【JavaWeb開發】JavaWeb之MVC中真分頁的實現

分頁分爲真分頁和假分頁；

假分頁就是還是一次性查到所有數據，但通過前端的一些技巧看起來像是在分頁，對數據庫一樣很有壓力；

真分頁就是利用limit在查詢的時候的限制，每次查的就是這麼多數據；

本章講述的是在純MVC環境下，在條件查詢的情況下添加分頁。例子就是一個簡單的商品增刪查改。

首先介紹一下具體的層次

1.構建分頁實體類Page（使用了泛型，可以在多種對象中複用）

由於總條數一定是要去數據庫每次都查一遍的，那麼就在調setTotalPage的時候一次性計算完page的所有屬性。

package org.hc.homework.entity;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

//分頁
public class Page<T> implements Serializable {
    private static final long serialVersionUID = -4147209130619898593L;

    private int pageSize;//每頁的條數,也是limit讀取的個數
    private int currentPage;//當前頁號
    private int totalCount;//總條數——從數據庫中拿到
    private int start;//數據庫limit開始條數 = (currentPage-1)*pageSize
    private int totalPage;//總頁數 = 總條數/每頁的條數

    private List<T> lists=new ArrayList<>();//用於存儲數據庫查出的數據


    public List<T> getLists() {
        return lists;
    }

    public void setLists(List<T> lists) {
        this.lists = lists;
    }

    public int getPageSize() {
        return pageSize;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    public int getCurrentPage() {
        return currentPage;
    }

    public void setCurrentPage(int currentPage) {
        if (currentPage <= 0) {
            this.currentPage = 1;
        } else {
            this.currentPage = currentPage;
        }
    }

    public int getTotalCount() {
        return totalCount;
    }

    public void setTotalCount(int totalCount) {//在set總條數的時候將所有數據全部計算完成
        this.totalCount = totalCount;
        //總頁數的計算
        if (totalCount / pageSize <1) {
            this.totalPage = 1;
        } else if (totalCount % pageSize == 0) {
            this.totalPage = totalCount / pageSize;
        } else {
            this.totalPage = totalCount / pageSize + 1;
        }
        //limit開始序號的計算
        this.start = (currentPage - 1) * pageSize;
    }

    public int getTotalPage() {
        return totalPage;
    }

    public int getStart() {
        return start;
    }

}

1.1 實體類Shop

package org.hc.homework.entity;

import java.io.Serializable;
//數據庫具體屬性
/* `no` varchar(50) NOT NULL,
  `name` varchar(50) NOT NULL,
  `time` varchar(50) NOT NULL,
  `address` varchar(50) NOT NULL,
  `type` varchar(50) NOT NULL,*/
public class Shop implements Serializable {
    private static final long serialVersionUID = -3998521295785926249L;
    private String no;
    private String name;
    private String time;
    private String address;
    private String type;

    public Shop(String no, String name, String time, String address, String type) {
        this.no = no;
        this.name = name;
        this.time = time;
        this.address = address;
        this.type = type;
    }
    public Shop(){}

    public String getNo() {
        return no;
    }

    public void setNo(String no) {
        this.no = no;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}

2.MYSQL連接工具類 JdbcUtil （根據實際情況更改）

package org.hc.homework.utils;


import java.sql.*;

public class JdbcUtil {
    //數據庫驅動類
    public static final String DRIVER = "com.mysql.cj.jdbc.Driver";
    //數據庫的連接地址
    public static final String URL = "jdbc:mysql://localhost:3306/javawebjdbcdemo?serverTimezone=UTC";
    //賬號
    public static final String UID = "root";
    //密碼
    public static final String PWD = "123";

    //獲取Connection實例
    public static Connection getCon() {
        Connection con = null;
        try {
            Class.forName(DRIVER);//ClassNotFoundException
            con = DriverManager.getConnection(URL, UID, PWD);//SQLException
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return con;
    }

