综合练习27

一、页面调整

　

　list.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2">
            </div>
            <div class="form-group">
                <label for="exampleInputAddress2">籍贯</label>
                <input type="text" class="form-control" id="exampleInputAddress2">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail2">
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>


    <div style="float: right;margin: 5px">
        <a class="btn btn-primary" href="add.html">添加联系人</a>
        <a class="btn btn-primary" href="add.html">删除选中</a>
    </div>
    <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th><input type="checkbox"></th>
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>
        <c:forEach items="${users}" var="user" varStatus="s">
            <tr>
                <td><input type="checkbox"></td>
                <td>${user.id}</td>
                <td>${user.name}</td>
                <td>${user.gendar}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${use.qq}</td>
                <td>${user.email}</td>
                <td><a class="btn btn-default btn-sm" href="update.html">修改</a>&nbsp;<a class="btn btn-default btn-sm" href="">删除</a></td>
            </tr>
        </c:forEach>

    </table>
    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <li>
                    <a href="#" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
                <li><a href="#">1</a></li>
                <li><a href="#">2</a></li>
                <li><a href="#">3</a></li>
                <li><a href="#">4</a></li>
                <li><a href="#">5</a></li>
                <li>
                    <a href="#" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共16条记录，共4页
                </span>
            </ul>
        </nav>
    </div>
</div>
</body>
</html>

二、简单功能

　1. 列表查询
　2. 登录
　3. 添加
　4. 删除
　5. 修改

　1、登录

　　

　　login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-CN">
<head>
    <meta charset="utf-8"/>
    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
    <meta name="viewport" content="width=device-width, initial-scale=1"/>
    <title>管理员登录</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <script type="text/javascript">
        //切换验证码
        function refreshCode() {
            //1.获取验证码图片对象
            var vcode = document.getElementById("vcode");
            //2.设置其src属性，加时间戳
            vcode.src = "${pageContext.request.contextPath}/checkCodeServlet?time="+new Date().getTime();
        }
    </script>
</head>
<body>
<div class="container" style="width: 400px;">
    <h3 style="text-align: center;">管理员登录</h3>
    <form action="${pageContext.request.contextPath}/loginServlet" method="post">
        <div class="form-group">
            <label for="user">用户名：</label>
            <input type="text" name="username" class="form-control" id="user" placeholder="请输入用户名"/>
        </div>

        <div class="form-group">
            <label for="password">密码：</label>
            <input type="password" name="password" class="form-control" id="password" placeholder="请输入密码"/>
        </div>

        <div class="form-inline">
            <label for="vcode">验证码：</label>
            <input type="text" name="verifycode" class="form-control" id="verifycode" placeholder="请输入验证码" style="width: 120px;"/>
            <a href="javascript:refreshCode()">
                <img src="${pageContext.request.contextPath}/checkCodeServlet" title="看不清点击刷新" id="vcode"/>
            </a>
        </div>
        <hr/>
        <div class="form-group" style="text-align: center;">
            <input class="btn btn btn-primary" type="submit" value="登录">
        </div>
    </form>

    <!-- 出错显示的信息框 -->
    <div class="alert alert-warning alert-dismissible" role="alert">
        <button type="button" class="close" data-dismiss="alert" >
            <span>&times;</span></button>
        <strong>${login_msg}</strong>
    </div>
</div>
</body>
</html>

　　src/cn/itcast/web/servlet/CheckCodeServlet：

package cn.itcast.web.servlet;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 验证码
 */
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
        
        //服务器通知浏览器不要缓存
        response.setHeader("pragma","no-cache");
        response.setHeader("cache-control","no-cache");
        response.setHeader("expires","0");
        
        //在内存中创建一个长80，宽30的图片，默认黑色背景
        //参数一：长
        //参数二：宽
        //参数三：颜色
        int width = 80;
        int height = 30;
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        
        //获取画笔
        Graphics g = image.getGraphics();
        //设置画笔颜色为灰色
        g.setColor(Color.GRAY);
        //填充图片
        g.fillRect(0,0, width,height);
        
        //产生4个随机验证码，12Ey
        String checkCode = getCheckCode();
        //将验证码放入HttpSession中
        request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);
        
