Spring 对事务管理的支持

Z时代
2024-01-10
分类：综合

本文内容纲要：Spring 对事务管理的支持

1、Spring对事务管理的支持

Spring为事务管理提供了一致的编程模板，在高层次建立了统一的事务抽象。也就是说，不管选择Spring JDBC、Hibernate 、JPA 还是iBatis，Spring都让我们可以用统一的编程模型进行事务管理。

在Spring事务管理SPI（Service Provider Interface）的抽象层主要包括3个接口，分别是PlatformTransactionManager、TransactionDefinition和TransactionStatus。TransactionDefinition用于描述事务的隔离级别、超时时间、是否为只读事务和事务传播规则等控制事务具体行为的事务属性，这些事务属性可以通过XML配置或注解描述提供，也可以通过手工编程的方式设置。PlatformTransactionManager根据TransactionDefinition提供的事务属性配置信息，创建事务，并用TransactionStatus描述这个激活事务的状态。

1）Spring JDBC 和iBatis

基于数据源的数据管理器

<context:property-placeholder location="classpath:jdbc.properties"/>
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close"
          p:driverClassName="${jdbc.driverClassName}"
          p:url="${jdbc.url}"
          p:username="${jdbc.username}"
          p:password="${jdbc.password}"/>
     <bean id="transactionManager"
      class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
      p:dataSource-ref="dataSource"/>

2）JPA

JAP事务管理器配置

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
          p:dataSource-ref="dataSource"/>
    ...
<bean id="transactionManger" class="org.springframework.orm.jpa.JpaTransactionManager"
          p:entityManagerFacotry-ref="entityManagerFactory"/>

3）Hibernate

Hibernate3.0事务管理器配置

<bean id="sessionFactory"
     class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"
     p:dataSource-ref="dataSource"
     p:mappingResources="classpath:bbtForum.hbm.xml">
   <property name="hibernateProperties">
     <props>
       <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
       <prop key="hibernate.show_sql">true</prop>
       <prop key="hibernate.generate_statistics">true</prop>
     </props>
   </property>
</bean>

4）JTA

JTA事务管理器

<jee:jndi-lookup id="accountDs" jndi-name="java:comp/env/jdbc/account"/>
<jee:jndi-lookup id="orderDs" jndi-name="java:comp/env/jdbc/account"/>
<bean id="transactionManager"
     class="org.springframework.transaction.jta.JtaTransactionManager"/>

2、编程式事务管理

Spring事务管理提供了模板类org.springframework.transaction.support.TransactionTemplate，以满足一些特殊场合的需要。

package com.baobaotao.service;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallbackWithoutResult;
import org.springframework.transaction.support.TransactionTemplate;
import com.baobaotao.dao.ForumDao;
import com.baobaotao.domain.Forum;
public class ForumService1 {
    private ForumDao forumDao;
    //通过IoC注入
    private TransactionTemplate template;
    public void addForum(final Forum forum) {
        template.execute(new TransactionCallbackWithoutResult() {
            protected void doInTransactionWithoutResult(TransactionStatus status) {
                //需要在事务环境中执行的代码
                forumDao.addForum(forum);
            }
        });
    }
    public void setForumDao(ForumDao forumDao) {
        this.forumDao = forumDao;
    }
    public void setTemplate(TransactionTemplate template) {
        this.template = template;
    }    
}

3、使用XML配置声明式事务

Spring的声明式事务管理是通过Spring AOP实现的，通过事务的声明性信息，Spring负责将事务管理增强逻辑动态织入到业务方法相应连接点中。这些逻辑包括获取线程绑定资源、开始事务、提交/回滚事务、进行异常转换和处理等工作。

BbtForum接口：

package com.yyq.service;
import com.yyq.domain.Forum;
import com.yyq.domain.Topic;
public interface BbtForum {
    void addTopic(Topic topic) throws Exception;
    void updateForum(Forum forum);
    Forum getForum(int forumId);
    int getForumNum();
}

BbtForumImpl实现类：

package com.yyq.service.impl;
import com.yyq.dao.ForumDao;
import com.yyq.dao.PostDao;
import com.yyq.dao.TopicDao;
import com.yyq.domain.Forum;
import com.yyq.domain.Topic;
import com.yyq.service.BbtForum;
public class BbtForumImpl implements BbtForum {
    private ForumDao forumDao;
    private TopicDao topicDao;
    private PostDao postDao;
    public void addTopic(Topic topic) throws Exception {
        topicDao.addTopic(topic);
//        if(true) throw new PessimisticLockingFailureException("fail");
        postDao.addPost(topic.getPost());
    }
    public Forum getForum(int forumId) {
        return forumDao.getForum(forumId);
    }
    public void updateForum(Forum forum) {
        forumDao.updateForum(forum);
    }
    public int getForumNum() {
        return forumDao.getForumNum();
    }
    public void setForumDao(ForumDao forumDao) {
        this.forumDao = forumDao;
    }
    public void setPostDao(PostDao postDao) {
        this.postDao = postDao;
    }
    public void setTopicDao(TopicDao topicDao) {
        this.topicDao = topicDao;
    }
}

