我应该为JBDC模板使用什么事务管理器使用JPA？

Question

我正在为我的JPA事务使用标准的JPA事务管理器.但是,现在我想添加一些将共享相同"数据源"的JDBC实体.如何使用spring事务使JDBC操作具有事务性？我是否需要切换到JTA事务管理器？是否可以将JPA和JDBC事务服务与相同的数据源一起使用？更好的是,是否可以混合这两笔交易？

更新:@Espen:

我有一个从SimpleJdbcDaoSupport扩展的dao,它使用getSimpleJDBCTemplate.update插入数据库行.当从服务代码抛出RuntimeException时,事务在使用JPATransactionManager时永远不会回滚.它在使用DatasourceTransactionManager时会回滚.我试图调试JPATransactionManager,似乎它永远不会对底层的JDBCConnection执行回滚(我想这是因为数据源不一定是JPA的JDBC).我的配置设置与您在此处解释的完全相同.

这是我的测试代码:

<context:property-placeholder location="classpath:*.properties"/>

<!-- JPA EntityManagerFactory -->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="persistenceXmlLocation"
        value="classpath:/persistence-test.xml" />
    <property name="persistenceProvider">
        <bean class="org.hibernate.ejb.HibernatePersistence" />
    </property>

</bean>

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>

<!--
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"></property>
</bean>
-->

<!-- Database connection pool -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="${database.driverClassName}" />
    <property name="url" value="${database.url}" />
    <property name="username" value="${database.username}" />
    <property name="password" value="${database.password}" />
    <property name="testOnBorrow" value="${database.testOnBorrow}" />
    <property name="validationQuery" value="${database.validationQuery}" />
    <property name="minIdle" value="${database.minIdle}" />
    <property name="maxIdle" value="${database.maxIdle}" />
    <property name="maxActive" value="${database.maxActive}" />
</bean>




<!-- Initialize the database -->
<!--<bean id="databaseInitializer" class="com.vantage.userGroupManagement.logic.StoreDatabaseLoader">
    <property name="dataSource" ref="storeDataSource"/>
</bean>-->

<!-- ANNOTATION SUPPORT -->

<!-- Enable the configuration of transactional behavior based on annotations -->
<tx:annotation-driven transaction-manager="transactionManager"/>

<!-- JPA annotations bean post processor -->
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>

<!-- Exception translation bean post processor (based on Repository annotation) -->
<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>

<!-- throws exception if a required property has not been set -->
<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>


<bean id="userService" class="com.rfc.example.service.UserServiceImpl"> 
    <property name="userDao" ref="userDao"></property>
    <property name="contactDao" ref="contactDao"></property>
    <property name="callRecordingScheduledProgramTriggerDAO" ref="com.rfc.example.dao.CallRecordingScheduledProgramTriggerDAO"></property>
</bean>

<bean id="userDao" class="com.rfc.example.dao.UserDaoJPAImpl" />

<bean id="contactDao" class="com.rfc.example.dao.ContactDaoJPAImpl"></bean>

<bean id="com.rfc.example.dao.CallRecordingScheduledProgramTriggerDAO" class="com.rfc.example.dao.CallRecordingScheduledProgramTriggerDAOJDBCImpl">
    <property name="dataSource" ref="dataSource"></property>
</bean>

这里是道:

@Transactional
public class CallRecordingScheduledProgramTriggerDAOJDBCImpl  extends SimpleJdbcDaoSupport implements CallRecordingScheduledProgramTriggerDAO{
    private static final Log log = LogFactory.getLog(CallRecordingScheduledProgramTriggerDAOJDBCImpl.class);

@SuppressWarnings("unchecked")
public CallRecordingScheduledProgramTrigger save(
        CallRecordingScheduledProgramTrigger entity) {
    log.debug("save -> entity: " + entity);



    String sql = null;
    Map args = new HashMap();

    String agentIdsString = getAgentIdsString(entity.getAgentIds());


    String insertSQL = "insert into call_recording_scheduled_program_trigger" +
            "       (  queue_id, queue_id_string, agent_ids_string, caller_names, caller_numbers, trigger_id, note, callcenter_id, creator_id_string, creator_id) " +
            " values(:queueId, :queueIdString, :agentIdsString, :callerNames, :callerNumbers, :triggerId, :note, :callcenterId , :creatorIdString, :creatorId  )";

    args.put("queueId", entity.getQueueId());
    args.put("agentIdsString",agentIdsString);
    args.put("callerNames", entity.getCallerNames());       
    args.put("queueIdString", entity.getQueueIdString());
    args.put("callerNumbers", entity.getCallerNumbers());
    args.put("triggerId", entity.getTriggerId());
    args.put("note", entity.getNote());
    args.put("callcenterId", entity.getCallcenterId());
    args.put("creatorId", entity.getCreatorId());
    args.put("creatorIdString", entity.getCreatorIdString());

    sql = insertSQL;
    getSimpleJdbcTemplate().update(sql, args);
    System.out.println("saved: ----------" + entity);
    return entity;
}