        //设置画笔颜色为黄色
        g.setColor(Color.YELLOW);
        //设置字体的小大
        g.setFont(new Font("黑体",Font.BOLD,24));
        //向图片上写入验证码
        g.drawString(checkCode,15,25);
        
        //将内存中的图片输出到浏览器
        //参数一：图片对象
        //参数二：图片的格式，如PNG,JPG,GIF
        //参数三：图片输出到哪里去
        ImageIO.write(image,"PNG",response.getOutputStream());
    }
    /**
     * 产生4位随机字符串 
     */
    private String getCheckCode() {
        String base = "0123456789ABCDEFGabcdefg";
        int size = base.length();
        Random r = new Random();
        StringBuffer sb = new StringBuffer();
        for(int i=1;i<=4;i++){
            //产生0到size-1的随机值
            int index = r.nextInt(size);
            //在base字符串中获取下标为index的字符
            char c = base.charAt(index);
            //将c放入到StringBuffer中去
            sb.append(c);
        }
        return sb.toString();
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}

　　数据库

create database day18; -- 创建数据库
use day18;                -- 使用数据库
create table user(   -- 创建表
    id int primary key auto_increment,
    name varchar(20) not null,
    gendar varchar(5),
    age int,
    address varchar(32),
    qq    varchar(20),
    email varchar(50),
    username varchar(32),
    password varchar(32)
);

　　

User.java：
package cn.itcast.domain;

public class User {

    private int id;
    private String name;
    private String gendar;
    private int age;
    private String address;
    private String qq;
    private String email;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public String getGendar() {
        return gendar;
    }

    public void setGendar(String gendar) {
        this.gendar = gendar;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

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

    public String getQq() {
        return qq;
    }

    public void setQq(String qq) {
        this.qq = qq;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", gendar='" + gendar + '\'' +
                ", age=" + age +
                ", address='" + address + '\'' +
                ", qq='" + qq + '\'' +
                ", email='" + email + '\'' +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

　src/cn/itcast/web/servlet/LoginServlet：

package cn.itcast.web.servlet;

import cn.itcast.domain.User;
import cn.itcast.service.UserService;
import cn.itcast.service.impl.UserServiceImpl;
import org.apache.commons.beanutils.BeanUtils;

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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取数据
        String verifycode = request.getParameter("verifycode");

        //3.验证码校验
        HttpSession session = request.getSession();
        String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
        session.removeAttribute(checkcode_server);//确保验证码一次性
        if(!checkcode_server.equalsIgnoreCase(verifycode)){
            //验证码不正确
            //提示信息
            request.setAttribute("login_msg","验证码错误！");
            //跳转登录页面
            request.getRequestDispatcher("/login.jsp").forward(request,response);
            return;
        }

        Map<String, String[]> map = request.getParameterMap();
        //4.封装User对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }

        //5.调用service查询
        UserService userService = new UserServiceImpl();
        User loginUser = userService.login(user);

        //6.判断是否登录成功
        if(loginUser != null){
            //登录成功
            //将用户存入session
            session.setAttribute("user",loginUser);
            //跳转页面
            response.sendRedirect(request.getContextPath()+"/index.jsp");
        }else{
            //登录失败
            //提示信息
            request.setAttribute("login_msg","用户名或密码错误！");
            //跳转登录页面
            request.getRequestDispatcher("/login.jsp").forward(request,response);
        }
    }

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

　UserDao.java：

package cn.itcast.dao;

import cn.itcast.domain.User;
import java.util.List;

/**
 * 用户操作的DAO
 */
public interface UserDao {

    public List<User> findAll();

    public User findUserByUsernameAndPassword(String username,String password);
}
　UserDaoImpl：
package cn.itcast.dao.impl;

import cn.itcast.dao.UserDao;
import cn.itcast.domain.User;
import cn.itcast.util.JDBCUtils;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;

public class UserDaoImpl implements UserDao {

    private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource());

    @Override
    public List<User> findAll() {
        //使用jdbc操作数据库
        //1.定义sql
        String sql = "select * from user";
        List<User> users = template.query(sql, new BeanPropertyRowMapper<User>(User.class));
        return users;
    }