    //關閉Connection對象
    public static void closeCon(Connection con, PreparedStatement ps, ResultSet rs) {
        try {
            if (rs != null) {
                rs.close();
            }
            if (ps != null) {
                ps.close();
            }
            if (con != null) {
                con.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3.數據訪問層 dao

ShopDao

package org.hc.homework.dao;

import org.hc.homework.entity.Page;
import org.hc.homework.entity.Shop;

public interface ShopDao {
    //查詢——添加分頁功能 增加新參數Page page
    Page<Shop> getShopsInPage(Page<Shop> page);
    //查詢 BY no
    Shop getShopByNo(String no);
    //查詢條件查詢總條數
    int getCount(Shop shop);
    //刪除
    boolean deleteShop(String no);
    //修改
    boolean updateShop(Shop shop, String updateNo);
    //新增
    boolean addShop(Shop shop);

}

ShopDaoImpl

package org.hc.homework.dao.daoImpl;

import org.hc.homework.dao.ShopDao;
import org.hc.homework.entity.Page;
import org.hc.homework.entity.Shop;
import org.hc.homework.utils.JdbcUtil;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class ShopDaoImpl implements ShopDao {
    //jdbc API
    Connection con = null;
    PreparedStatement ps = null;
    ResultSet rs = null;

    //查詢 -全查 -模糊查詢 -分頁
    @Override
    public Page<Shop> getShopsInPage(Page<Shop> page) {
        try {
            List<Shop> shops = new ArrayList<>();//符合查詢條件的數據會放在這個集合中，最後放入page.setList()裏
            List<String> wenhao = new ArrayList<>();//問號替換的集合
            Shop newshop = new Shop();//每一行數據
            StringBuffer sql = new StringBuffer("select * from shop where 1=1");
            //從page中拿出查詢條件
            if (page.getLists().size() != 0) {
                newshop = page.getLists().get(0);
            }
            //條件查詢添加的sql
            if (newshop.getType() != null) {
                //type精確查詢
                if (newshop.getType() != null && !newshop.getType().trim().isEmpty()) {
                    sql.append(" and type like ? ");
                    wenhao.add("%" + newshop.getType() + "%");
                }
                //name模糊查詢
                if (newshop.getName() != null && !newshop.getName().trim().isEmpty()) {
                    sql.append(" and name like ? ");
                    wenhao.add("%" + newshop.getName() + "%");
                }
                //address模糊查詢
                if (newshop.getAddress() != null && !newshop.getAddress().trim().isEmpty()) {
                    sql.append(" and address like ? ");
                    wenhao.add("%" + newshop.getAddress() + "%");
                }
                //time模糊查詢
                if (newshop.getTime() != null && !newshop.getTime().trim().isEmpty()) {
                    sql.append(" and time like ? ");
                    wenhao.add("%" + newshop.getTime() + "%");
                }
            }
            //分頁添加的sql 由於limit只能放在where結束後,所以放在這裏
            sql.append(" limit ?,?");
            //預編譯後，將所有問號依次替換
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql.toString());
            //只把除limit的兩個問號都替換掉
            for (int i = 0; i < wenhao.size(); i++) {
                ps.setString(i + 1, wenhao.get(i));
            }
            //替換limit的兩個問號
            ps.setInt(wenhao.size() + 1, page.getStart());
            ps.setInt(wenhao.size() + 2, page.getPageSize());
            rs = ps.executeQuery();
            while (rs.next()) {
                newshop = new Shop(
                        rs.getString(1),
                        rs.getString(2),
                        rs.getString(3),
                        rs.getString(4),
                        rs.getString(5)
                );
                shops.add(newshop);
                page.setLists(shops);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }
        return page;
    }