}

这是调用dao和抛出异常的客户端代码(spring服务)

@Transactional(propagation=Propagation.REQUIRED)
public void jdbcTransactionTest() {
    System.out.println("entity: " );
    CallRecordingScheduledProgramTrigger entity = new CallRecordingScheduledProgramTrigger();

    entity.setCallcenterId(10L);
    entity.setCreatorId(22L);
    entity.setCreatorIdString("sajid");
    entity.setNote(System.currentTimeMillis() + "");
    entity.setQueueId(22);
    entity.setQueueIdString("dddd");
    String triggerId = "id: " + System.currentTimeMillis();
    entity.setTriggerId(triggerId);
    callRecordingScheduledProgramTriggerDAO.save(entity);

    System.out.println("entity saved with id: " + triggerId );

    throw new RuntimeException();
}

注意:使用DatasourceTransactionManager时,代码按预期工作

更新 - 2:

好的,我找到了问题的根本原因.感谢Espen.

我的实体管理器配置是这样的(从春季宠物诊所应用程序复制):

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="persistenceXmlLocation"
        value="classpath:/persistence-test.xml" />
    <property name="persistenceProvider">
        <bean class="org.hibernate.ejb.HibernatePersistence" />
    </property>

</bean>

然后我把它改成这样:

    <bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceXmlLocation"
        value="classpath:/persistence-test.xml" />
    <property name="dataSource" ref="dataSource"/>

    <property name="jpaVendorAdapter">
        <bean
            class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
       <property name="showSql" value="true" />
       <property name="generateDdl" value="true" />
       <property name="databasePlatform" value="org.hibernate.dialect.MySQL5Dialect" />
    </bean>

 </property>
</bean>

现在一切似乎都在运作!谁能解释这两种方法的区别？

Answer 1

可以使用JpaTransactionManager.在同一事务中混合JPA和JDBC代码.

来自Spring 3的JavaDoc的片段:

此事务管理器还支持事务中的直接DataSource访问(即使用相同DataSource的纯JDBC代码).这允许混合访问JPA的服务和使用普通JDBC的服务(不知道JPA)!

您应该知道,JPA会缓存查询并在事务结束时执行所有查询.因此,如果您希望使用JPA在事务中保留一些数据,然后使用JDBC检索数据,那么在尝试使用JDBC代码检索之前,如果没有明确地刷新JPA的持久性上下文,它将无法工作.

使用JDBC代码声明JPA代码在事务中删除了一行的代码示例:

@Test
@Transactional
@Rollback(false)
public void testDeleteCoffeeType() {

    CoffeeType coffeeType = coffeeTypeDao.findCoffeeType(4L);
    final String caffeForte = coffeeType.getName();

    coffeeTypeDao.deleteCoffeeType(coffeeType);
    entityManager.flush();

    int rowsFoundWithCaffeForte = jdbcTemplate
        .queryForInt("SELECT COUNT(*) FROM COFFEE_TYPES where NAME = ?", 
            caffeForte);
    assertEquals(0, rowsFoundWithCaffeForte);
}

如果你喜欢使用JpaTemplate类,只需更换entityManager.flush()与jpaTemplate.flush();

回应Sajids的评论:使用Spring,您可以配置一个支持JPA和JDBC的事务管理器,如下所示:

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

<!-- Transaction manager -->
<bean id="transactionManager" class="org.springframework.orm.jpa
            .JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

和注释驱动版本

@Bean
public JpaTransactionManager transactionManager(EntityManagerFactory emf) {
    JpaTransactionManager jpaTransactionManager = new JpaTransactionManager();
    jpaTransactionManager.setEntityManagerFactory(emf);
    return jpaTransactionManager;
}

为了使其工作,必须使用JdbcTemplate或SimpleJdbcTemplate类执行JDBC查询.对于扩展SimpleJdbcDaoSupport的DAO,您应该使用getSimpleJdbcTemplate(..)方法.

最后让两个DAO方法参与同一个事务,从@Transactional注释的服务类中调用两个DAO方法.使用<tx:annotation-driven>配置中的元素,Spring将使用给定的事务管理器为您处理事务.

在业务层:

public class ServiceClass {..

@Transactional
public void updateDatabase(..) {
  jpaDao.remove(..);
  jdbcDao.insert(..);
}
}

编辑2:然后出了点问题.它完全按照Javadoc中的规定对我有效.您的实体管理器是否具有类似我的bean的数据源属性？只有在将相同的数据源注入实体管理器和扩展的JpaDaoSupport类时,它才会起作用.

<bean id="entityManagerFactoryWithExternalDataSoure" primary="true"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor
                .HibernateJpaVendorAdapter" />
    </property>
    <property name="jpaProperties">
        <value>
            hibernate.format_sql=true
        </value>
    </property>
</bean>