    @Override
    public User findUserByUsernameAndPassword(String username,String password) {
        try {
            String sql = "select * from user where username = ? and password = ?";
            User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), username, password);
            return user;
        }catch (Exception e){
            e.printStackTrace();
            return  null;
        }
    }
}
　UserService.java：
package cn.itcast.service;

import cn.itcast.domain.User;

import java.util.List;

/**
 * 用户管理的业务接口
 */
public interface UserService {

    /**
     * 查询所有用户信息
     * @return
     */
    public List<User> findAll();

    public User login(User user);
}
　UserServiceImpl.java
package cn.itcast.service.impl;

import cn.itcast.dao.UserDao;
import cn.itcast.dao.impl.UserDaoImpl;
import cn.itcast.domain.User;
import cn.itcast.service.UserService;
import java.util.List;

public class UserServiceImpl implements UserService {

    private UserDao dao = new UserDaoImpl();

    @Override
    public List<User> findAll() {
        //调用dao完成查询
        return dao.findAll();
    }

    @Override
    public User login(User user) {
        return dao.findUserByUsernameAndPassword(user.getUsername(),user.getPassword());
    }
}

　　index.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-CN">
<head>
  <meta charset="utf-8"/>
  <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
  <meta name="viewport" content="width=device-width, initial-scale=1"/>
  <title>首页</title>

  <!-- 1. 导入CSS的全局样式 -->
  <link href="css/bootstrap.min.css" rel="stylesheet">
  <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
  <script src="js/jquery-2.1.0.min.js"></script>
  <!-- 3. 导入bootstrap的js文件 -->
  <script src="js/bootstrap.min.js"></script>
  <script type="text/javascript">
  </script>
</head>
<body>
<div>${user.name},欢迎您！</div>
<div align="center">
  <a
          href="${pageContext.request.contextPath}/userListServlet" style="text-decoration:none;font-size:33px">查询所有用户信息
  </a>
</div>
</body>
</html>

　　浏览器访问http://localhost/day18/login.jsp

　　输入错误的验证码

　　　

　　输入错误的用户名或密码及正确的验证码

　　　

　　输入正确的用户名、密码及验证码：

　　　

　2、添加

　　

 　　add.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>添加用户</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <center><h3>添加联系人页面</h3></center>
    <form action="${pageContext.request.contextPath}/addUserServlet" method="post">
        <div class="form-group">
            <label for="name">姓名：</label>
            <input type="text" class="form-control" id="name" name="name" placeholder="请输入姓名">
        </div>

        <div class="form-group">
            <label>性别：</label>
            <input type="radio" name="gendar" value="男" checked="checked"/>男
            <input type="radio" name="gendar" value="女"/>女
        </div>

        <div class="form-group">
            <label for="age">年龄：</label>
            <input type="text" class="form-control" id="age" name="age" placeholder="请输入年龄">
        </div>

        <div class="form-group">
            <label for="address">籍贯：</label>
            <select id="address" name="address"  class="form-control" id="jiguan">
                <option value="广东">广东</option>
                <option value="广西">广西</option>
                <option value="湖南">湖南</option>
            </select>
        </div>

        <div class="form-group">
            <label for="qq">QQ：</label>
            <input type="text" id="qq" class="form-control" name="qq" placeholder="请输入QQ号码"/>
        </div>

        <div class="form-group">
            <label for="email">Email：</label>
            <input type="text" id="email" class="form-control" name="email" placeholder="请输入邮箱地址"/>
        </div>

        <div class="form-group" style="text-align: center">
            <input class="btn btn-primary" type="submit" value="提交" />
            <input class="btn btn-default" type="reset" value="重置" />
            <input class="btn btn-default" type="button" value="返回" />
        </div>
    </form>
</div>
</body>
</html>

　　AddUserServlet

package cn.itcast.web.servlet;

import cn.itcast.domain.User;
import cn.itcast.service.UserService;
import cn.itcast.service.impl.UserServiceImpl;
import org.apache.commons.beanutils.BeanUtils;
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.lang.reflect.InvocationTargetException;
import java.util.Map;

@WebServlet("/addUserServlet")
public class AddUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取参数
        Map<String, String[]> map = request.getParameterMap();
        //3.封装对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //4.调用service保存
        UserService service = new UserServiceImpl();
        service.addUser(user);

