JDBC事务（二）转账示例

示例采用三层框架

web层：

package cn.sasa.web;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import cn.sasa.service.TransferService;

public class TransferServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        String outAccount = request.getParameter("outAccount");

        String inAccount = request.getParameter("inAccount");

        double money = Double.parseDouble(request.getParameter("money"));

        TransferService tran = new TransferService();

        boolean flag =  tran.doTran(outAccount, inAccount, money);

        if(flag) {

            response.getWriter().write("ok");

        }else {

            response.getWriter().write("no");

        }

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        doGet(request, response);

    }

}

service层：

package cn.sasa.service;

import java.sql.Connection;

import java.sql.SQLException;

import cn.sasa.dao.TransferDao;

import cn.sasa.util.C3P0Utils;

public class TransferService {

    public boolean doTran(String outAccount, String inAccount, double money) {

        Connection conn = C3P0Utils.getConnection();

        boolean flag = true;

        try {

            conn.setAutoCommit(false);

            TransferDao tran = new TransferDao();

            int rs1 = tran.doOutAccount(conn, outAccount, money);

            int rs2 = tran.doInAccount(conn, inAccount, money);

            if(rs1<=0 || rs2<=0) {

                conn.rollback();

                flag=false;

            }

        } catch (Exception e) {

            flag = false;

            try {

                conn.rollback();

            } catch (SQLException e1) {

                // TODO Auto-generated catch block

                e1.printStackTrace();

            }

            e.printStackTrace();

        }finally {

            try {

                conn.commit();

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

        return flag;

    }

}

dao层：

package cn.sasa.dao;

import java.sql.Connection;

import java.sql.SQLException;

import org.apache.commons.dbutils.QueryRunner;

public class TransferDao {

    //资金转出

    public int doOutAccount(Connection conn, String outAccount, double money) throws SQLException {

        QueryRunner runner = new QueryRunner();

        String sql = "update account set money=money-? where name=?";

        int rs = runner.update(conn, sql, money,outAccount);

        return rs;

    }

    //资金转入

    public int doInAccount(Connection conn, String inAccount, double money) throws SQLException {

        QueryRunner runner = new QueryRunner();

        String sql = "update account set money=money+? where name=?";

        int rs = runner.update(conn, sql, money,inAccount);

        return rs;

    }

}

客户端jsp页：

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<!DOCTYPE html>

<html>

<head>

<meta charset="UTF-8">

<title>Insert title here</title>

</head>

<body>

    <form action="${pageContext.servletContext.contextPath}/TransferServlet" method="post">

        转出账户：<input type="text" name="outAccount" value=""/><br/>

        转入账户：<input type="text" name="inAccount" value=""/><br/>

        转账金额：<input type="text" name="money" value=""/><br>

        <input type="submit" value="确定">

    </form>

</body>

</html>

事务的注意事项：

手动开启事务都用 conn.setAutoCommit(false);

要用同一个conn控制事务。

秒客网

JDBC事务（二）转账示例

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