"&gt;
@@ -63,9 +66,9 @@ import org.springframework.util.Assert;
  *
  * public class MyClientBean {
  *
- *   private ObjectFactory myServiceFactory;
+ *   private ObjectFactory&lt;MyService&gt; myServiceFactory;
  *
- *   public void setMyServiceFactory(ObjectFactory myServiceFactory) {
+ *   public void setMyServiceFactory(ObjectFactory&lt;MyService&gt; myServiceFactory) {
  *     this.myServiceFactory = myServiceFactory;
  *   }
  *
@@ -98,13 +101,10 @@ public class ObjectFactoryCreatingFactoryBean extends AbstractFactoryBean<Object
 
 	/**
 	 * Set the name of the target bean.
-	 * <p>The target does not <i>have</> to be a prototype bean, but realisticially
+	 * <p>The target does not <i>have</> to be a non-singleton bean, but realisticially
-	 * always will be (because if the target bean were a singleton, then said
+	 * always will be (because if the target bean were a singleton, then said singleton
-	 * singleton bean could simply be injected straight into the dependent object,
+	 * bean could simply be injected straight into the dependent object, thus obviating
-	 * thus obviating the need for the extra level of indirection afforded by
+	 * the need for the extra level of indirection afforded by this factory approach).
-	 * the approach encapsulated by this class). Please note that no exception
-	 * will be thrown if the supplied <code>targetBeanName</code> does not
-	 * reference a prototype bean.
 	 */
 	public void setTargetBeanName(String targetBeanName) {
 		this.targetBeanName = targetBeanName;
@@ -124,21 +124,27 @@ public class ObjectFactoryCreatingFactoryBean extends AbstractFactoryBean<Object
 
 	@Override
 	protected ObjectFactory createInstance() {
-		return new ObjectFactory() {
+		return new TargetBeanObjectFactory(getBeanFactory(), this.targetBeanName);
-			public Object getObject() throws BeansException {
-				return getTargetBean(targetBeanName);
-			}
-		};
 	}
 
+
 	/**
-	 * Template method for obtaining a target bean instance.
+	 * Independent inner class - for serialization purposes.
-	 * Called by the exposed ObjectFactory's <code>getObject()</code> method.
-	 * @param targetBeanName the name of the target bean
-	 * @return the target bean instance
 	 */
-	protected Object getTargetBean(String targetBeanName) {
+	private static class TargetBeanObjectFactory implements ObjectFactory, Serializable {
-		return getBeanFactory().getBean(targetBeanName);
+
+		private final BeanFactory beanFactory;
+
+		private final String targetBeanName;
+
+		public TargetBeanObjectFactory(BeanFactory beanFactory, String targetBeanName) {
+			this.beanFactory = beanFactory;
+			this.targetBeanName = targetBeanName;
+		}
+
+		public Object getObject() throws BeansException {
+			return this.beanFactory.getBean(this.targetBeanName);
+		}
 	}
 