        //5.跳转到userListServlet
        response.sendRedirect(request.getContextPath()+"/userListServlet");
    }

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

　　UserService

    /**
     * 保存User
     * @param user
     */
    void addUser(User user);

　　UserServiceImpl

    @Override
    public void addUser(User user) {
        dao.add(user);
    }

　　UserDao

    void add(User user);

　　UserDaoImpl

    @Override
    public void add(User user) {
        String sql = "insert into user values (null,?,?,?,?,?,?,null,null)";
        template.update(sql,user.getName(),user.getGendar(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail());
    }

　　重启tomcat服务器，浏览器访问http://localhost/day18/add.jsp

　　输入用户信息，提交

　　

　3、删除

　　点击右侧的删除按钮，记录删除

　　

 　　list.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
    <script>
        function deleteUser(id){
            //用户安全提示
            if(confirm("您确定要删除吗？")){
                //访问路径
                location.href = "${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }
    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2">
            </div>
            <div class="form-group">
                <label for="exampleInputAddress2">籍贯</label>
                <input type="text" class="form-control" id="exampleInputAddress2">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail2">
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>


    <div style="float: right;margin: 5px">
        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="add.html">删除选中</a>
    </div>
    <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th><input type="checkbox"></th>
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>
        <c:forEach items="${users}" var="user" varStatus="s">
            <tr>
                <td><input type="checkbox"></td>
                <td>${user.id}</td>
                <td>${user.name}</td>
                <td>${user.gendar}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${use.qq}</td>
                <td>${user.email}</td>
                <td>
                    <a class="btn btn-default btn-sm" href="update.html">修改</a>&nbsp;
                    <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>
                </td>
            </tr>
        </c:forEach>

    </table>
    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <li>
                    <a href="#" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
                <li><a href="#">1</a></li>
                <li><a href="#">2</a></li>
                <li><a href="#">3</a></li>
                <li><a href="#">4</a></li>
                <li><a href="#">5</a></li>
                <li>
                    <a href="#" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共16条记录，共4页
                </span>
            </ul>
        </nav>
    </div>
</div>
</body>
</html>

　　DelUserServlet

@WebServlet("/delUserServlet")
public class DelUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.获取id
        String id = request.getParameter("id");
        //2.调用service删除
        UserService service = new UserServiceImpl();
        service.deleteUser(id);

        //3.跳转到查询所有Servlet
        response.sendRedirect(request.getContextPath()+"/userListServlet");
    }

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

　　UserService

    /**
     * 根据id删除User
     * @param id
     */
    void deleteUser(String id);

　　UserServiceImpl

    @Override
    public void deleteUser(String id) {
        dao.delete(Integer.parseInt(id));
    }

　　UserDao

    void delete(int id);

　　UserDaoImpl

    @Override
    public void delete(int id) {
        String sql = "delete from user where id = ?";
        template.update(sql,id);
    }

　　浏览器访问http://localhost/day18，然后进入列表页，点击“删除”按钮

　　　

　4、修改

　　点击“修改”按钮

　　

　　list.jsp

                <td>
                    <a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>&nbsp;
                    <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>
                </td>

　　FindUserServlet

@WebServlet("/findUserServlet")
public class FindUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //获取id
        String id = request.getParameter("id");
        //2.调用Service查询
        UserService service = new UserServiceImpl();
        User user = service.findUserById(id);

        //3.将user存入request域
        request.setAttribute("user",user);
        //4.转发到update.jsp
        request.getRequestDispatcher("/update.jsp").forward(request,response);
    }

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

　　UserService

    User findUserById(String id);

　　UserServiceImpl

    @Override
    public User findUserById(String id) {
        return dao.findById(Integer.parseInt(id));
    }

　　UserDao

    User findById(int id);

　　UserDaoImpl 

    @Override
    public User findById(int id) {
        String sql = "select * from user where id = ?";
        return template.queryForObject(sql,new BeanPropertyRowMapper<User>(User.class),id);
    }

　　update.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>修改用户</title>

    <link href="css/bootstrap.min.css" rel="stylesheet">
    <script src="js/jquery-2.1.0.min.js"></script>
    <script src="js/bootstrap.min.js"></script>