    //單行查詢 通過no
    @Override
    public Shop getShopByNo(String no) {
        Shop shop = null;
        try {
            String sql = "select * from shop where no=?";
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql);
            ps.setString(1, no);
            rs = ps.executeQuery();
            if (rs.next()) {
                shop = new Shop(
                        rs.getString(1),
                        rs.getString(2),
                        rs.getString(3),
                        rs.getString(4),
                        rs.getString(5)
                );
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }

        return shop;
    }

    //count需要根據條件查詢改變
    @Override
    public int getCount(Shop shop) {
        int count = 0;
        try {
            ArrayList<String> wenhao = new ArrayList<>();//問號替換的集合
            StringBuffer sql = new StringBuffer("select count(*) from shop where 1=1 ");
            if (shop != null) {
                //type精確查詢
                if (shop.getType() != null && !shop.getType().trim().isEmpty()) {
                    sql.append(" and type like ? ");
                    wenhao.add("%" + shop.getType() + "%");
                }
                //name模糊查詢
                if (shop.getName() != null && !shop.getName().trim().isEmpty()) {
                    sql.append(" and name like ? ");
                    wenhao.add("%" + shop.getName() + "%");
                }
                //address模糊查詢
                if (shop.getAddress() != null && !shop.getAddress().trim().isEmpty()) {
                    sql.append(" and address like ? ");
                    wenhao.add("%" + shop.getAddress() + "%");
                }
                //time模糊查詢
                if (shop.getTime() != null && !shop.getTime().trim().isEmpty()) {
                    sql.append(" and time like ? ");
                    wenhao.add("%" + shop.getTime() + "%");
                }
            }
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql.toString());
            //替換問號
            for (int i = 0; i < wenhao.size(); i++) {
                ps.setString(i + 1, wenhao.get(i));
            }
            rs = ps.executeQuery();
            if (rs.next()) {
                count = rs.getInt(1);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }
        return count;
    }

    //刪除 通過no
    @Override
    public boolean deleteShop(String no) {
        try {
            String sql = "delete from shop where no=?";
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql);
            ps.setString(1, no);
            ps.execute();
            return true;
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }
        return false;
    }

    //修改 通過shop對象 where=no
    @Override
    public boolean updateShop(Shop shop, String updateNo) {
        try {
            String sql = "update shop set no=?,name=?,address=?,type=? where no =?";
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql);
            ps.setString(1, shop.getNo());
            ps.setString(2, shop.getName());
            ps.setString(3, shop.getAddress());
            ps.setString(4, shop.getType());
            ps.setString(5, updateNo);
            ps.execute();
            return true;
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }
        return false;
    }

    //新增
    @Override
    public boolean addShop(Shop shop) {
        try {
            String sql = "insert into shop values(?,?,?,?,?)";
            con = JdbcUtil.getCon();
            ps = con.prepareStatement(sql);
            ps.setString(1, shop.getNo());
            ps.setString(2, shop.getName());
            ps.setString(3, shop.getTime());
            ps.setString(4, shop.getAddress());
            ps.setString(5, shop.getType());
            ps.execute();
            return true;
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtil.closeCon(con, ps, rs);
        }
        return false;
    }
}

4.業務邏輯層 service

ShopService

package org.hc.homework.service;

import org.hc.homework.entity.Page;
import org.hc.homework.entity.Shop;

public interface ShopService {
    //查詢-分頁
    Page<Shop> getShopsInPage(Page<Shop> page);
    //查詢 BY no
    Shop getShopByNo(String no);
    //刪除
    boolean deleteShop(String no);
    //修改
    boolean updateShop(Shop shop, String updateNo);
    //新增
    boolean addShop(Shop shop);
}

ShopServiceImpl

package org.hc.homework.service.serviceImpl;

import org.hc.homework.dao.ShopDao;
import org.hc.homework.dao.daoImpl.ShopDaoImpl;
import org.hc.homework.entity.Page;
import org.hc.homework.entity.Shop;
import org.hc.homework.service.ShopService;


public class ShopServiceImpl implements ShopService {
    ShopDao shopDao=new ShopDaoImpl();

    @Override
    public Page<Shop> getShopsInPage(Page<Shop> page) {
        if (page.getLists().size()==0){
            page.setTotalCount(shopDao.getCount(new Shop()));//總條數賦值進去
        }else{
            page.setTotalCount(shopDao.getCount(page.getLists().get(0)));//總條數賦值進去
        }
        return shopDao.getShopsInPage(page);
    }

