DATAJPA-445 - Enable constructor injection for EntityManagers.

Enabling repositories now registers a BeanFactoryPostProcessor that will register a SharedEntityManagerCreator BeanDefinition for all EntityManagerFactory definitions available in the ApplicationContext.

We register the bean name of the EMF as qualifier for the BeanDefinition for the EntityManager to allow an explicit reference in multi-EMF scenarios.

Renamed default persistence unit to spring-data-jpa.

src/main/java/org/springframework/data/jpa/repository/config/JpaRepositoryConfigExtension.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -22,10 +22,12 @@ import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.annotation.AnnotationConfigUtils;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.dao.DataAccessException;
 import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
+import org.springframework.data.jpa.repository.support.EntityManagerBeanDefinitionRegistrarPostProcessor;
 import org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean;
 import org.springframework.data.repository.config.AnnotationRepositoryConfigurationSource;
 import org.springframework.data.repository.config.RepositoryConfigurationExtensionSupport;
@@ -137,13 +139,14 @@ public class JpaRepositoryConfigExtension extends RepositoryConfigurationExtensi
 
 		super.registerBeansForRoot(registry, configurationSource);
 
+		Object source = configurationSource.getSource();
+		registerWithSourceAndGeneratedBeanName(registry, new RootBeanDefinition(
+				EntityManagerBeanDefinitionRegistrarPostProcessor.class), source);
+
 		if (!hasBean(PAB_POST_PROCESSOR, registry)
 				&& !registry.containsBeanDefinition(AnnotationConfigUtils.PERSISTENCE_ANNOTATION_PROCESSOR_BEAN_NAME)) {
 
-			AbstractBeanDefinition definition = BeanDefinitionBuilder.rootBeanDefinition(PAB_POST_PROCESSOR)
-					.getBeanDefinition();
-
-			registerWithSourceAndGeneratedBeanName(registry, definition, configurationSource.getSource());
+			registerWithSourceAndGeneratedBeanName(registry, new RootBeanDefinition(PAB_POST_PROCESSOR), source);
 		}
 	}
 }

src/main/java/org/springframework/data/jpa/repository/support/EntityManagerBeanDefinitionRegistrarPostProcessor.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2014 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.data.jpa.repository.support;
+
+import static java.util.Arrays.*;
+import static org.springframework.beans.factory.BeanFactoryUtils.*;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
+import org.springframework.beans.factory.support.AutowireCandidateQualifier;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.orm.jpa.AbstractEntityManagerFactoryBean;
+import org.springframework.orm.jpa.SharedEntityManagerCreator;
+
+/**
+ * {@link BeanFactoryPostProcessor} to register a {@link SharedEntityManagerCreator} for every
+ * {@link EntityManagerFactory} bean definition found in the application context to enable autowiring
+ * {@link EntityManager} instances into constructor arguments. Adds the {@link EntityManagerFactory} bean name as
+ * qualifier to the {@link EntityManager} {@link BeanDefinition} to enable explicit references in case of multiple
+ * {@link EntityManagerFactory} instances.
+ * 
+ * @author Oliver Gierke
+ */
+public class EntityManagerBeanDefinitionRegistrarPostProcessor implements BeanFactoryPostProcessor {
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.beans.factory.config.BeanFactoryPostProcessor#postProcessBeanFactory(org.springframework.beans.factory.config.ConfigurableListableBeanFactory)
+	 */
+	@Override
+	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
+
+		if (!(beanFactory instanceof BeanDefinitionRegistry)) {
+			return;
+		}
+
+		for (String emfName : getEntityManagerFactoryBeanNames(beanFactory)) {
+
+			BeanDefinitionBuilder builder = BeanDefinitionBuilder
+					.rootBeanDefinition("org.springframework.orm.jpa.SharedEntityManagerCreator");
+			builder.setFactoryMethod("createSharedEntityManager");
+			builder.addConstructorArgReference(emfName);
+
+			AbstractBeanDefinition emBeanDefinition = builder.getRawBeanDefinition();
+			AbstractBeanDefinition emfBeanDefinition = (AbstractBeanDefinition) beanFactory.getBeanDefinition(emfName);
+
+			emBeanDefinition.addQualifier(new AutowireCandidateQualifier(Qualifier.class, emfName));
+			emBeanDefinition.setScope(emfBeanDefinition.getScope());
+			emBeanDefinition.setSource(emfBeanDefinition.getSource());
+
+			BeanDefinitionReaderUtils.registerWithGeneratedName(emBeanDefinition, (BeanDefinitionRegistry) beanFactory);
+		}
+	}
+
+	/**
+	 * Return all bean names for bean definitions that will result in an {@link EntityManagerFactory} eventually. We're
+	 * checking for {@link EntityManagerFactory} and the well-known factory beans here to avoid eager initialization of
+	 * the factory beans. The double lookup is necessary especially for JavaConfig scenarios as people might declare an
+	 * {@link EntityManagerFactory} directly.
+	 * 
+	 * @param beanFactory
+	 * @return
+	 */
+	private static Iterable<String> getEntityManagerFactoryBeanNames(ListableBeanFactory beanFactory) {
+
+		Set<String> names = new HashSet<String>();
+		names.addAll(asList(beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class, true, false)));
+
+		for (String factoryBeanName : beanNamesForTypeIncludingAncestors(beanFactory,
+				AbstractEntityManagerFactoryBean.class, true, false)) {
+			names.add(factoryBeanName.substring(1));
+		}
+
+		return names;
+	}
+}

src/test/java/org/springframework/data/jpa/repository/config/InfrastructureConfig.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 the original author or authors.
+ * Copyright 2013-2014 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.
@@ -32,6 +32,7 @@ import org.springframework.transaction.annotation.EnableTransactionManagement;
  * Reusable config class for testing pure java based Spring configuration.
  * 
  * @author Thomas Darimont
+ * @author Oliver Gierke
  */
 @Configuration
 @EnableTransactionManagement
@@ -61,6 +62,7 @@ public class InfrastructureConfig {
 	public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
 