</head>
<body>
<div class="container" style="width: 400px;">
    <h3 style="text-align: center;">修改联系人</h3>
    <form action="${pageContext.request.contextPath}/updateUserServlet" method="post">
        <%--隐藏域 提交id--%>
        <input type="hidden" name="id" value="${user.id}">
        <div class="form-group">
            <label for="name">姓名：</label>
            <input type="text" class="form-control" id="name" name="name" value="${user.name}" readonly="readonly" placeholder="请输入姓名" />
        </div>

        <div class="form-group">
            <label>性别：</label>
            <c:if test="${user.gendar == '男'}">
                <input type="radio" name="gendar" value="男" checked />男
                <input type="radio" name="gendar" value="女" />女
            </c:if>
            <c:if test="${user.gendar == '女'}">
                <input type="radio" name="gendar" value="男" />男
                <input type="radio" name="gendar" value="女" checked />女
            </c:if>
        </div>

        <div class="form-group">
            <label for="age">年龄：</label>
            <input type="text" class="form-control" id="age" value="${user.age}" name="age" placeholder="请输入年龄" />
        </div>

        <div class="form-group">
            <label for="address">籍贯：</label>
            <select name="address" id="address" class="form-control" >
                <c:if test="${user.address == '北京'}">
                    <option value="北京" selected>北京</option>
                    <option value="上海" >上海</option>
                    <option value="广州" >广州</option>
                </c:if>
                <c:if test="${user.address == '上海'}">
                    <option value="北京" >北京</option>
                    <option value="上海" selected>上海</option>
                    <option value="广州" >广州</option>
                </c:if>
                <c:if test="${user.address == '广州'}">
                    <option value="北京" >北京</option>
                    <option value="上海" >上海</option>
                    <option value="广州" selected>广州</option>

                </c:if>
            </select>
        </div>

        <div class="form-group">
            <label for="qq">QQ：</label>
            <input type="text" id="qq" class="form-control" value="${user.qq}" name="qq" placeholder="请输入QQ号码"/>
        </div>

        <div class="form-group">
            <label for="email">Email：</label>
            <input type="text" id="email" class="form-control" value="${user.email}" name="email" placeholder="请输入邮箱地址"/>
        </div>

        <div class="form-group" style="text-align: center">
            <input class="btn btn-primary" type="submit" value="提交" />
            <input class="btn btn-default" type="reset" value="重置" />
            <input class="btn btn-default" type="button" value="返回"/>
        </div>
    </form>
</div>
</body>
</html>

　　UpdateUserServlet

@WebServlet("/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取map
        Map<String, String[]> map = request.getParameterMap();
        //3.封装对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }

        //4.调用Service修改
        UserService service = new UserServiceImpl();
        service.updateUser(user);

        //跳转到查询所有
        response.sendRedirect(request.getContextPath()+"/userListServlet");
    }

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

　　UserService

    /**
     * 修改用户信息
     * @param user
     */
    void updateUser(User user);

　　UserServiceImpl

    @Override
    public void updateUser(User user) {
        dao.update(user);
    }

　　UserDao

    void update(User user);

　　UserDaoImpl 

    @Override
    public void update(User user) {
        String sql = "update user set name = ?, gendar = ?,age = ?,address = ?,qq = ?,email = ? where id = ? ";
        template.update(sql,user.getName(),user.getGendar(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail(),user.getId());
    }

　　浏览器访问http://localhost/day18，然后进入列表页，点击“修改”按钮

　　　

三、复杂功能
　1. 删除选中
　2. 分页查询
　　好处：
　　　　1. 减轻服务器内存的开销
　　　　2. 提升用户体验
　3. 复杂条件查询

　1、删除选中

　　

　　list.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
    <script>
        function deleteUser(id){
            //用户安全提示
            if(confirm("您确定要删除吗？")){
                //访问路径
                location.href = "${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }
        window.onload = function() {
            //给删除选中按钮添加单击事件
            document.getElementById("delSelected").onclick = function () {

                if(confirm("您确定要删除选中条目吗？")){
                    var flag = false;
                    //判断是否有选中条目
                    var cbs = document.getElementsByName("uid");
                    for (var i = 0; i < cbs.length; i++) {
                        if(cbs[i].checked){
                            flag = true;
                            break;
                        }
                    }
                    //有条目选中，表单提交
                    if(flag){
                        document.getElementById("form").submit();
                    }
                }
            }