    @Override
    public Shop getShopByNo(String no) {
        return shopDao.getShopByNo(no);
    }

    @Override
    public boolean deleteShop(String no) {
        return shopDao.deleteShop(no);
    }

    @Override
    public boolean updateShop(Shop shop, String updateNo) {
        return shopDao.updateShop(shop,updateNo);
    }

    @Override
    public boolean addShop(Shop shop) {
        return shopDao.addShop(shop);
    }
}

5.控制層 Servlet

通過每次跳到控制器的opereation的值決定是哪個操作

package org.hc.homework.servlet;

import org.hc.homework.entity.Page;
import org.hc.homework.entity.Shop;
import org.hc.homework.service.ShopService;
import org.hc.homework.service.serviceImpl.ShopServiceImpl;

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 java.io.IOException;
import java.util.ArrayList;

@WebServlet(name = "ShopServlet")
public class ShopServlet extends HttpServlet {
    private static final long serialVersionUID = -6283161696285843678L;
    ShopService shopService = new ShopServiceImpl();

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        ArrayList<Shop> shops = null;
        String operation = request.getParameter("operation");//操作字符
        Page<Shop> page = new Page();
        if (request.getParameter("currentPage") != null) {
            page.setCurrentPage(Integer.parseInt(request.getParameter("currentPage")));//當前頁
        } else {
            page.setCurrentPage(1);
        }
        if (request.getParameter("pageSize") != null) {
            page.setPageSize(Integer.parseInt(request.getParameter("pageSize")));//每頁的條數
        } else {
            page.setPageSize(4);
        }

        //判斷業務
        if (operation.equals("queryAll")) {
            //全查
            page = shopService.getShopsInPage(page);
        } else if (operation.equals("query")) {
            //條件查詢
            Shop shop = new Shop(
                    null,
                    request.getParameter("name"),
                    request.getParameter("time"),
                    request.getParameter("address"),
                    request.getParameter("type")
            );
            request.setAttribute("queryShop", shop);
            page.getLists().add(shop);
            page = shopService.getShopsInPage(page);
            //測試
            log("條件查詢page的各個屬性：" +
                    "\npage.getTotalCount=" + page.getTotalCount() +
                    "\npage.getPageSize=" + page.getPageSize() +
                    "\npage.getStart=" + page.getStart() +
                    "\npage.getCurrentPage=" + page.getCurrentPage() +
                    "\npage.getName=" + shop.getName() +
                    "\npage.getType=" + shop.getType() +
                    "\npage.getTime=" + shop.getTime() +
                    "\npage.getAddress=" + shop.getAddress()
            );
        } else if (operation.split("&")[0].equals("delete")) {
            //刪除,由&拆分字符串，拿下標爲0的數組內容
            String no = operation.split("&")[1];
            boolean flag = shopService.deleteShop(no);
            if (flag) {
                request.setAttribute("Success", "<script>alert('刪除成功')</script>");
            } else {
                request.setAttribute("Success", "<script>alert('ERROR！服務器錯誤')</script>");
            }
            page = shopService.getShopsInPage(page);//全查
        } else if (operation.split("&")[0].equals("toUpdate")) {
            //to修改,由&拆分字符串，拿下標爲0的數組內容
            String no = operation.split("&")[1];
            Shop shop = shopService.getShopByNo(no);
            request.setAttribute("shop", shop);//返回原數據
            request.getRequestDispatcher("updateList.jsp").forward(request, response);
            return;
        } else if (operation.equals("update")) {
            //修改
            String updateNo = request.getParameter("updateNo");
            Shop shop = new Shop(
                    request.getParameter("no"),
                    request.getParameter("name"),
                    request.getParameter("time"),
                    request.getParameter("address"),
                    request.getParameter("type")
            );
            boolean flag = shopService.updateShop(shop, updateNo);
            if (flag) {
                request.setAttribute("Success", "<script>alert('修改成功')</script>");
            } else {
                request.setAttribute("Success", "<script>alert('ERROR！服務器錯誤')</script>");
            }
            page = shopService.getShopsInPage(page);//全查
        } else if (operation.equals("add")) {
            //新增
            Shop shop = new Shop(
                    request.getParameter("no"),
                    request.getParameter("name"),
                    request.getParameter("time"),
                    request.getParameter("address"),
                    request.getParameter("type")
            );
            boolean flag = shopService.addShop(shop);
            if (flag) {
                request.setAttribute("Success", "<script>alert('新增成功')</script>");
            } else {
                request.setAttribute("Success", "<script>alert('ERROR！服務器錯誤')</script>");
            }
            page = shopService.getShopsInPage(page);//全查
        } else if (operation.equals("toAdd")) {
            //to新增
            request.getRequestDispatcher("addList.jsp").forward(request, response);
            return;
        }
        request.setAttribute("page", page);
        request.getRequestDispatcher("list.jsp").forward(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