 }

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

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2002-2010 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.beans.factory.config;
+
+import java.io.Serializable;
+import javax.inject.Provider;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.util.Assert;
+
+/**
+ * A {@link org.springframework.beans.factory.FactoryBean} implementation that
+ * returns a value which is a JSR-330 {@link javax.inject.Provider} that in turn
+ * returns a bean sourced from a {@link org.springframework.beans.factory.BeanFactory}.
+ *
+ * <p>This is basically a JSR-330 compliant variant of Spring's good old
+ * {@link ObjectFactoryCreatingFactoryBean}. It can be used for traditional
+ * external dependency injection configuration that targets a property or
+ * constructor argument of type <code>javax.inject.Provider</code>, as an
+ * alternative to JSR-330's <code>@Inject</code> annotation-driven approach.
+ *
+ * @author Juergen Hoeller
+ * @since 3.0.2
+ * @see javax.inject.Provider
+ * @see ObjectFactoryCreatingFactoryBean
+ */
+public class ProviderCreatingFactoryBean extends AbstractFactoryBean<Provider> {
+
+	private String targetBeanName;
+
+
+	/**
+	 * Set the name of the target bean.
+	 * <p>The target does not <i>have</> to be a non-singleton bean, but realisticially
+	 * always will be (because if the target bean were a singleton, then said singleton
+	 * bean could simply be injected straight into the dependent object, thus obviating
+	 * the need for the extra level of indirection afforded by this factory approach).
+	 */
+	public void setTargetBeanName(String targetBeanName) {
+		this.targetBeanName = targetBeanName;
+	}
+
+	@Override
+	public void afterPropertiesSet() throws Exception {
+		Assert.hasText(this.targetBeanName, "Property 'targetBeanName' is required");
+		super.afterPropertiesSet();
+	}
+
+
+	@Override
+	public Class getObjectType() {
+		return Provider.class;
+	}
+
+	@Override
+	protected Provider createInstance() {
+		return new TargetBeanProvider(getBeanFactory(), this.targetBeanName);
+	}
+
+
+	/**
+	 * Independent inner class - for serialization purposes.
+	 */
+	private static class TargetBeanProvider implements Provider, Serializable {
+
+		private final BeanFactory beanFactory;
+
+		private final String targetBeanName;
+
+		public TargetBeanProvider(BeanFactory beanFactory, String targetBeanName) {
+			this.beanFactory = beanFactory;
+			this.targetBeanName = targetBeanName;
+		}
+
+		public Object get() throws BeansException {
+			return this.beanFactory.getBean(this.targetBeanName);
+		}
+	}
+
+}

org.springframework.beans/src/test/java/org/springframework/beans/factory/config/ObjectFactoryCreatingFactoryBeanTests-context.xml

@@ -1,19 +1,24 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd">
 
-<!--
-  Test data for ObjectFactoryCreatingFactoryBeanTests
--->
 <beans>
 	
 	<bean id="prototypeTarget" class="java.util.Date" scope="prototype"/>
 
-	<bean id="prototype" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean">
+	<bean id="prototypeFactory" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean">
-		<property name="targetBeanName"><idref local="prototypeTarget"/></property>
+		<property name="targetBeanName" value="prototypeTarget"/>
 	</bean>
 
-	<bean id="testBean" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBeanTests$TestBean">
+	<bean id="factoryTestBean" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBeanTests$FactoryTestBean">
-		<property name="objectFactory"><ref local="prototype"/></property>
+		<property name="objectFactory" ref="prototypeFactory"/>
 	</bean>
-  
+
+	<bean id="prototypeProvider" class="org.springframework.beans.factory.config.ProviderCreatingFactoryBean">
+		<property name="targetBeanName" value="prototypeTarget"/>
+	</bean>
+
+	<bean id="providerTestBean" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBeanTests$ProviderTestBean">
+		<property name="provider" ref="prototypeProvider"/>
+	</bean>
+
 </beans>

org.springframework.beans/src/test/java/org/springframework/beans/factory/config/ObjectFactoryCreatingFactoryBeanTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -16,43 +16,49 @@
 
 package org.springframework.beans.factory.config;
 
-import static org.easymock.EasyMock.*;
-import static org.junit.Assert.*;
-import static test.util.TestResourceUtils.qualifiedResource;
-
 import java.util.Date;
+import javax.inject.Provider;
 
+import static org.easymock.EasyMock.*;
+import org.junit.After;
+import static org.junit.Assert.*;
 import org.junit.Before;
 import org.junit.Test;
-import org.springframework.beans.BeansException;
+import static test.util.TestResourceUtils.*;
+
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.xml.XmlBeanFactory;
 import org.springframework.core.io.Resource;
+import org.springframework.util.SerializationTestUtils;
 