            //全选全不选复选框功能
            //1.获取第一个cb
            document.getElementById("firstCb").onclick = function () {
                //2.获取下边列表中所有的cb
                var cbs = document.getElementsByName("uid");
                //3.遍历
                for (var i = 0; i < cbs.length; i++) {
                    //4.设置这些cbs[i]的checked状态=firstCb.checked
                    cbs[i].checked = this.checked;
                }
            }
        }
    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2">
            </div>
            <div class="form-group">
                <label for="exampleInputAddress2">籍贯</label>
                <input type="text" class="form-control" id="exampleInputAddress2">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail2">
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>

    <div style="float: right;margin: 5px">
        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="javascript:void(0);" id="delSelected">删除选中</a>
    </div>
    <form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
        <table border="1" class="table table-bordered table-hover">
            <tr class="success">
                <th><input type="checkbox" id="firstCb"></th>
                <th>编号</th>
                <th>姓名</th>
                <th>性别</th>
                <th>年龄</th>
                <th>籍贯</th>
                <th>QQ</th>
                <th>邮箱</th>
                <th>操作</th>
            </tr>
            <c:forEach items="${users}" var="user" varStatus="s">
                <tr>
                    <td><input type="checkbox" name="uid" value="${user.id}"></td>
                    <td>${s.count}</td>
                    <td>${user.name}</td>
                    <td>${user.gendar}</td>
                    <td>${user.age}</td>
                    <td>${user.address}</td>
                    <td>${use.qq}</td>
                    <td>${user.email}</td>
                    <td>
                        <a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>&nbsp;
                        <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>
                    </td>
                </tr>
            </c:forEach>

        </table>
    </form>

    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <li>
                    <a href="#" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
                <li><a href="#">1</a></li>
                <li><a href="#">2</a></li>
                <li><a href="#">3</a></li>
                <li><a href="#">4</a></li>
                <li><a href="#">5</a></li>
                <li>
                    <a href="#" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共16条记录，共4页
                </span>
            </ul>
        </nav>
    </div>
</div>
</body>
</html>

　　DelSelectedServlet

@WebServlet("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.获取选中id
        String[] uids = request.getParameterValues("uid");
        //2.调用service删除
        UserService service = new UserServiceImpl();
        service.delSelectedUser(uids);

        response.sendRedirect(request.getContextPath()+"/userListServlet");
    }

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

　　UserService

    /**
     * 批量删除用户
     * @param ids
     */
    void delSelectedUser(String[] ids);

　　UserServiceImpl

    @Override
    public void delSelectedUser(String[] ids) {
        if(ids != null  && ids.length > 0){
            //1.遍历数组
            for (String id : ids) {
                //2.调用dao删除
                dao.delete(Integer.parseInt(id));
            }
        }
    }

　　浏览器访问http://localhost/day18，然后进入列表页，选中第一个复选框，点击“删除选中”按钮

　　　

　2、分页查询

　　

　　

　　PageBean.java

package cn.itcast.domain;

import java.util.List;

/**
 * 分页对象
 */
public class PageBean<T> {

    private int totalCount; //总记录数
    private int totalPage;  //总页码
    private List<T> list;   //每页的数据
    private int currentPage;    //当前页码
    private int rows;       //每页显示的记录数

    public int getTotalCount() {
        return totalCount;
    }

    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }

    public int getTotalPage() {
        return totalPage;
    }

    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }

    public int getCurrentPage() {
        return currentPage;
    }

    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }

    public int getRows() {
        return rows;
    }

    public void setRows(int rows) {
        this.rows = rows;
    }

    @Override
    public String toString() {
        return "PageBean{" +
                "totalCount=" + totalCount +
                ", totalPage=" + totalPage +
                ", list=" + list +
                ", currentPage=" + currentPage +
                ", rows=" + rows +
                '}';
    }
}

　　FinduserByPageServlet

package cn.itcast.web.servlet;

import cn.itcast.domain.PageBean;
import cn.itcast.domain.User;
import cn.itcast.service.UserService;
import cn.itcast.service.impl.UserServiceImpl;
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;