java類就在此結束了，下面是JSP和CSS

6.JSP和CSS

center.css

body,div,table,form{
    margin: 0 auto;
    text-align: center;
}
#div1{
    margin-top: 30px;
}
#div2{
    margin-top: 50px;
}
#list{
    margin-top: 20px;
}

index.jsp（初始界面）

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>welcome</title>
  </head>
  <body>
  <form action="ShopServlet" method="post">
      <button type="submit" value="列表">列表</button>
      <input type="hidden" value="queryAll" name="operation">
  </form>
  </body>
</html>

list.jsp（全查列表）使用了EL表達式和JSTL，需要導入JSTL的包

<%@ page contentType="text/html;charset=UTF-8" %>
<%-- 引入JSTL --%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
    <meta charset="UTF-8">
    <title>列表</title>
    <link type="text/css" rel="stylesheet" href="css/center.css">
</head>

<%--是否刪除、修改、新增成功--%>
<c:if test="${Success != null}">
    ${Success}
</c:if>

<body>
<%-- 搜索,條件查詢 operation=qeury --%>
<div id="div1">
    <form action="ShopServlet" method="post">
        商品名：<input type="text" name="name" id="name" value="${queryShop.name}">
        商品種類：<input type="text" name="type" id="type" value="${queryShop.type}">
        產地：<input type="text" name="address" id="address" value="${queryShop.address}">
        生產日期：<input type="text" name="time" id="time" value="${queryShop.time}">
        <input type="hidden" name="operation" value="query">
        <button type="submit">搜索</button>
    </form>
</div>
<%-- 新增 --%>
<div id="div2">
    <form action="ShopServlet" method="post">
        <input type="hidden" name="operation" value="toAdd">
        <button type="submit" style="width: 100px">新增商品信息</button>
    </form>
</div>
<%--列表--%>
<div id="list">
    <form action="ShopServlet" method="post">
        <table border="1" cellspacing="0" cellpadding="5" style="text-align: center;margin: 0 auto">
            <tr>
                <td>商品編號</td>
                <td>商品名</td>
                <td>生產日期</td>
                <td>產地</td>
                <td>商品類型</td>
                <td>刪除</td>
                <td>修改</td>
            </tr>
            <c:forEach items="${myPage.lists}" var="shop">
                <tr>
                    <td>${shop.no}</td>
                    <td>${shop.name}</td>
                    <td>${shop.time}</td>
                    <td>${shop.address}</td>
                    <td>${shop.type}</td>
                    <td>
                        <button type="submit" name="operation" value="delete&${shop.no}">刪除</button>
                    </td>
                    <td>
                        <button type="submit" name="operation" value="toUpdate&${shop.no}">修改</button>
                    </td>
                </tr>
            </c:forEach>
        </table>
    </form>
</div>
<div>
    <%-- 不是首頁和尾頁，即中間頁，即 首頁 上一頁 下一頁 尾頁 --%>
    <c:if test="${myPage.currentPage>1 && myPage.currentPage<myPage.totalPage}">
        <a href="ShopServlet?operation=query&currentPage=1" onclick="getKey(this)">首頁</a>
        <a href="ShopServlet?operation=query&currentPage=${myPage.currentPage-1}" onclick="getKey(this)">上一頁</a>
        <a href="ShopServlet?operation=query&currentPage=${myPage.currentPage+1}" onclick="getKey(this)">下一頁</a>
        <a href="ShopServlet?operation=query&currentPage=${myPage.totalPage}" onclick="getKey(this)">尾頁</a>
    </c:if>

