spring分布式事务

分布式事务是指操作多个数据库之间的事务，spring的 org.springframework.transaction.jta.JtaTransactionManager，提供了分布式事务支持。如果使 用WAS的JTA支持，把它的属性改为WebSphere对应的TransactionManager。
    在tomcat下，是没有分布式事务的，不过可以借助于第三方软件jotm（Java Open Transaction Manager ）和AtomikosTransactionsEssentials实现，在spring中分布式事务是通过jta（jotm，atomikos）来进行 实现。
1、http://jotm.objectweb.org/
2、http://www.atomikos.com/Main/TransactionsEssentials

一、使用JOTM例子
(1)、Dao及实现

public   interface  GenericDao {

    public   int  save(String ds, String sql, Object[] obj)  throws  Exception;

    public   int  findRowCount(String ds, String sql);

}

 

public   class  GenericDaoImpl  implements  GenericDao{

    private   JdbcTemplate jdbcTemplateA;
    private   JdbcTemplate jdbcTemplateB;

    public   void  setJdbcTemplateA(JdbcTemplate jdbcTemplate) {
        this .jdbcTemplateA = jdbcTemplate;
    }

    public   void  setJdbcTemplateB(JdbcTemplate jdbcTemplate) {
        this .jdbcTemplateB = jdbcTemplate;
    }

    public   int  save(String ds, String sql, Object[] obj)  throws  Exception{
        if ( null  == ds ||  "" .equals(ds))  return  - 1 ;
        try {
            if (ds.equals( "A" )){
                return   this .jdbcTemplateA.update(sql, obj);
            }else {
                return   this .jdbcTemplateB.update(sql, obj);
            }
        }catch (Exception e){
            e.printStackTrace();
            throw   new  Exception( "执行"  + ds +  "数据库时失败！" );
        }
    }

    public   int  findRowCount(String ds, String sql) {
        if ( null  == ds ||  "" .equals(ds))  return  - 1 ;

        if (ds.equals( "A" )){
            return   this .jdbcTemplateA.queryForInt(sql);
        }else {
            return   this .jdbcTemplateB.queryForInt(sql);
        }
    }

}

(2)、Service及实现

public   interface  UserService {

    public   void  saveUser()  throws  Exception;

}

 

public   class  UserServiceImpl  implements  UserService{

    private  GenericDao genericDao;

    public   void  setGenericDao(GenericDao genericDao) {
        this .genericDao = genericDao;
    }

    public   void  saveUser()  throws  Exception {
        String userName = "user_"  + Math.round(Math.random()* 10000 );
        System.out.println(userName);

        StringBuilder sql = new  StringBuilder();
        sql.append(" insert into t_user(username, gender) values(?,?); " );
        Object[] objs = new  Object[]{userName, "1" };

        genericDao.save("A" , sql.toString(), objs);

        sql.delete(0 , sql.length());
        sql.append(" insert into t_user(name, sex) values(?,?); " );
        objs = new  Object[]{userName, "男的" }; //值超出范围
        genericDao.save("B" , sql.toString(), objs);
    }

}

(3)、applicationContext-jotm.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:context = "http://www.springframework.org/schema/context"
    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-2.5.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

    < description > springJTA  description >


    < bean   id = "propertyConfig"
            class = "org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" >
        < property   name = "locations" >
            < list >
                < value > classpath:jdbc.properties  value >
             list >
         property >
     bean >


    < bean   id = "jotm"   class = "org.springframework.transaction.jta.JotmFactoryBean" >
          < property   name = "defaultTimeout"   value = "500000" />
     bean >


    < bean   id = "jtaTransactionManager"   class = "org.springframework.transaction.jta.JtaTransactionManager" >
        < property   name = "userTransaction"   ref = "jotm"   />
     bean >


    < bean   id = "dataSourceA"   class = "org.enhydra.jdbc.pool.StandardXAPoolDataSource"   destroy-method = "shutdown" >
       < property   name = "dataSource" >
           < bean   class = "org.enhydra.jdbc.standard.StandardXADataSource"   destroy-method = "shutdown" >
               < property   name = "transactionManager"   ref = "jotm" />
               < property   name = "driverName"   value = "${jdbc.driver}" />
               < property   name = "url"   value = "${jdbc.url}" />
            bean >
        property >
       < property   name = "user"   value = "${jdbc.username}" />
       < property   name = "password"   value = "${jdbc.password}" />
     bean >