@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.获取参数
        String currentPage = request.getParameter("currentPage");
        String rows = request.getParameter("rows");
        //2.调用service查询
        UserService service = new UserServiceImpl();
        if(currentPage == null || currentPage.equals("")){
            currentPage = "1";
        }
        if(rows == null || rows.equals("")){
            rows = "5";
        }
        PageBean<User> pb = service.findUserByPage(currentPage,rows);
        System.out.println(pb);
        //3.将PageBean存入request
        request.setAttribute("pb",pb);
        //4.转发到list
        request.getRequestDispatcher("/list.jsp").forward(request,response);
    }

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

　　index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="zh-CN">
<head>
  <meta charset="utf-8"/>
  <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
  <meta name="viewport" content="width=device-width, initial-scale=1"/>
  <title>首页</title>

  <!-- 1. 导入CSS的全局样式 -->
  <link href="css/bootstrap.min.css" rel="stylesheet">
  <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
  <script src="js/jquery-2.1.0.min.js"></script>
  <!-- 3. 导入bootstrap的js文件 -->
  <script src="js/bootstrap.min.js"></script>
  <script type="text/javascript">
  </script>
</head>
<body>
<div>${user.name},欢迎您！</div>
<div align="center">
  <a
          href="${pageContext.request.contextPath}/findUserByPageServlet" style="text-decoration:none;font-size:33px">查询所有用户信息
  </a>
</div>
</body>
</html>

　　list.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
    <script>
        function deleteUser(id){
            //用户安全提示
            if(confirm("您确定要删除吗？")){
                //访问路径
                location.href = "${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }
        window.onload = function() {
            //给删除选中按钮添加单击事件
            document.getElementById("delSelected").onclick = function () {

                if(confirm("您确定要删除选中条目吗？")){
                    var flag = false;
                    //判断是否有选中条目
                    var cbs = document.getElementsByName("uid");
                    for (var i = 0; i < cbs.length; i++) {
                        if(cbs[i].checked){
                            flag = true;
                            break;
                        }
                    }
                    //有条目选中，表单提交
                    if(flag){
                        document.getElementById("form").submit();
                    }
                }
            }

            //全选全不选复选框功能
            //1.获取第一个cb
            document.getElementById("firstCb").onclick = function () {
                //2.获取下边列表中所有的cb
                var cbs = document.getElementsByName("uid");
                //3.遍历
                for (var i = 0; i < cbs.length; i++) {
                    //4.设置这些cbs[i]的checked状态=firstCb.checked
                    cbs[i].checked = this.checked;
                }
            }
        }
    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2">
            </div>
            <div class="form-group">
                <label for="exampleInputAddress2">籍贯</label>
                <input type="text" class="form-control" id="exampleInputAddress2">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail2">
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>


    <div style="float: right;margin: 5px">
        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="javascript:void(0);" id="delSelected">删除选中</a>
    </div>
    <form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
        <table border="1" class="table table-bordered table-hover">
            <tr class="success">
                <th><input type="checkbox" id="firstCb"></th>
                <th>编号</th>
                <th>姓名</th>
                <th>性别</th>
                <th>年龄</th>
                <th>籍贯</th>
                <th>QQ</th>
                <th>邮箱</th>
                <th>操作</th>
            </tr>
            <c:forEach items="${pb.list}" var="user" varStatus="s">
                <tr>
                    <td><input type="checkbox" name="uid" value="${user.id}"></td>
                    <td>${s.count}</td>
                    <td>${user.name}</td>
                    <td>${user.gendar}</td>
                    <td>${user.age}</td>
                    <td>${user.address}</td>
                    <td>${use.qq}</td>
                    <td>${user.email}</td>
                    <td>
                        <a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>&nbsp;
                        <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>
                    </td>
                </tr>
            </c:forEach>

        </table>
    </form>

    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <c:if test="${pb.currentPage == 1}">
                    <li class="disabled">
                </c:if>
                <c:if test="${pb.currentPage != 1}">
                    <li>
                </c:if>
                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage-1}&rows=${pb.rows}" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
                <c:forEach begin="1" end="${pb.totalPage}" var="i">
                    <c:if test="${pb.currentPage == i}">
                        <%--当前页码激活状态-选中--%>
                        <li class="active"><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=${pb.rows}">${i}</a></li>
                    </c:if>
                    <c:if test="${pb.currentPage != i}">
                        <li><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=${pb.rows}">${i}</a></li>
                    </c:if>
                </c:forEach>

