Spring 编程事物管理

除了Spring的DIST下的包外，加入：

commons-pool.jarcommons-dbcp.jarmysql-connector-java-5.1.5-bin.jar

 

这里使用的是mysql数据库，在test库内创建表：

DROP TABLE IF EXISTS `user`;CREATE TABLE `user` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `age` int(11) DEFAULT NULL,  `name` varchar(255) DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

编程式事物相对声明式事物有些繁琐，但是还是有其独到的优点。编程式的事物管理可以清楚的控制事务的边界，自行控制事物开始、撤销、超时、结束等，自由控制事物的颗粒度。
借用Spring MVC 入门示例http://cuisuqiang.iteye.com/blog/2042931的代码。这里直接在Action层直接做代码示例，并使用注解进行属性注入：

首先编辑applicationContext.xml，配置数据库连接属性：

<?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:mvc="http://www.springframework.org/schema/mvc"       xmlns:p="http://www.springframework.org/schema/p"       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/beanshttp://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsdhttp://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"><!-- 数据源 --><bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver" /><property name="url" value="jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=UTF-8" /><property name="username" value="root" /><property name="password" value="root" /></bean></beans>

 

Spring提供两种实现方式，使用PlatformTransactionManager或TransactionTemplate。
以下示例使用PlatformTransactionManager的实现类DataSourceTransactionManager来完成。

package test;import java.util.Date;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.sql.DataSource;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.datasource.DataSourceTransactionManager;import org.springframework.transaction.TransactionStatus;import org.springframework.transaction.support.DefaultTransactionDefinition;import org.springframework.web.bind.annotation.RequestMapping;// http://localhost:8080/spring/hello.do?user=[e-mail] class HelloController{private DataSourceTransactionManager transactionManager;private DefaultTransactionDefinition def;private JdbcTemplate jdbcTemplate;@SuppressWarnings("unused")// 使用注解注入属性@Autowiredprivate void setDataSource(DataSource dataSource){jdbcTemplate = new JdbcTemplate(dataSource);transactionManager = new DataSourceTransactionManager(dataSource);// 事物定义def = new DefaultTransactionDefinition();// 事物传播特性def.setPropagationBehavior(DefaultTransactionDefinition.PROPAGATION_REQUIRED);//def.setReadOnly(true); // 指定后会做一些优化操作，但是必须搭配传播特性，例如：PROPAGATION_REQUIRED,PROPAGATION_REQUIRES_NEW,PROPAGATION_NESTED//def.setTimeout(1000); // 合理的超时时间，有助于系统更加有效率}@SuppressWarnings("deprecation")@RequestMapping("/hello.do")public String hello(HttpServletRequest request,HttpServletResponse response){request.setAttribute("user", request.getParameter("user") + "-->" + new Date().toLocaleString());TransactionStatus status = transactionManager.getTransaction(def);try {jdbcTemplate.update(" update user set age=age+1; ");// 发生异常jdbcTemplate.update(" update user set age='test'; ");transactionManager.commit(status);} catch (Exception e) {transactionManager.rollback(status);}return "hello";}}

 

也可以使用TransactionTemplate来实现，它需要一个TransactionManager实例，代码如下：

package test;import java.util.Date;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.sql.DataSource;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.datasource.DataSourceTransactionManager;import org.springframework.transaction.TransactionStatus;import org.springframework.transaction.support.DefaultTransactionDefinition;import org.springframework.transaction.support.TransactionCallback;import org.springframework.transaction.support.TransactionTemplate;import org.springframework.web.bind.annotation.RequestMapping;@org.springframework.stereotype.Controllerpublic class HelloController{private DataSourceTransactionManager transactionManager;private DefaultTransactionDefinition def;private JdbcTemplate jdbcTemplate;@SuppressWarnings("unused")@Autowiredprivate void setDataSource(DataSource dataSource){jdbcTemplate = new JdbcTemplate(dataSource);transactionManager = new DataSourceTransactionManager(dataSource);def = new DefaultTransactionDefinition();def.setPropagationBehavior(DefaultTransactionDefinition.PROPAGATION_REQUIRED);}@SuppressWarnings({ "deprecation", "unchecked" })@RequestMapping("/hello.do")public String hello(HttpServletRequest request,HttpServletResponse response){request.setAttribute("user", request.getParameter("user") + "-->" + new Date().toLocaleString());TransactionTemplate transactionTemplate = new TransactionTemplate(transactionManager);Object obj = null;try {// 不需要返回值使用TransactionCallbackWithoutResultbackobj = transactionTemplate.execute(new TransactionCallback(){public Object doInTransaction(TransactionStatus arg0) {jdbcTemplate.update(" update user set age=age+1; ");// 发生异常jdbcTemplate.update(" update user set age='test'; ");return 1;}});} catch (Exception e) {e.printStackTrace();}System.out.println(obj);return "hello";}}

 

注意，不要再doInTransaction内做异常捕捉，否则无法控制事物。

 

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