Spring 编程事物管理

除了Spring的DIST下的包外，加入：

commons-pool.jar
commons-dbcp.jar
mysql-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，*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/beans
			http://www.springframework.org/schema/beans/spring-beans-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/aop 
			http://www.springframework.org/schema/aop/spring-aop-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/mvc 
			http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
			http://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=java
@org.springframework.stereotype.Controller
public class HelloController{
	private DataSourceTransactionManager transactionManager;
	private DefaultTransactionDefinition def;
	private JdbcTemplate jdbcTemplate;
	@SuppressWarnings("unused")
	// 使用注解注入属性
	@Autowired
	private 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.Controller
public class HelloController{
	private DataSourceTransactionManager transactionManager;
	private DefaultTransactionDefinition def;
	private JdbcTemplate jdbcTemplate;
	@SuppressWarnings("unused")
	@Autowired
	private 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TransactionCallbackWithoutResultback
			obj = 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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