JAVAEE框架之Spring事务

/**
     * 转账业务
     * @param sourceId
     * @param targetId
     * @param money
     */
    public void transfer(Integer sourceId, Integer targetId,Double money) {
        //1.根据id，查询转出账户
        Account source=accountDao.selectAccount(sourceId);
        //2.根据id,查询转入账户
        Account target=accountDao.selectAccount(targetId);
        //3.转出账户减钱
        source.setMoney(source.getMoney()-money);
        //4.转入账户加钱
        target.setMoney(target.getMoney()+money);
        //5.更新转出账户
        accountDao.updateAccount(source);
        //6.更新转入账户
        accountDao.updateAccount(target);
    }

ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        //2.获取Spring的bean
        AccountService accountService = (AccountService) ac.getBean("accountService");
        //3.2 测试转账业务
        accountService.transfer(1,2,1111.0);

package com.aaa.util;
import javax.sql.DataSource;
import java.sql.Connection;
/**
 * Created by 张晨光 on 2020/7/4 11:42
 * 连接的工具类，用于从数据源中获取连接，并且实现和线程的绑定
 */
public class ConnUtils {
    private ThreadLocal<Connection> threadLocal=new ThreadLocal<Connection>();
    private DataSource dataSource;
    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }
    /**
     * 获取线程上的连接
     * @return
     */
    public Connection getThreadConnection(){
        try {
            //1.从threadLocal获取本地链接对象
            Connection conn=threadLocal.get();
            //2.判断当前线程上是否有链接;
            if(conn==null){
                //3.从数据源中获取链接对象，存入threadLocal中
                conn=dataSource.getConnection();
                threadLocal.set(conn);
            }
            //4.返回当前线程上的链接;
            return conn;
        } catch (Exception e) {
           throw new RuntimeException(e);
        }
    }
    /**
     * 解绑连接对象和线程
     */
    public void removeConnection(){
        threadLocal.remove();
    }
}

package com.aaa.util;
import java.sql.SQLException;
/**
 * Created by 张晨光 on 2020/7/4 11:53
 */
public class TransactionManager {
    //调用连接管理类
    private ConnUtils connUtils;
    public void setConnUtils(ConnUtils connUtils) {
        this.connUtils = connUtils;
    }
    /**
     * 设置开始的时候自动提交事务为false,变为手动提交;
     */
    public void beginTransaction(){
        try {
            connUtils.getThreadConnection().setAutoCommit(false);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    /**
     * 自动提交事务
     */
    public void commit(){
        try {
            connUtils.getThreadConnection().commit();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    /**
     * 回滚事务
     */
    public void rollback(){
        try {
            connUtils.getThreadConnection().rollback();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    /**
     * 释放连接
     */
    public void release(){
        try {
            connUtils.getThreadConnection().rollback();
            connUtils.removeConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

<bean id="tx" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>
<tx:annotation-driven transaction-manager="tx"/>

@Service("accountService")
@Transactional
public class AccountServiceImpl implements AccountService