spring+jpa 兩個資料來源配置
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
<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>
<!-- 事務管理 -->
<bean id="transactionManager"
class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<!-- 將事務管理加到標有 @Transactional 的類或者方法上 -->
<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>
<!-- 事務管理 -->
<bean id="transactionManager2"
class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory2" />
</bean>
<!-- 將事務管理加到標有 @Transactional 的類或者方法上 -->
<tx:annotation-driven transaction-manager="govtransactionManager2" />
</beans>
3. dao註解管理事務
建立兩個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;
}
用兩個dao分開連結資料庫。
實現類繼承basedao或basedao2即可。
補充：service新增事務工廠，則需要改變一些配置。
1.兩個資料庫對應的事務各新增一句 <qualifier value="aaaEM" />
例如：
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
<qualifier value="aaaEM" />
</bean>
2. 新增之後，會提示出錯，不支援qualifier 。
則將applicationContext.xml的頭部更改為：
<?xml version="1.0" encoding="UTF-8"?>
。
到此完成。
配置過程中遇到的問題：
配置完成後，啟動專案應該達到自動建立資料庫的效果。
控制檯列印錯誤：
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [javax.persistence.EntityManagerFactory] is defined: expected single bean but found 2
如果認真觀察的話，上面應該還會提示在建立哪個bean的時候提示出錯。
那麼提示錯誤的bean裡面應該有用到EntityManagerFactory。
解決辦法：對set方法添加註解，如：
@PersistenceUnit(unitName="aaaUnit")
public void setEntityManagerFactory(EntityManagerFactory emf) {
this.emf = emf;
}
這樣來區分資料來源。
重啟，ok。