账户转账演示事务

package utsc.java.jdbc.DBUtil;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/**
 * 重点三行代码
 *      conn.setAutoCommit(false);
 *      conn.commit();
 *      conn.rollback();
 */

public class JDBCTest11 {
    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            //1.注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            //2.获取连接
            conn= DriverManager.getConnection("jdbc:mysql://localhost:3306/imooc","root","123456");
            //将自动提交机制设置为手动提交
            conn.setAutoCommit(false);//开启事务
            //3.获取预编译的数据库操作对象
            String sql = "update t_act set balance = ? where actno = ?";
            ps = conn.prepareStatement(sql);
            //给？传值
            ps.setDouble(1,10000);
            ps.setInt(2,111);
            int count = ps.executeUpdate();



            //给？传值
            ps.setDouble(1,10000);
            ps.setInt(2,222);
             count += ps.executeUpdate();

            System.out.println(count == 2 ? "转账成功" : "转账失败");

            //程序能够走到这里说明以上程序没有异常，事务结束，手动提交数据
            //提交事务
            conn.commit();



        } catch (ClassNotFoundException | SQLException e) {
            //回滚事务
            if (conn !=null){
                try {
                    conn.rollback();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
            e.printStackTrace();
        }finally {
            //6.释放资源
            if (ps != null){
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }if (conn != null){
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}