使用Atomikos Transactions Essentials实现多数据源JTA分布式事务--转载

原文：http://www.ite/topic/122700

9.17 update:使用NonXADataSourceBean. Mysql在5.0版本和Connecter/J5.0版本后提供了XADatasource支持，如果使用了支持XADatasouce版本，可以参考2楼补充.

最近做的project中遇到要将数据库中的表分布到两台不同的服务器上的Mysql5.0中，project主要使用spring+ibatis。因此需要JTA的支持，但是tomcat不支持，所以就搜索开源的JTA实现。
最开始使用的是JOTM，但是使用中不能自动rollback，无论什么情况都commit。然后看到infoq上一篇文章提到Atomikos Transactions Essentials，Atomikos Transactions Essentials 3.0是Atomikos 开发的核心事务引擎，支持JDBC 以及JMS 的JTA/XA 事务。易于部署，轻量级，同时支持JDBC 以及JMS 。
Atomikos Transactions Essentials现在的版本是3.1.7,可以在http://www.atomikos.com/Main/TransactionsEssentialsDownloadForm 下载，在发布包里的examples文件夹下面有些例子，非常实用，我在使用中参考里面的例子很容易配置成功。先将发布包里面dist目录下的atomikos-util.jar，transactions.jar，transactions-api.jar，transactions-jta.jar copy到项目lib里面， 如果使用hibernate则需要将另外两个hibernate相关的jar页copy到项目里面，spring配置文件如下:

xml 代码

<!-- 第一个数据库 -->

< bean id = "dataSource" class = "com.atomikos.jdbc.SimpleDataSourceBean" init-method = "init" destroy-method = "close" >

< property name = "uniqueResourceName" >

< value > mysql/main </ value >

</ property >

< property name = "xaDataSourceClassName" >

<!-- 使用Mysql XADataSource(mysql>=5.0, Connector/J>=5.0才可以支持XADatasource)-->

< value > com.mysql.jdbc.jdbc2.optional.MysqlXADataSource </ value >

</ property >

< property name = "xaDataSourceProperties" >

< value > URL =${jdbc.url}; user =${jdbc.username}; password =${jdbc.password} </ value >

</ property >

< property name = "exclusiveConnectionMode" >

< value > true </ value >

</ property >

< property name = "connectionPoolSize" >

< value > 3 </ value >

</ property >

< property name = "validatingQuery" >

< value > SELECT 1 </ value >

</ property >

</ bean >

<!-- 第二个数据库 -->

< bean id = "dataSourceB" class = "com.atomikos.jdbc.SimpleDataSourceBean" init-method = "init" destroy-method = "close" >

< property name = "uniqueResourceName" >

< value > mysql/news </ value >

</ property >

< property name = "xaDataSourceClassName" >

<!-- 使用Mysql XADataSource(mysql>=5.0, Connector/J>=5.0才可以支持XADatasource)-->

< value > com.mysql.jdbc.jdbc2.optional.MysqlXADataSource </ value >

</ property >

< property name = "xaDataSourceProperties" >

< value > URL =${jdbc.url.b}; user =${jdbc.username.b}; password =${jdbc.password.b} </ value >

</ property >

< property name = "exclusiveConnectionMode" >

< value > true </ value >

</ property >

< property name = "connectionPoolSize" >

< value > 3 </ value >

</ property >

< property name = "validatingQuery" >

< value > SELECT 1 </ value >

</ property >

</ bean >

< bean id = "lobHandler" class = "org.springframework.jdbc.support.lob.DefaultLobHandler" />

<!-- 第一个数据库的sqlMapClient -->

< bean id = "sqlMapClient" class = "org.springframework.orm.ibatis.SqlMapClientFactoryBean" >

< property name = "configLocation" >

<!-- 包含第一个数据库表的map -->

< value > classpath:/sqlmap-config.xml </ value >

</ property >

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

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

</ bean >

<!-- 第二个数据库的sqlMapClient -->

< bean id = "sqlMapClientB" class = "org.springframework.orm.ibatis.SqlMapClientFactoryBean" >

< property name = "configLocation" >

<!-- 包含第一个数据库表的map -->

< value > classpath:/sqlmap-configb.xml </ value >

</ property >

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

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

</ bean >

<!-- Construct Atomikos UserTransactionManager, needed to configure Spring -->

< bean id = "atomikosTransactionManager" class = "com.atomikos.icatch.jta.UserTransactionManager" init-method = "init"

destroy-method = "close" >

<!-- when close is called, should we force transactions to terminate or not? -->

< property name = "forceShutdown" >

< value > true </ value >

</ property >

</ bean >

<!-- Also use Atomikos UserTransactionImp, needed to configure Spring -->

< bean id = "atomikosUserTransaction" class = "com.atomikos.icatch.jta.UserTransactionImp" >

< property name = "transactionTimeout" value = "240" />

</ bean >

<!-- Configure the Spring framework to use JTA transactions from Atomikos -->

< bean id = "transactionManager" class = "org.springframework.transaction.jta.JtaTransactionManager" >

< property name = "transactionManager" >

< ref bean = "atomikosTransactionManager" />

</ property >

< property name = "userTransaction" >

< ref bean = "atomikosUserTransaction" />

</ property >

</ bean >

事务的配置, 使用了spring2.0的语法，所以将namesapce也帖出来了.

xml 代码

<? 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/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"

default-autowire = "byName" default-lazy-init = "true" >

<!-- 支持 @AspectJ 标记-->

< aop:aspectj-autoproxy />

< aop:config proxy-target-class = "true" >

< aop:advisor pointcut = "execution(* *Facade.*(..))" advice-ref = "txAdvice" />

< aop:advisor pointcut = "execution(* *Manager.*(..))" advice-ref = "txAdvice" />

</ aop:config >

< tx:advice id = "txAdvice" >

< tx:attributes >

< tx:method name = "get*" read-only = "true" />

< tx:method name = "find*" read-only = "true" />

< tx:method name = "has*" read-only = "true" />

< tx:method name = "locate*" read-only = "true" />

< tx:method name = "*" />

</ tx:attributes >

</ tx:advice >

</ beans >

这样配置以后就可以使用分布式事务，测试中出现异常时事务也自动提交。和JOTM相比Atomikos Transactions Essentials更加稳定，它原来是商业项目，现在开源了。象mysql一样卖服务支持的。而且论坛页比较活跃，有问题很快可以解决。