Spring学习——JDBC事务

spring 事务 主要是指jdbc事务

当一组事务执行完时,需要提交commit,才能在数据库中完成执行,
当一组事务中的某个错误时候,需要撤销回滚rollback()

当SQL执行报错时候,调用rollback函数,commit操作取消
当没有commit操作时候,数据库数据不会发生改变,rollback操作无效

1、JdbcTemplate.query/update ->  
2、PlatformTransactionManager.commit ->  
3、PlatformTransactionManager.rollback

1执行成功后,JdbcTemplate内数据对象发生改变,但数据库数据未发生改变
2执行成功后,JdbcTemplate内数据提交到数据库,数据库数据发生改变
3执行成功后,数据数据还原到commit之前

Beans.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" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd ">

   <!-- 初始化数据库配置文件 -->
   <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
      <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
      <property name="url" value="jdbc:mysql://localhost:3306/test"/>
      <property name="username" value="root"/>
      <property name="password" value=""/>
   </bean>
	
	<!-- 配置事务	 -->
   	<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      	<property name="dataSource"  ref="dataSource" />    
   	</bean>	
	
	<!-- 配置jdbc实现类 -->
   	<bean id="userJdbcTemplate" class="com.spring.transaction.demo.UserJdbcTemplate" >
   		<!-- 注入数据库配置文件 -->
   		<property name="dataSource"  ref="dataSource" /> 
   		<property name="transactionManager"  ref="transactionManager" />    
   	</bean>
   
   
</beans>

核心配置类

package com.spring.transaction.demo;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.DefaultTransactionDefinition;

public class UserJdbcTemplate{

	private JdbcTemplate jdbcTemplate;
	private DataSource dataSource;
	private PlatformTransactionManager ptm;
	
	public void setDataSource(DataSource dataSource) {
		this.dataSource = dataSource;
		this.jdbcTemplate = new JdbcTemplate(dataSource);
	}
	
	public void setTransactionManager(PlatformTransactionManager ptm){
		this.ptm = ptm;
	}
	
	public void update(int id){
		TransactionDefinition def = new DefaultTransactionDefinition();
		TransactionStatus status = ptm.getTransaction(def);
		try {
			String sql = "insert into user(id,username,password) values("+id+",'lg','123456')";
			System.out.println("sql执行:"+sql);
			jdbcTemplate.update(sql);
			
			sql = "insert into user(id,username,password) values("+(id-1)+",'zdj','123456')";
			System.out.println("sql执行:"+sql);
			jdbcTemplate.update(sql);
			
			sql = "update user set username='zh' where id = 2";
			System.out.println("sql执行:"+sql);
			jdbcTemplate.update(sql);
			
			ptm.commit(status);
		} catch (DataAccessException e) {
			System.out.println("回滚");
			ptm.rollback(status);
			e.printStackTrace();
		}
	}
	
	public List<UserPO> queryAll(){
		String sql = "select * from user";
		List<Map<String, Object>> mapList = jdbcTemplate.queryForList(sql);
		List<UserPO> list = new ArrayList();
		for (int i = 0; i < mapList.size(); i++) {
			UserPO user = new UserPO();
			user.setId((Integer)mapList.get(i).get("id"));
			user.setUsername(mapList.get(i).get("username").toString());
			user.setPassword(mapList.get(i).get("password").toString());
			list.add(user);
		}
		return list;
	}
}

SpringMain

package com.spring.transaction.demo;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringMain {
	public static void main(String[] args){
		ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
		UserJdbcTemplate ujt = (UserJdbcTemplate) context.getBean("userJdbcTemplate");
		System.out.println("--------第一次查询数据库-----------");
		System.out.println(ujt.queryAll().toString());
		
		System.out.println("---------正常执行-----------");
		ujt.update(2);
		System.out.println("--------第二次查询数据库-----------");
		System.out.println(ujt.queryAll().toString());
		
		System.out.println("---------错误执行-----------");
		ujt.update(3);
		System.out.println("--------第二次查询数据库-----------");
		System.out.println(ujt.queryAll().toString());
		
	}
}