Question

I’m building an application that needs CRUD operations on two separate databases. The transactions are applied to one database or the other (never both…so no need for JTA is my understanding). My setup is pretty close to what is found here: Multiple database with Spring+Hibernate+JPA

The problem: My server (JBoss AS7) starts up fine. The application reads from both datasources, say DS1 and DS2, BUT it can only manipulate data from DS1. I can see sequences (Oracle 11g) being updated but no table updates. There are no errors/exceptions thrown. I suspect one of my transaction managers isn’t committing.

Below is a list of technologies used and configuration settings…

Tech Stack

• JBoss AS7
• Oracle 11g
• Spring 3.1
• JPA 2
• Hibernate 4.1

persistence-ds1.xml

<persistence 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"
version="2.0">
  <persistence-unit name="pu1">
    <class>com.somepackage.EntityA</class>  
    <class>com.somepackage.EntityB</class>  
    <class>com.somepackage.EntityC</class>
    <validation-mode>CALLBACK</validation-mode>
    <properties>
      <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultNamingStrategy" />
      <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
      <property name="hibernate.hbm2ddl.auto" value="validate" /> 
    </properties>
  </persistence-unit>
</persistence>

persistence-ds2.xml

<persistence 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"
version="2.0">
  <persistence-unit name="pu2">
    <class>com.somepackage.EntityD</class>  
    <class>com.somepackage.EntityE</class>  
    <class>com.somepackage.EntityF</class>
    <validation-mode>CALLBACK</validation-mode>
    <properties>
      <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultNamingStrategy" />
      <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
      <property name="hibernate.hbm2ddl.auto" value="validate" /> 
    </properties>
  </persistence-unit>
</persistence>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xmlns:jee="http://www.springframework.org/schema/jee"
  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/tx
                      http://www.springframework.org/schema/tx/spring-tx.xsd
                      http://www.springframework.org/schema/jee         
                      http://www.springframework.org/schema/jee/spring-jee.xsd">

  <jee:jndi-lookup id="ds1" jndi-name="java:jboss/datasources/DS1"
    expected-type="javax.sql.DataSource" />
  <jee:jndi-lookup id="ds2" jndi-name="java:jboss/datasources/DS2"
    expected-type="javax.sql.DataSource" />     

  <bean id="em1" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
    <property name="entityManagerFactory" ref="emf1" />
    <property name="persistenceUnitName" value="pu1" />
  </bean>
  <bean id="em2" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
    <property name="entityManagerFactory" ref="emf2" />
    <property name="persistenceUnitName" value="pu2" />
  </bean>

  <bean id="emf1" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceXmlLocation" value="classpath*:META-INF/persistence-ds1.xml"/>
    <property name="dataSource" ref="ds1" />
    <property name="jpaVendorAdapter">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="showSql" value="true" />
        <property name="databasePlatform" value="org.hibernate.dialect.Oracle10gDialect" />
      </bean>
    </property>
    <property name="jpaDialect">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
  </bean>
  <bean id="emf2" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceXmlLocation" value="classpath*:META-INF/persistence-ds2.xml"/>
    <property name="dataSource" ref="ds2" />
    <property name="jpaVendorAdapter">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="showSql" value="true" />
        <property name="databasePlatform" value="org.hibernate.dialect.Oracle10gDialect" />
      </bean>
    </property>
    <property name="jpaDialect">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
  </bean>

  <tx:annotation-driven transaction-manager="txm1" />
  <tx:annotation-driven transaction-manager="txm2" />

  <bean id="txm1" class="org.springframework.orm.jpa.JpaTransactionManager">
    <qualifier value="txMgr1"/>
    <property name="entityManagerFactory" ref="emf1" />
    <property name="jpaDialect">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
  </bean>
  <bean id="txm2" class="org.springframework.orm.jpa.JpaTransactionManager">
    <qualifier value="txMgr2"/>
    <property name="entityManagerFactory" ref="emf2" />
    <property name="jpaDialect">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
  </bean>   

</beans>

In my DAOs, I reference the transaction managers at the class-level as follows.

@Transactional("txm1")
public class DAO1 { ... }

@Transactional("txm2")
public class DAO2 { ... }

Answer 1

I resolved my issue!

In my applicationContext.xml, I removed the following.

<tx:annotation-driven transaction-manager="txm1" />
<tx:annotation-driven transaction-manager="txm2" />

And used the following instead.

<tx:annotation-driven />

But here’s what I believe was the kicker (main problem). In my DAOs, I was assigning the two transaction managers at the class-level. But then I was overriding them with the way I was declaring my methods.

@Transactional(readOnly = false, value = "txm1")
public abstract class AbstractJpaDAO1<T extends Serializable> {
...
@Transactional(readOnly = true)
public T findById(final Long id) {...}

@Transactional
public boolean insert(final T entity) {...}

As you can see, the @Transaction annotations on the methods were overriding the the one at the class-level. And because there was no transaction manager specified on the methods, Spring defaulted to “transactionManager”, which I didn’t (and still don’t) have declared in my applicaitonContext.xml. So, it was trying to commit using a transaction manager that didn’t exist.

For the resolution, I just removed the @Transitional annotations on the methods, and kept the one at the class-level.

@Transactional(readOnly = false, value = "txm1")
public abstract class AbstractJpaDAO1<T extends Serializable> {
...
public T findById(final Long id) {...}

public boolean insert(final T entity) {...}

Now everything works! I can read/write to two separate databases.