    <%-- 尾頁，只有 首頁 上一頁 --%>
    <c:if test="${myPage.currentPage == myPage.totalPage && myPage.totalPage !=1}">
        <a href="ShopServlet?operation=query&currentPage=1" onclick="getKey(this)">首頁</a>
        <a href="ShopServlet?operation=query&currentPage=${myPage.currentPage-1}" onclick="getKey(this)">上一頁</a>
    </c:if>

    <%-- 首頁，只有 下一頁 尾頁 --%>
    <c:if test="${myPage.currentPage == 1 && myPage.totalPage !=1}">
        <a href="ShopServlet?operation=query&currentPage=${myPage.currentPage+1}" onclick="getKey(this)">下一頁</a>
        <a href="ShopServlet?operation=query&currentPage=${myPage.totalPage}" onclick="getKey(this)">尾頁</a>
    </c:if>

</div>
<script>

    function getKey(a) {
        var name = document.getElementById("name").value;
        var type = document.getElementById("type").value;
        var address = document.getElementById("address").value;
        var time = document.getElementById("time").value;
        a.href += "&name=" + name + "&type=" + type + "&address=" + address + "&time=" + time;
    }
</script>
</body>
</html>

addList.jsp（新增頁面）

<%@ page contentType="text/html;charset=UTF-8"
         language="java"
         import="org.hc.homework.entity.Shop"
%>
<html>
<head>
    <title>新增</title>
    <link type="text/css" rel="stylesheet" href="css/center.css">
</head>
<body>
<div>
    <form action="ShopServlet" method="post">
        <input type="hidden" value="add" name="operation">
        <table>
            <tr>
                <td colspan="2">新增商品信息</td>
                <td colspan="2">
                    <button type="submit">確定</button>
                </td>
            </tr>
            <tr>
                <td>商品編號</td>
                <td><input type="text" value="" name="no"></td>
                <td>商品名稱</td>
                <td><input type="text" value="" name="name"></td>
            </tr>
            <tr>
                <td>商品產地</td>
                <td><input type="text" value="" name="address"></td>
                <td>商品類型</td>
                <td><input type="text" value="" name="type"></td>
            </tr>
            <tr>
                <td>生產日期</td>
                <td><input type="text" value="" name="time"></td>
            </tr>
        </table>
    </form>
</div>
</body>
</html>

updateList.jsp（修改頁面）

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%-- 引入JSTL --%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
    <title>修改</title>
    <link type="text/css" rel="stylesheet" href="css/center.css">
</head>
<body>
<div>
    <form action="ShopServlet" method="post">
        <input type="hidden" value="${shop.no}" name="updateNo">
        <input type="hidden" value="update" name="operation">
        <table>
            <tr>
                <td colspan="2">修改商品信息</td>
                <td colspan="2">
                    <button type="submit">確定</button>
                </td>
            </tr>
            <tr>
                <td>商品編號</td>
                <td><input type="text" value="${shop.no}" name="no"></td>
                <td>商品名稱</td>
                <td><input type="text" value="${shop.name}" name="name"></td>
            </tr>
            <tr>
                <td>商品產地</td>
                <td><input type="text" value="${shop.address}" name="address"></td>
                <td>商品類型</td>
                <td><input type="text" value="${shop.type}" name="type"></td>
            </tr>
        </table>
    </form>
</div>
</body>
</html>

7.在tomcat環境下跑起來

主要是分頁功能的展示，其他就不展示啦

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