Spring + JPA +Integration using Spring ORM

JPA we cannot use independently means we need ORM tool to implement the JPA

Spring-ORM module

This module helps to integrated JPA+ORM  with Spring to make our job easy...

Two options:-

1. Spring +Hibernate 3.x

2. Spring +JPA+Hibernate 3.x
     it makes your application ORM independent

JPA is standard which was introduce JEE5 JPA 1.0



Step-1
Adding Dependency

        <dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
       </dependency>


         <!-- Hibernate 3.x +JPA Dependency  -->
<dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>3.6.3.Final</version>
        </dependency>
        
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.6.3.Final</version>
        </dependency>



Step-2
Create EntityManagerFactoryBean inside the meta configuration(spring-jpa-hibernate.xml)


   <bean id="strutsJPAEntityFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
      <property name="dataSource" ref="jpadataSource" />
      <property name="packagesToScan" value="com.struts.mvc.dao.entity" />
      <property name="jpaVendorAdapter">
         <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
      </property>
      <property name="jpaProperties">
         <props>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
            <prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.format_sql">true</prop>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
         </props>
      </property>

   </bean>


Step-3
  <bean id="jpadataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource" scope="singleton">
      <property name="driverClassName" value="com.mysql.jdbc.Driver" />
      <property name="url" value="jdbc:mysql://localhost:3306/profile_db" />
      <property name="username" value="root" />
      <property name="password" value="root" />

   </bean>


Step-4
<!-- This is because spring will do transaction management with  jpa-->
    <bean id="jpaTransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
      <property name="entityManagerFactory" ref="strutsJPAEntityFactory" />
   </bean>
   

Step-5
     <!--Below entry is associating jpaTransactionManager with @Transactional annotation   -->
<tx:annotation-driven  transaction-manager="jpaTransactionManager" proxy-target-class="false"/>

  </beans>


Note : without spring transaction we cannot use Spring and JPA integration

Step-6

@Repository("UserDao")
@Scope("singleton")
@Transactional
public class UserDao implements IUserDao{

//LocalContainerEntityManagerFactoryBean
//@PersistenceContext pulls an EntityManager from  LocalContainerEntityManagerFactoryBean bean manage by spring
//container for JPA

@PersistenceContext

private EntityManager entityManager;


@Override
public String persistUser(UserEntity userEntity) {
boolean enabled=TransactionSynchronizationManager.isActualTransactionActive();
   if(enabled) {
 System.out.println("@_@_@__@_@_@YEAP We are     using_________*@@@@@@@@@@@@@@");
}
System.out.println("||||||||||||||||||||||||");
System.out.println(userEntity);
entityManager.persist(userEntity);
System.out.println("||||||||||||||||||||||||");
return "yeap";

}