    < bean   id = "dataSourceB"   class = "org.enhydra.jdbc.pool.StandardXAPoolDataSource"   destroy-method = "shutdown" >
       < property   name = "dataSource" >
           < bean   class = "org.enhydra.jdbc.standard.StandardXADataSource"   destroy-method = "shutdown" >
               < property   name = "transactionManager"   ref = "jotm" />
               < property   name = "driverName"   value = "${jdbc2.driver}" />
               < property   name = "url"   value = "${jdbc2.url}" />
            bean >
        property >
       < property   name = "user"   value = "${jdbc2.username}" />
       < property   name = "password"   value = "${jdbc2.password}" />
     bean >

    < bean   id  =  "jdbcTemplateA"
         class  =  "org.springframework.jdbc.core.JdbcTemplate" >
         < property   name  =  "dataSource"   ref = "dataSourceA" />
     bean >

    < bean   id  =  "jdbcTemplateB"
         class  =  "org.springframework.jdbc.core.JdbcTemplate" >
         < property   name  =  "dataSource"   ref = "dataSourceB" />
     bean >


    < aop:config >
        < aop:pointcut   id = "pointCut"
                expression = "execution(* com.logcd.service..*.*(..))" />
        < aop:advisor   pointcut-ref = "pointCut"   advice-ref = "txAdvice" />

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


    < tx:advice   id = "txAdvice"   transaction-manager = "jtaTransactionManager" >
       < tx:attributes >
          < tx:method   name = "delete*"   rollback-for = "Exception" />
          < tx:method   name = "save*"   rollback-for = "Exception" />
          < tx:method   name = "update*"   rollback-for = "Exception" />
          < tx:method   name = "find*"   read-only = "true"   rollback-for = "Exception" />
        tx:attributes >
     tx:advice >

    < bean   id = "genericDao"
            class = "com.logcd.dao.impl.GenericDaoImpl"   autowire = "byName" >
     bean >

    < bean   id = "userService"
            class = "com.logcd.service.impl.UserServiceImpl"   autowire = "byName" >
     bean >

 beans >

(4)、测试

public   class  TestUserService{

    private   static  UserService userService;

    @BeforeClass
    public   static   void  init(){
        ApplicationContext app = new  ClassPathXmlApplicationContext( "applicationContext-jotm.xml" );
        userService = (UserService)app.getBean("userService" );
    }

    @Test
    public   void  save(){
        System.out.println("begin..." );
        try {
            userService.saveUser();
        }catch (Exception e){
            System.out.println(e.getMessage());
        }
        System.out.println("finish..." );
    }

}

二、关于使用atomikos实现
(1)、数据源配置

< bean   id = "dataSourceA"   class = "com.atomikos.jdbc.SimpleDataSourceBean"   init-method = "init"   destroy-method = "close" >
    < property   name = "uniqueResourceName" >
        < value > ${datasource.uniqueResourceName}  value >
     property >
    < property   name = "xaDataSourceClassName" >
        < value > ${database.driver_class}  value >
     property >
    < property   name = "xaDataSourceProperties" >
        < value > URL =${database.url}; user =${database.username}; password =${database.password}  value >
     property >
    < property   name = "exclusiveConnectionMode" >
        < value > ${connection.exclusive.mode}  value >
     property >
    < property   name = "connectionPoolSize" >
        < value > ${connection.pool.size}  value >
     property >
    < property   name = "connectionTimeout" >
        < value > ${connection.timeout}  value >
     property >
    < property   name = "validatingQuery" >
        < value > SELECT 1  value >
     property >
 bean >

(2)、事务配置

< 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 = "${transaction.timeout}" />
 bean >


< bean   id = "springTransactionManager"   class = "org.springframework.transaction.jta.JtaTransactionManager" >
    < property   name = "transactionManager"   ref = "atomikosTransactionManager" />
    < property   name = "userTransaction"   ref = "atomikosUserTransaction" />
 bean >


< aop:config >
    < aop:pointcut   id = "serviceOperation"    expression = "execution(* *..service*..*(..))" />
    < aop:advisor   pointcut-ref = "serviceOperation"   advice-ref = "txAdvice" />
 aop:config >


< tx:advice   id = "txAdvice"   transaction-manager = "springTransactionManager" >
    < tx:attributes >
        < tx:method   name = "*"   rollback-for = "Exception" />
     tx:attributes >
 tx:advice >