spring+jpa 两个数据源配置

1. META-INF/persistence.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/persistencehttp://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"

version="1.0">

<persistence-unit name="aaaUnit" transaction-type="RESOURCE_LOCAL">

<provider>org.hibernate.ejb.HibernatePersistence</provider>

<properties>

<property name="hibernate.hbm2ddl.auto" value="update" />

<property name="hibernate.jdbc.fetch_size" value="18" />

<property name="hibernate.jdbc.batch_size" value="10" />

<property name="hibernate.show_sql" value="false" />

<property name="hibernate.format_sql" value="true" />

<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"/>

</properties>

</persistence-unit>

<!-- *********************************************** -->

<persistence-unit name="bbbUnit" transaction-type="RESOURCE_LOCAL">

<provider>org.hibernate.ejb.HibernatePersistence</provider>

<properties>

<property name="hibernate.hbm2ddl.auto" value="update" />

<property name="hibernate.jdbc.fetch_size" value="18" />

<property name="hibernate.jdbc.batch_size" value="10" />

<property name="hibernate.show_sql" value="false" />

<property name="hibernate.format_sql" value="true" />

<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"/>

</properties>

</persistence-unit>

</persistence>

2.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:aop="http://www.springframework.org/schema/aop"

xmlns:tx="http://www.springframework.org/schema/tx"

xsi:schemaLocation="

http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-2.0.xsd

http://www.springframework.org/schema/txhttp://www.springframework.org/schema/tx/spring-tx-2.0.xsd

http://www.springframework.org/schema/aophttp://www.springframework.org/schema/aop/spring-aop-2.0.xsd">

<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

<bean id="userService" class="hr.gov.serviceImpl.userServiceImpl"/>

<!-- ******************************************************** -->

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">

<property name="driverClass" value="com.mysql.jdbc.Driver" />

<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/aaa?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=round" />

<property name="user" value="" />

<property name="password" value=""/>

<property name="minPoolSize" value="1" />

<property name="maxPoolSize" value="20"/>

<property name="initialPoolSize" value="1"/>

<property name="maxIdleTime" value="25000"/>

<property name="acquireIncrement" value="1"/>

<property name="acquireRetryAttempts" value="30"/>

<property name="acquireRetryDelay" value="1000"/>

<property name="testConnectionOnCheckin" value="true"/>

<property name="automaticTestTable" value="c3p0TestTable"/>

<property name="idleConnectionTestPeriod" value="18000"/>

<property name="checkoutTimeout" value="3000"/>

</bean>

<bean id="entityManagerFactory" autowire="byName"

class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">

<property name="persistenceUnitName" value="aaaUnit" />

<property name="dataSource" ref="dataSource" />

<property name="jpaVendorAdapter">

<bean

class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">

<property name="database" value="MYSQL" />

<property name="showSql" value="false" />

</bean>

</property>

</bean>

<!-- 事务管理 -->

<bean id="transactionManager"

class="org.springframework.orm.jpa.JpaTransactionManager">

<property name="entityManagerFactory" ref="entityManagerFactory" />

</bean>

<!-- 将事务管理加到标有 @Transactional 的类或者方法上 -->

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

<!-- ********************************************************* -->

<bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">

<property name="driverClass" value="com.mysql.jdbc.Driver" />

<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/bbb?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=round" />

<property name="user" value="" />

<property name="password" value="" />

<property name="minPoolSize" value="1" />

<property name="maxPoolSize" value="20"/>

<property name="initialPoolSize" value="1"/>

<property name="maxIdleTime" value="25000"/>

<property name="acquireIncrement" value="1"/>

<property name="acquireRetryAttempts" value="30"/>

<property name="acquireRetryDelay" value="1000"/>

<property name="testConnectionOnCheckin" value="true"/>

<property name="automaticTestTable" value="c3p0TestTable"/>

<property name="idleConnectionTestPeriod" value="18000"/>

<property name="checkoutTimeout" value="3000"/>

</bean>

<bean id="entityManagerFactory2" autowire="byName"

class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">

<property name="persistenceUnitName" value="bbbUnit" />

<property name="dataSource" ref="dataSource2" />

<property name="jpaVendorAdapter">

<bean

class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">

<property name="database" value="MYSQL" />

<property name="showSql" value="false" />

</bean>

</property>

</bean>

<!-- 事务管理 -->

<bean id="transactionManager2"

class="org.springframework.orm.jpa.JpaTransactionManager">

<property name="entityManagerFactory" ref="entityManagerFactory2" />

</bean>

<!-- 将事务管理加到标有 @Transactional 的类或者方法上 -->

<tx:annotation-driven transaction-manager="govtransactionManager2" />

</beans>

3. dao注解管理事务

建立两个baseDaoImpl：

public EntityManager entityManager;

private EntityManagerFactory emf;

public EntityManager getEntityManager() {

return entityManager;

}

@PersistenceContext(unitName="aaaUnit")

public void setEntityManager(EntityManager entityManager) {

this.entityManager = entityManager;

}

@PersistenceUnit(unitName="aaaUnit")

public void setEntityManagerFactory(EntityManagerFactory emf) {

this.emf = emf;

}

baseDaoImpl2:

public EntityManager entityManager;

private EntityManagerFactory emf;

public EntityManager getEntityManager() {

return entityManager;

}

@PersistenceContext(unitName="aaaUnit")

public void setEntityManager(EntityManager entityManager) {

this.entityManager = entityManager;

}

@PersistenceUnit(unitName="aaaUnit")

public void setEntityManagerFactory(EntityManagerFactory emf) {

this.emf = emf;

}

用两个dao分开链接数据库。

实现类继承basedao或basedao2即可。

补充：service添加事务工厂，则需要改变一些配置。

1.两个数据库对应的事务各添加一句 <qualifier value="aaaEM" />

例如：

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">

<property name="entityManagerFactory" ref="entityManagerFactory" />

<qualifier value="aaaEM" />

</bean>

2. 添加之后，会提示出错，不支持qualifier 。

则将applicationContext.xml的头部更改为：

<?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: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-3.0.xsd">
。

到此完成。

配置过程中遇到的问题：

配置完成后，启动项目应该达到自动建立数据库的效果。

控制台打印错误：

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [javax.persistence.EntityManagerFactory] is defined: expected single bean but found 2

如果认真观察的话，上面应该还会提示在创建哪个bean的时候提示出错。

那么提示错误的bean里面应该有用到EntityManagerFactory。

解决办法：对set方法添加注解，如：

@PersistenceUnit(unitName="aaaUnit")

public void setEntityManagerFactory(EntityManagerFactory emf) {

this.emf = emf;

}

这样来区分数据源。

重启，ok。

参考文章：/article/3578812.html