 /**
- * Unit tests for {@link ObjectFactoryCreatingFactoryBean}.
- *
  * @author Colin Sampaleanu
+ * @author Juergen Hoeller
  * @author Rick Evans
  * @author Chris Beams
- * @since 2004-05-11
  */
-public final class ObjectFactoryCreatingFactoryBeanTests {
+public class ObjectFactoryCreatingFactoryBeanTests {
 
 	private static final Resource CONTEXT =
 		qualifiedResource(ObjectFactoryCreatingFactoryBeanTests.class, "context.xml");
 	
-	private BeanFactory beanFactory;
+	private XmlBeanFactory beanFactory;
 
 	@Before
 	public void setUp() {
 		this.beanFactory = new XmlBeanFactory(CONTEXT);
+		this.beanFactory.setSerializationId("test");
+	}
+
+	@After
+	public void tearDown() {
+		this.beanFactory.setSerializationId(null);
 	}
 
 	@Test
-	public void testBasicOperation() throws BeansException {
+	public void testFactoryOperation() throws Exception {
-		TestBean testBean = (TestBean) beanFactory.getBean("testBean");
+		FactoryTestBean testBean = beanFactory.getBean("factoryTestBean", FactoryTestBean.class);
 		ObjectFactory<?> objectFactory = testBean.getObjectFactory();
 
 		Date date1 = (Date) objectFactory.getObject();
@@ -60,6 +66,40 @@ public final class ObjectFactoryCreatingFactoryBeanTests {
 		assertTrue(date1 != date2);
 	}
 
+	@Test
+	public void testFactorySerialization() throws Exception {
+		FactoryTestBean testBean = beanFactory.getBean("factoryTestBean", FactoryTestBean.class);
+		ObjectFactory<?> objectFactory = testBean.getObjectFactory();
+
+		objectFactory = (ObjectFactory) SerializationTestUtils.serializeAndDeserialize(objectFactory);
+
+		Date date1 = (Date) objectFactory.getObject();
+		Date date2 = (Date) objectFactory.getObject();
+		assertTrue(date1 != date2);
+	}
+
+	@Test
+	public void testProviderOperation() throws Exception {
+		ProviderTestBean testBean = beanFactory.getBean("providerTestBean", ProviderTestBean.class);
+		Provider<?> provider = testBean.getProvider();
+
+		Date date1 = (Date) provider.get();
+		Date date2 = (Date) provider.get();
+		assertTrue(date1 != date2);
+	}
+
+	@Test
+	public void testProviderSerialization() throws Exception {
+		ProviderTestBean testBean = beanFactory.getBean("providerTestBean", ProviderTestBean.class);
+		Provider<?> provider = testBean.getProvider();
+
+		provider = (Provider) SerializationTestUtils.serializeAndDeserialize(provider);
+
+		Date date1 = (Date) provider.get();
+		Date date2 = (Date) provider.get();
+		assertTrue(date1 != date2);
+	}
+
 	@Test
 	public void testDoesNotComplainWhenTargetBeanNameRefersToSingleton() throws Exception {
 		final String targetBeanName = "singleton";
@@ -78,7 +118,6 @@ public final class ObjectFactoryCreatingFactoryBeanTests {
 		assertSame(expectedSingleton, actualSingleton);
 		
 		verify(beanFactory);
-
 	}
 
 	@Test
@@ -119,10 +158,9 @@ public final class ObjectFactoryCreatingFactoryBeanTests {
 	}
 
 
-	public static class TestBean {
+	public static class FactoryTestBean {
-
-		public ObjectFactory<?> objectFactory;
 
+		private ObjectFactory<?> objectFactory;
 
 		public ObjectFactory<?> getObjectFactory() {
 			return objectFactory;
@@ -131,7 +169,20 @@ public final class ObjectFactoryCreatingFactoryBeanTests {
 		public void setObjectFactory(ObjectFactory<?> objectFactory) {
 			this.objectFactory = objectFactory;
 		}
+	}
 
+
+	public static class ProviderTestBean {
+
+		private Provider<?> provider;
+
+		public Provider<?> getProvider() {
+			return provider;
+		}
+
+		public void setProvider(Provider<?> provider) {
+			this.provider = provider;
+		}
 	}
 
 }