Dao和Datasource配置文件applicationContext-dao.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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close"
          p:driverClassName="${jdbc.driverClassName}"
          p:url="${jdbc.url}"
          p:username="${jdbc.username}"
          p:password="${jdbc.password}"/>
    <bean id="jdbcTemplate"
            class="org.springframework.jdbc.core.JdbcTemplate"
            p:dataSource-ref="dataSource"/>
    <bean id="abstracDao" abstract="true" p:jdbcTemplate-ref="jdbcTemplate"/>
    <bean id="forumDao" parent="abstracDao" class="com.yyq.dao.jdbc.ForumDaoImpl" />
    <bean id="postDao" parent="abstracDao" class="com.yyq.dao.jdbc.PostDaoImpl"/>
    <bean id="topicDao" parent="abstracDao" class="com.yyq.dao.jdbc.TopicDaoImpl"/>
</beans>

1）使用原始的TransactionProxyFactoryBean进行声明式事务配置：

<?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:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
    <!--导入Dao和DataSource的配置文件-->
    <import resource="applicationContext-dao.xml"/>
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--需要实施事务增强的目标业务Bean-->
    <bean id="bbtForumTarget" class="com.yyq.service.impl.BbtForumImpl"
          p:forumDao-ref="forumDao"
          p:topicDao-ref="topicDao"
          p:postDao-ref="postDao"/>
    <!--使用事务代理工程类为目标业务Bean提供事务增强-->
    <bean id="bbtForum" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"
          p:transactionManager-ref="txManager"
          p:target-ref="bbtForumTarget">
        <property name="transactionAttributes">
            <props>
                <prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
                <prop key="*">PROPAGATION_REQUIRED</prop>
            </props>
        </property>
    </bean>
</beans>

测试方法：

import com.yyq.domain.Post;
import com.yyq.domain.Topic;
import com.yyq.service.BbtForum;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestBbtForumPfb {
    public static void main(String[] args) throws Throwable{
        String configPath = "classpath:applicationContext-pfb.xml";
        ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath);
        BbtForum bbtForum = ctx.getBean("bbtForum",BbtForum.class);
        System.out.println("begin........");
        Topic topic = new Topic();
        topic.setTopicTitle("Title -pfb");
        Post post = new Post();
        post.setPostText("post content -pfb");
        topic.setPost(post);
        bbtForum.addTopic(topic);
        System.out.println("end........");
    }
}

2）基于tx/aop命名空间的配置：

<?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:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    <!--导入Dao和DataSource的配置文件-->
    <import resource="classpath:applicationContext-dao.xml"/>
    <!--声明事务管理器-->
    <bean id="txManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
          p:dataSource-ref="dataSource"/>
    <!--不再需要为了事务AOP增强的实施而改名换姓-->
    <bean id="bbtForum"
          class="com.yyq.service.impl.BbtForumImpl"
          p:forumDao-ref="forumDao"
          p:topicDao-ref="topicDao"
          p:postDao-ref="postDao"/>
    <!--使用强大的切点表达式语言轻松定义目标方法-->
    <aop:config>
        <!--通过aop定义事务增强切面-->
        <aop:pointcut id="serviceMethod" expression="execution(* com.yyq.service.*Forum.*(..))"/>
        <!--引用事务增强-->
        <aop:advisor pointcut-ref="serviceMethod" advice-ref="txAdvice"/>
    </aop:config>
    <!--事务增强-->
    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <!--事务属性定义-->
            <tx:method name="get*" read-only="false"/>
            <tx:method name="add*" rollback-for="PessimisticLockingFailureException"/>
            <tx:method name="update*"/>
        </tx:attributes>
    </tx:advice>
</beans>

测试方法：

import com.yyq.domain.Post;
import com.yyq.domain.Topic;
import com.yyq.service.BbtForum;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestBbtForumTx {
    public static void main(String[] args) throws Throwable{
        String configPath = "classpath:applicationContext-tx.xml";
        ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath);
        BbtForum bbtForum = ctx.getBean(BbtForum.class);
        System.out.println("begin........");
        Topic topic = new Topic();
        topic.setTopicTitle("Title Tx-");
        Post post = new Post();
        post.setPostText("post content -Tx");
        topic.setPost(post);
        bbtForum.addTopic(topic);
        System.out.println("end........");
    }
}

4、使用注解配置声明式事务

使用@Transaction注解声明事务，可以应用于接口定义和接口方法、类定义和类的public方法上。

使用@Transaction注解的业务类：

@Transactional
public class BbtForumImpl implements BbtForum {
    private ForumDao forumDao;
    private TopicDao topicDao;
    private PostDao postDao;
    public void addTopic(Topic topic) throws Exception {
        topicDao.addTopic(topic);
        //if(true) throw new PessimisticLockingFailureException("fail");
        postDao.addPost(topic.getPost());
    }
    public Forum getForum(int forumId) {
        return forumDao.getForum(forumId);
    }
    public void updateForum(Forum forum) {
        forumDao.updateForum(forum);
    }
   ....

applicationContext-anno.xml：使事务注解生效

<?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:p="http://www.springframework.org/schema/p"
       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">
    <import resource="classpath:applicationContext-dao.xml"/>
    <!--由于该Bean实现类标注了@Transaction，所以将会被注解驱动自动织入事务-->
    <bean id="bbtForum"
          class="com.yyq.service.impl.BbtForumImpl"
          p:forumDao-ref="forumDao"
          p:topicDao-ref="topicDao"
          p:postDao-ref="postDao"/>
    <bean id="txManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
          p:dataSource-ref="dataSource"/>
    <!--对标注@Transaction注解的Bean进行加工处理，以织入事务管理切面-->
    <tx:annotation-driven transaction-manager="txManager" proxy-target-class="true"/>
</beans>