Spring3.X 分布式事务

1.为什么要组建多数据源?    一个系统中存在多个数据库读写操作,如Oralce+MySql......等 2.为什么要组建分布式事务?    在同一个系统,同一个事务中对不同数据库进行写操作时,如若一个失败,那么应该对多个数据库进行回滚操作,否则应该全部提交. 3.分布式事务有哪些?    在Spring 2.5中可以采用jta,在Spring3.X中则已经不对其提供支持,但可以使用atomikos. 4.需要提供哪些jar包支持?   6个必须的jar包,可以通过maven下载  atomikos-util-3.9.3.jar  jta-1.1.jar transactions-3.9.3.jar transactions-api-3.9.3.jar  transactions-jdbc-3.9.3.jar  transactions-jta-3.9.3.jar 5.Spring 配置如何配置? 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:aop= "http://www.springframework.org/schema/aop"      xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"      xmlns:mvc="http://www.springframework.org/schema/mvc"      xsi:schemaLocation="        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd        http://www.springframework.org/schema/mvc        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">        <context:annotation-config />      <context:component-scan base-package ="com.cn" />                        <bean id ="oracleDS" class= "com.atomikos.jdbc.AtomikosDataSourceBean" init-method= "init" destroy-method ="close">         <description >oracle xa datasource description >         <property name ="uniqueResourceName">             <value >oracle_ds value >         property >         <property name ="xaDataSourceClassName">             <value> oracle.jdbc.xa.client.OracleXADataSourcevalue >         property >         <property name ="xaProperties">             <props >                 <prop key ="user">dongruan prop>                 <prop key ="password">dongruan prop>                 <prop key= "URL">jdbc:oracle:thin:@100.100.100.30:1521: orcl prop>             props >         property >         <property name ="testQuery">         <value >select 1 from dual value >         property >     bean >           <bean id ="mysqlDS" class= "com.atomikos.jdbc.AtomikosDataSourceBean" init-method= "init" destroy-method ="close">         <description >mysql xa datasource description>         <property name ="uniqueResourceName">             <value >mysql_ds value >         property >         <property name ="xaDataSourceClassName">             <value> com.mysql.jdbc.jdbc2.optional.MysqlXADataSourcevalue >         property >         <property name ="xaProperties">             <props >                 <prop key ="user">datapre prop>                 <prop key ="password">flow2012 prop>                 <prop key= "URL">jdbc:mysql://100.100.100.48:3306/ dataprepare prop>             props >         property >         <property name ="testQuery">         <value >select 1 value >         property >     bean >                 <bean id ="oracleSqlSession" class= "org.mybatis.spring.SqlSessionFactoryBean" >             <property name ="dataSource" ref="oracleDS" />             <property name ="mapperLocations" value= "classpath:com/cn/oraclemapper/*Mapper.xml" />             <property name ="typeAliasesPackage" value= "com.cn.oraclepo" />      bean >      <bean id ="oracleMapperScanner" class= "org.mybatis.spring.mapper.MapperScannerConfigurer" >             <property name ="sqlSessionFactoryBeanName" value= "oracleSqlSession" />             <property name ="basePackage" value= "com.cn.oraclemapper" />      bean >              <bean id ="mysqlSqlSessionFactory" class= "org.mybatis.spring.SqlSessionFactoryBean" >             <property name ="dataSource" ref="mysqlDS" />             <property name ="mapperLocations" value= "classpath:com/cn/mapper/*Mapper.xml" />             <property name ="typeAliasesPackage" value= "com.cn.po" />      bean >      <bean id ="mysqlMapperScanner" class= "org.mybatis.spring.mapper.MapperScannerConfigurer" >             <property name ="sqlSessionFactoryBeanName" value= "mysqlSqlSessionFactory" > property>             <property name ="basePackage" value="com.cn.mapper" />      bean >                  <bean id ="atomikosUserTransaction" class= "com.atomikos.icatch.jta.UserTransactionImp" >             <description >UserTransactionImp description >             <property name ="transactionTimeout" value= "300" />      bean >      <bean id ="atomikosTransactionManager" class= "com.atomikos.icatch.jta.UserTransactionManager" init-method= "init" destroy-method ="close">             <description >UserTransactionManager description >             <property name ="forceShutdown">                  <value >true value >             property >      bean >      <bean id ="springTransactionManager" class= "org.springframework.transaction.jta.JtaTransactionManager" >             <description >JtaTransactionManager description >             <property name ="transactionManager">                  <ref bean ="atomikosTransactionManager" />             property >             <property name ="userTransaction">                  <ref bean ="atomikosUserTransaction" />             property >             <property name ="allowCustomIsolationLevels" value= "true" />              bean >      <bean id ="atomikosTransactionProxy" class= "org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract ="true">           <property name ="transactionManager">                <ref bean ="springTransactionManager" />           property >           <property name ="transactionAttributes">                <props >                 <prop key= "*">PROPAGATION_REQUIRED,-Exception prop >                props >           property >      bean >                <tx:annotation-driven transaction-manager="springTransactionManager" /> beans>  6.测试代码如下: package com.cn.main; import java.io.UnsupportedEncodingException; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.cn.testService;   public class main {      public static void main(String[] args) throws UnsupportedEncodingException {            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("DataSource.xml" );                       testService service = context.getBean(testService.class );            service.test();      } } 7.Service类: package com.cn; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import com.cn.mapper.SendPreMapper; import com.cn.oraclemapper.AirwayPointFlowMapper; import com.cn.oraclepo.AirwayPointFlow; import com.cn.po.SendPreWithBLOBs; @Service public class testService {      @Autowired      public SendPreMapper mysqlMapper;      @Autowired      public AirwayPointFlowMapper oracleMapper;        @Transactional      public void test() {           SendPreWithBLOBs pre = new SendPreWithBLOBs();           pre.setId(123457);            mysqlMapper.insert(pre);             AirwayPointFlow air = new AirwayPointFlow();           air.setId( "11111111112");            oracleMapper.insert(air);      } }