记账本------2 | 易学教程

今天做了删除记账本。

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
    .a{
        margin-top: 20px;
    }
    .b{
        font-size: 20px;
        width: 160px;
        color: white;
        background-color: greenyellow;
    }
    .tb, td {
        border: 1px solid black;
        font-size: 22px;
    }
</style>
</head>
<body>
    <%
         Object message = request.getAttribute("message");
         if(message!=null && !"".equals(message)){
     
    %>
         <script type="text/javascript">
              alert("<%=request.getAttribute("message")%>");
         </script>
    <%} %>
    <div align="center">
        <h1 style="color: red;">账单信息列表</h1>
        <a href="index.jsp">返回主页</a>
        <table class="tb">
            <tr>
                <td>id</td>
                <td>账单类型</td>
                <td>年</td>
                <td>月</td>
                <td>日</td>
                <td>收入</td>
                <td>支出</td>
                <td align="center" colspan="2">操作</td>
            </tr>
            <c:forEach items="${bills}" var="xm">
                <tr>
                    <td>${xm.id}</td>
                    <td>${xm.type}</td>
                    <td>${xm.year}</td>
                    <td>${xm.month}</td>
                    <td>${xm.day}</td>
                    <td>${xm.income}</td>
                    <td>${xm.pay}</td>
                    <td><a href="BillServlet?method=getbillbyid&id=${xm.id}">删除</a></td>
                </tr>
            </c:forEach>
        </table>
    </div>
</body>
</html>

效果图------

<%@ 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>
<style>
    .a{
        margin-top: 20px;
    }
    .b{
        font-size: 20px;
        width: 160px;
        color: white;
        background-color: greenyellow;
    }
    .tb, td {
        border: 1px solid black;
        font-size: 22px;
    }
</style>
</head>
<body>
<%
         Object message = request.getAttribute("message");
         if(message!=null && !"".equals(message)){
     
    %>
         <script type="text/javascript">
              alert("<%=request.getAttribute("message")%>");
         </script>
    <%} %>

    <div align="center">
        <h1 style="color: red;">账单信息删除</h1>
        <a href="index.jsp">返回主页</a>
        <table class="tb">
            <tr>
                <td>账单类型</td>
                <td>${bill.type}</td>
            </tr>
            <tr>
                <td>年</td>
                <td>${bill.year}</td>
            </tr>
            <tr>
                <td>月</td>
                <td>${bill.month}</td>
            </tr>
            <tr>
                <td>日</td>
                <td>${bill.day}</td>
            </tr>
            <tr>
                <td>收入</td>
                <td>${bill.income}</td>
            </tr>
            <tr>
                <td>支出</td>
                <td>${bill.pay}</td>
            </tr>
        </table>
        <div class="a">
            <a onclick="return check()" href="BillServlet?method=delete&id=${bill.id}">删&nbsp;&nbsp;&nbsp;&nbsp;除</a>
        </div>
    </div>
    <script type="text/javascript">
        function check() {
            if (confirm("真的要删除吗？")){
                return true;
            }else{
                return false;
            }
        }
    </script>
</body>
</html>

dao类（结合记账本1 been1中都有）

public Bill getBillById(int id) {
        String sql = "select * from bill where id ='" + id + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        Bill bill = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                String type = rs.getString("type");
                String year = rs.getString("year");
                String month = rs.getString("month");
                String day = rs.getString("day");
                String income = rs.getString("income");
                String pay = rs.getString("pay");
                bill = new Bill(id, type, year, month,day,income,pay);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return bill;
    }
    
    
    public List<Bill> dellist() {
        String sql = "select * from bill";
        List<Bill> dellist = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;

        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            Bill bean = null;
            while (rs.next()) {
                int id = rs.getInt("id");
                String type2 = rs.getString("type");
                String year2 = rs.getString("year");
                String month2 = rs.getString("month");
                String day2 = rs.getString("day");
                String income2=rs.getString("income");
                String pay2=rs.getString("pay");
                bean = new Bill(id, type2, year2, month2,day2,income2,pay2);
                dellist.add(bean);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        
        return dellist;
    }

    public boolean delete (int id) {
        boolean f = false;
        String sql = "delete from bill where id='" + id + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        int a = 0;
        
        try {
            state = conn.createStatement();
            a = state.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }
        
        if (a > 0) {
            f = true;
        }
        return f;
        }

servlet类（基于记账本1）

package com.bill.servlet;
import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


import com.bill.dao.BillDao;
import com.bill.been.Bill;
@WebServlet("/BillServlet")
public class BillServlet extends HttpServlet{
    private static final long serialVersionUID = 1L;
    
    
    public BillServlet() {
        super();
    }
    BillDao dao=new BillDao();
    
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        String method = req.getParameter("method");
        if ("add".equals(method)) {
            add(req, resp);
        }else if ("getbillbyid".equals(method)) {
            getBillById(req, resp);
        }else if ("dellist".equals(method)) {
            dellist(req,resp);
        }else if ("delete".equals(method)) {
            delete(req,resp);
        }
    }
        private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
            // TODO Auto-generated method stub
            String type = req.getParameter("type");
            String year = req.getParameter("year");
            String month = req.getParameter("month");
            String day = req.getParameter("day");
            String income = req.getParameter("income");
            String pay = req.getParameter("pay");
            
            Bill bill=new Bill(type,year,month,day,income,pay);
            if(dao.add(bill)) {
                req.setAttribute("message", "保存成功!");
                req.getRequestDispatcher("add.jsp").forward(req, resp);
            }else {
                req.setAttribute("message", "保存失败!");
                req.getRequestDispatcher("add.jsp").forward(req, resp);
            }
        }
        
        
        private void getBillById(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
            req.setCharacterEncoding("utf-8");
            int id = Integer.parseInt(req.getParameter("id"));
            Bill bill = dao.getBillById(id);
            req.setAttribute("bill", bill);
            req.getRequestDispatcher("delete.jsp").forward(req,resp);
            
        }
        
        
        private void dellist(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
            req.setCharacterEncoding("utf-8");
            List<Bill> bills = dao.dellist();
            req.setAttribute("bills", bills);
            req.getRequestDispatcher("dellist.jsp").forward(req,resp);
            
        }
        
        
        private void delete(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{
            req.setCharacterEncoding("utf-8");
            int id = Integer.parseInt(req.getParameter("id"));
            dao.delete(id);
            req.setAttribute("message", "删除成功");
            req.getRequestDispatcher("index.jsp").forward(req,resp);
        }
        
}

来源：https://www.cnblogs.com/birdmmxx/p/10389634.html

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