 		LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+		em.setPersistenceUnitName("spring-data-jpa");
 		em.setDataSource(dataSource());
 		em.setJpaVendorAdapter(jpaVendorAdapter());
 		em.setPackagesToScan("purejavaconfig");

src/test/java/org/springframework/data/jpa/repository/config/JpaRepositoriesRegistrarIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -55,11 +55,9 @@ import org.springframework.util.ClassUtils;
 @ContextConfiguration
 public class JpaRepositoriesRegistrarIntegrationTests {
 
-	@Autowired
-	UserRepository repository;
+	@Autowired UserRepository repository;
 
-	@Autowired
-	SampleRepository sampleRepository;
+	@Autowired SampleRepository sampleRepository;
 
 	@Configuration
 	@EnableJpaRepositories(basePackages = "org.springframework.data.jpa.repository.sample")
@@ -74,7 +72,7 @@ public class JpaRepositoriesRegistrarIntegrationTests {
 		public EntityManagerFactory entityManagerFactory() {
 			LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
 			factory.setDataSource(dataSource());
-			factory.setPersistenceUnitName("default");
+			factory.setPersistenceUnitName("spring-data-jpa");
 			factory.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
 			factory.afterPropertiesSet();
 			return factory.getObject();

src/test/java/org/springframework/data/jpa/repository/support/EntityManagerBeanDefinitionRegistrarPostProcessorIntegrationTests.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright 2014 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.data.jpa.repository.support;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import javax.persistence.EntityManager;
+import javax.sql.DataSource;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.ComponentScan.Filter;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.ImportResource;
+import org.springframework.orm.jpa.JpaVendorAdapter;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.stereotype.Component;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * Integration tests for {@link EntityManagerBeanDefinitionRegistrarPostProcessor}.
+ * 
+ * @author Oliver Gierke
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration
+public class EntityManagerBeanDefinitionRegistrarPostProcessorIntegrationTests {
+
+	@Configuration
+	@ImportResource("classpath:infrastructure.xml")
+	@ComponentScan(includeFilters = @Filter(TestComponent.class), useDefaultFilters = false)
+	static class Config {
+
+		@Autowired DataSource dataSource;
+		@Autowired JpaVendorAdapter vendorAdapter;
+
+		@Bean
+		public static EntityManagerBeanDefinitionRegistrarPostProcessor processor() {
+			return new EntityManagerBeanDefinitionRegistrarPostProcessor();
+		}
+
+		private LocalContainerEntityManagerFactoryBean emf() {
+
+			LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();
+			factoryBean.setPersistenceUnitName("spring-data-jpa");
+			factoryBean.setDataSource(dataSource);
+			factoryBean.setJpaVendorAdapter(vendorAdapter);
+
+			return factoryBean;
+		}
+
+		@Bean
+		LocalContainerEntityManagerFactoryBean firstEmf() {
+			return emf();
+		}
+
+		@Bean
+		LocalContainerEntityManagerFactoryBean secondEmf() {
+			return emf();
+		}
+	}
+
+	@Autowired EntityManagerInjectionTarget target;
+
+	/**
+	 * @see
+	 */
+	@Test
+	public void foo() {
+
+		assertThat(target, is(notNullValue()));
+		assertThat(target.em, is(notNullValue()));
+	}
+
+	@TestComponent
+	static class EntityManagerInjectionTarget {
+
+		private final EntityManager em;
+
+		@Autowired
+		public EntityManagerInjectionTarget(@Qualifier("firstEmf") EntityManager em) {
+			this.em = em;
+		}
+	}
+
+	/**
+	 * Annotation to demarcate test components.
+	 * 
+	 * @author Oliver Gierke
+	 */
+	@Component
+	@Retention(RetentionPolicy.RUNTIME)
+	@Target(ElementType.TYPE)
+	static @interface TestComponent {
+
+	}
+}

src/test/resources/META-INF/persistence.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
-	<persistence-unit name="default">
+	<persistence-unit name="spring-data-jpa">
 		<class>org.springframework.data.jpa.domain.sample.AbstractMappedType</class>
 		<class>org.springframework.data.jpa.domain.AbstractPersistable</class>
 		<class>org.springframework.data.jpa.domain.AbstractAuditable</class>
@@ -91,5 +91,5 @@
 	        <property name="openjpa.ConnectionPassword" value="" />
 		</properties>
 	</persistence-unit>
-	
+
 </persistence>

src/test/resources/infrastructure.xml

@@ -10,7 +10,7 @@
 	<bean id="entityManagerFactory"
 		class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
 		<property name="dataSource" ref="dataSource" />
-		<property name="persistenceUnitName" value="default" />
+		<property name="persistenceUnitName" value="spring-data-jpa" />
 		<property name="jpaVendorAdapter" ref="vendorAdaptor" />
 		<property name="jpaProperties" ref="jpaProperties" />
 	</bean>