Example: how to start EclipseLink (or other JPA) transaction declaratively in Spring

Here is example of declarative transaction management with EclipseLink JPA provider in Spring-based application. Similar approach should work with other JPA providers as well.
I use Maven for building so these were the required dependencies:

view plainprint?

1. <dependency>  
2.  <groupid>org.eclipse.persistence</groupid>  
3.  <artifactid>javax.persistence</artifactid>  
4.  <version>2.0.0</version>  
5. </dependency>  
6. <dependency>  
7.  <groupid>org.aspectj</groupid>  
8.  <artifactid>aspectjrt</artifactid>  
9.  <version>1.6.9</version>  
10. </dependency>  
11. <dependency>  
12.  <groupid>org.springframework</groupid>  
13.  <artifactid>spring-aspects</artifactid>  
14.  <version>3.0.4.RELEASE</version>  
15. </dependency>  

 org.eclipse.persistence
 javax.persistence
 2.0.0


 org.aspectj
 aspectjrt
 1.6.9


 org.springframework
 spring-aspects
 3.0.4.RELEASE

Here is Spring's application context file:

view plainprint?

1. <!--xml version="1.0" encoding="UTF-8"?-->  
2. <beans xmlns="http://www.springframework.org/schema/beans" <brbr="">  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
3.   xmlns:context="http://www.springframework.org/schema/context"   
4.   xmlns:aop="http://www.springframework.org/schema/aop"   
5.   xmlns:tx="http://www.springframework.org/schema/tx"   
6.   xsi:schemaLocation="http://www.springframework.org/schema/beans  
7.   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
8.   http://www.springframework.org/schema/context  
9.   http://www.springframework.org/schema/context/spring-context-3.0.xsd  
10.   http://www.springframework.org/schema/aop  
11.   http://www.springframework.org/schema/aop/spring-aop-2.0.xsd  
12.   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd ">  
13.   
14.   <context:annotation-config>  
15.   <context:component-scan base-package="your.services.package">  
16.   <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor">  
17.   <tx:annotation-driven transaction-manager="txManager">  
18.   <aop:spring-configured>  
19.   
20.   <bean id="txManager" class="org.springframework.orm.jpa.JpaTransactionManager">  
21.    <property name="entityManagerFactory" ref="emf">  
22.   </property></bean>  
23.   <bean id="jpaAdapter" class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">  
24.     <property name="databasePlatform" value="org.eclipse.persistence.platform.database.OraclePlatform">  
25.     <property name="showSql" value="true">  
26.   </property></property></bean>  
27.   <bean id="emf" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">  
28.    <property name="persistenceUnitName" value="your_persistence_unit_name">  
29.    <property name="jpaVendorAdapter" ref="jpaAdapter">  
30.   </property></property></bean>  
31. </aop:spring-configured></tx:annotation-driven></bean></context:component-scan></context:annotation-config></beans>  

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xmlns:context="http://www.springframework.org/schema/context" 
  xmlns:aop="http://www.springframework.org/schema/aop" 
  xmlns:tx="http://www.springframework.org/schema/tx" 
  xsi:schemaLocation="http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
  http://www.springframework.org/schema/context
  http://www.springframework.org/schema/context/spring-context-3.0.xsd
  http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
  http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd ">

  
  
  
  
  

  
   
  
  
    
    
  
  
   
   
  

Now inside of your.services.package you can have such class:

view plainprint?

1. @Component //instantiate as Spring's bean  
2. public class ProductServiceImpl implements ProductService {  
3.  //Trick part #1 - Spring substitutes here entity manager   
4.  //and handles it in a way that each thread thinks he's the only one working with this manager.  
5.  //For E.M. marked by this annotation declarative transaction management is possible  
6.  @PersistenceContext(type = PersistenceContextType.TRANSACTION)   
7.  private EntityManager containerEm;  
8.   
9.  //Trick part #2 - Spring wraps this method in transaction which is handled by containerEm  
10.  @Transactional(readOnly=false, propagation=Propagation.REQUIRED)  
11.  public void yourMethod() {  
12.    ...  
13.    //Here you can do whatever you want with E.M.:  
14.    containerEm.createNativeQuery(...);  
15.    //or  
16.    em.persist(...);  
17.    //etc.  
18.    ...  
19.  }//end of transactional method  
20.   
21. }  

@Component //instantiate as Spring's bean
public class ProductServiceImpl implements ProductService {
 //Trick part #1 - Spring substitutes here entity manager 
 //and handles it in a way that each thread thinks he's the only one working with this manager.
 //For E.M. marked by this annotation declarative transaction management is possible
 @PersistenceContext(type = PersistenceContextType.TRANSACTION) 
 private EntityManager containerEm;

 //Trick part #2 - Spring wraps this method in transaction which is handled by containerEm
 @Transactional(readOnly=false, propagation=Propagation.REQUIRED)
 public void yourMethod() {
   ...
   //Here you can do whatever you want with E.M.:
   containerEm.createNativeQuery(...);
   //or
   em.persist(...);
   //etc.
   ...
 }//end of transactional method

}