前言

Atomikos 是一个为Java平台提供增值服务的并且开源类事务管理器，主要用于处理跨数据库事务，比如某个指令在A库和B库都有写操作，业务上要求A库和B库的写操作要具有原子性，这时候就可以用到atomikos。笔者这里整合了一个spring和atomikos的demo,并且通过案例演示说明atomikos的作用。

准备工作

开发工具：idea

数据库：mysql , oracle

正文

源码地址：https://github.com/qw870602/atomikos

演示原理：通过在两个库的写操作之间人为制造异常来观察数据库是否回滚

演示步骤：1.正常写操作，观察数据库值的变化情况

2.在写操作语句之间制造异常，观察数据库值的变化情况

项目结构

从web.xml中可以知道，容器只加载了appliactionContext.xml，剩下的配置文件除了database.properties外都是无用文件，所以大家如果要在项目中配置的话，仅需要把appliactionContext.xml中关于atomikos的部分新增到自己项目中就OK了

appliactionContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
        xmlns="http://www.springframework.org/schema/beans"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:p="http://www.springframework.org/schema/p"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        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/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
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
    <!-- 引入数据源信息的properties属性文件 -->
    <context:property-placeholder location="classpath:database.properties" />
    <!-- XA方式 -->
    <!-- MYSQL数据库配置 -->
    <bean id="mysqlDataSource" class="com.atomikos.jdbc.AtomikosDataSourceBean" destroy-method="close">
        <property name="uniqueResourceName" value="dataSource1"/>
        <property name="xaDataSourceClassName" value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource"/>
        <property name="xaProperties">
            <props>
                <prop key="URL">${mysql.qa.db.url}</prop>
                <prop key="user">${mysql.qa.db.user}</prop>
                <prop key="password">${mysql.qa.db.password}</prop>
            </props>
        </property>
        <property name="minPoolSize" value="10" />
        <property name="maxPoolSize" value="100" />
        <property name="borrowConnectionTimeout" value="30" />
        <property name="maintenanceInterval" value="60" />
    </bean>

    <!-- ORACLE数据库配置 -->
    <bean id="oracleDataSource" class="com.atomikos.jdbc.AtomikosDataSourceBean" destroy-method="close">
        <property name="uniqueResourceName" value="dataSource2"/>
        <property name="xaDataSourceClassName" value="oracle.jdbc.xa.client.OracleXADataSource" />
        <property name="xaProperties">
            <props>
                <prop key="URL">${oracle.qa.db.url}</prop>
                <prop key="user">${oracle.qa.db.user}</prop>
                <prop key="password">${oracle.qa.db.password}</prop>
            </props>
        </property>
        <property name="minPoolSize" value="10" />
        <property name="maxPoolSize" value="100" />
        <property name="borrowConnectionTimeout" value="30" />
        <property name="maintenanceInterval" value="60" />
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--<property name="configLocation" value="classpath:mybatis-config-mysql.xml" />-->
        <property name="dataSource" ref="mysqlDataSource" />
        <property name="mapperLocations" >
            <list>
                <value>classpath*:/dao/*.xml</value>
            </list>
        </property>
    </bean>
    <bean id="sqlSessionFactoryOracle" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--<property name="configLocation" value="classpath:mybatis-config.xml" />-->
        <property name="dataSource" ref="oracleDataSource" />
        <property name="mapperLocations" >
            <list>
                <value>classpath*:/daodev/*.xml</value>
            </list>
        </property>
    </bean>

    <!-- MyBatis为不同的mapper注入sqlSessionFactory -->
    <bean id="mysqlTransactionTestDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
        <property name="mapperInterface" value="com.xy.dao.MysqlTransactionTestDao" />
    </bean>
    <bean id="transactionTestDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="sqlSessionFactoryOracle" />
        <property name="mapperInterface" value="com.xy.dao.TransactionTestDao" />
    </bean>

    <!-- 分布式事务 -->
    <bean id="atomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager" init-method="init" destroy-method="close">
        <property name="forceShutdown" value="true"/>
    </bean>
    <bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">
        <property name="transactionTimeout" value="300"/>
    </bean>
    <bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
        <property name="transactionManager" ref="atomikosTransactionManager"/>
        <property name="userTransaction" ref="atomikosUserTransaction"/>
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager"/>
    <context:annotation-config/>
    <!--&lt;!&ndash; 自动扫描controller包下的所有类，如果@Controller注入为bean &ndash;&gt;-->
    <!--&lt;!&ndash;事务管理层&ndash;&gt;-->
    <context:component-scan base-package="com.xy" />

    <!-- 注册拦截器 -->
    <!--<mvc:interceptors>
        <bean class="com.springmybatis.system.interceptor.MyInterceptor" />
    </mvc:interceptors>-->
</beans>

适用JUnit4进行单元测试

package com.xy.controller;

import com.xy.daodev.TransactionTestService;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests;

@ContextConfiguration(locations = {"classpath:applicationContext.xml"})
public class TransactionTestMain extends AbstractJUnit4SpringContextTests {
   @Autowired
 private TransactionTestService transactionTestService;
 
 /**
  * 在同一事务有多个数据源
  */
 @Test
 public void multipleDataSource2() {
  transactionTestService.updateMultipleDataSource("1","1", 100L,"1.6");
 }
}

业务实现，当前没有异常操作

@Service
public class TransactionTestServiceImpl implements TransactionTestService {
   @Autowired
 @Qualifier("mysqlTransactionTestDao")
 private MysqlTransactionTestDao mysqlTransactionTestDao;
 
 @Autowired
 @Qualifier("transactionTestDao")
 private TransactionTestDao transactionTestDao;
 
 /**
  * 在同一事务有多个数据源
  */
 @Override
 @Transactional
 public void updateMultipleDataSource(String deUserId, String inUserid, long money,String str) {
  // 账户1转出操作
  mysqlTransactionTestDao.decreaseMoney(deUserId, money);
    //Integer.parseInt(str);
  // 账户2转入操作
  transactionTestDao.increaseMoney(inUserid, money);
  
 }  

}

mysql模拟金额转出，oracle模拟金额转入

<update id="decreaseMoney" parameterType="java.util.Map">
    UPDATE fx1 SET amount=amount - #{1,jdbcType=BIGINT} WHERE id=#{0,jdbcType=VARCHAR}
</update>

<update id="increaseMoney">
    UPDATE fx1 SET amount=amount + #{1,jdbcType=BIGINT} WHERE id=#{0,jdbcType=VARCHAR}
</update>

mysql初始金额

oracle初始金额

执行正常操作

mysql当前金额

oracle当前金额

将被屏蔽的制造异常的代码打开

public void updateMultipleDataSource(String deUserId, String inUserid, long money,String str) {
 // 账户1转出操作
 mysqlTransactionTestDao.decreaseMoney(deUserId, money);
   Integer.parseInt("skg");
 // 账户2转入操作
 transactionTestDao.increaseMoney(inUserid, money);
}

发现mysql和oracle的当前金额都没有变化，说明事务回滚成功，查看日志

发现控制台打印出了异常信息，并且atomikos调用了rollback()方法，从日志也证实了回滚成功。