java连接Mysql，实现简单的事务修改

import java.sql.*;
import java.util.Scanner;

public class jdbc_test {

    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        Connection conn=null;
        PreparedStatement pstmt1=null;
        PreparedStatement pstmt2=null;
        try {
            //获取连接
            conn=JDBCUtils.getConnection();
            //开启事务
            conn.setAutoCommit(false);
            //定义sql语句
            String sql1="update account set balance=balance- ? where id=?";
            String sql2="update account set balance=balance+ ? where id=?";
            //获取执行sql对象
            pstmt1=conn.prepareStatement(sql1);
            pstmt2=conn.prepareStatement(sql2);
            //设置参数
            pstmt1.setDouble(1,500);
            pstmt1.setInt(2,1);
            pstmt2.setDouble(1,500);
            pstmt2.setInt(2,2);
            //执行sql
            pstmt1.executeUpdate();
            //手动制造异常
            //int i=3/0;
            pstmt2.executeUpdate();
            //提交事务
            conn.commit();

        }catch (Exception e){
            //事务回滚
            try{
                if(conn!=null){
                    conn.rollback();
                }
            }catch (SQLException e1){
                e1.printStackTrace();
            }
            e.printStackTrace();
        }finally {
            JDBCUtils.close(pstmt1,conn);
            JDBCUtils.close(pstmt2,conn);
        }

    }
 }