                <c:if test="${pb.currentPage == pb.totalPage}">
                    <li class="disabled">
                </c:if>
                <c:if test="${pb.currentPage != pb.totalPage}">
                    <li>
                 </c:if>
                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage+1}&rows=${pb.rows}" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共${pb.totalCount}条记录，共${pb.totalPage}页
                </span>
            </ul>
        </nav>
    </div>
</div>
</body>
</html>

　　UserService.java

    /**
     * 分页查询
     * @param currentPage
     * @param rows
     * @return
     */
    PageBean<User> findUserByPage(String currentPage, String rows);

　　UserServiceImpl.java

　　@Override
    public PageBean<User> findUserByPage(String _currentPage, String _rows) {

        int currentPage = Integer.parseInt(_currentPage);
        int rows = Integer.parseInt(_rows);
        if(currentPage <= 0){
            currentPage = 1;
        }
        //1.创建空的PageBean对象
        PageBean<User> pb = new PageBean<User>();
        //2.设置参数
        pb.setRows(rows);
        //3.调用dao查询总记录数
        int totalCount = dao.findTotalCount();
        pb.setTotalCount(totalCount);
        int totalPage = (totalCount % rows) == 0 ? totalCount/rows:(totalCount/rows)+1;
        pb.setTotalPage(totalPage);
        if(currentPage >= totalPage){
            currentPage = totalPage;
        }
        pb.setCurrentPage(currentPage);
        //4.调用dao查询list集合
        //计算开始的记录索引
        int start = (currentPage-1) * rows;
        List<User> list = dao.findByPage(start,rows);
        pb.setList(list);
         return pb;
    }

　　UserDao.java

    /**
     * 查询总记录数
     * @return
     */
    public int findTotalCount();

    /**
     * 分页查询每页记录
     * @param start
     * @param rows
     * @return
     */
    List<User> findByPage(int start, int rows);

　　UserDaoImpl.java

    @Override
    public int findTotalCount() {
        String sql = "select count(*) from user";
        return template.queryForObject(sql,Integer.class);
    }

    @Override
    public List<User> findByPage(int start, int rows) {
        String sql = "select * from user limit ?,?";
        return template.query(sql,new BeanPropertyRowMapper<User>(User.class),start,rows);
    }

　　浏览器访问http://localhost/day18，然后进入列表页

　　　

　3、复杂条件查询 

　　

　　list.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
    <script>
        function deleteUser(id){
            //用户安全提示
            if(confirm("您确定要删除吗？")){
                //访问路径
                location.href = "${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }
        window.onload = function() {
            //给删除选中按钮添加单击事件
            document.getElementById("delSelected").onclick = function () {

                if(confirm("您确定要删除选中条目吗？")){
                    var flag = false;
                    //判断是否有选中条目
                    var cbs = document.getElementsByName("uid");
                    for (var i = 0; i < cbs.length; i++) {
                        if(cbs[i].checked){
                            flag = true;
                            break;
                        }
                    }
                    //有条目选中，表单提交
                    if(flag){
                        document.getElementById("form").submit();
                    }
                }
            }

            //全选全不选复选框功能
            //1.获取第一个cb
            document.getElementById("firstCb").onclick = function () {
                //2.获取下边列表中所有的cb
                var cbs = document.getElementsByName("uid");
                //3.遍历
                for (var i = 0; i < cbs.length; i++) {
                    //4.设置这些cbs[i]的checked状态=firstCb.checked
                    cbs[i].checked = this.checked;
                }
            }
        }
    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">
        <form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" class="form-control" id="exampleInputName2" name="name" value="${condition.name[0]}">
            </div>
            <div class="form-group">
                <label for="exampleInputAddress2">籍贯</label>
                <input type="text" class="form-control" id="exampleInputAddress2" name="address" value="${condition.address[0]}">
            </div>
            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="email" class="form-control" id="exampleInputEmail2" name="email" value="${condition.email[0]}">
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>
    </div>


    <div style="float: right;margin: 5px">
        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="javascript:void(0);" id="delSelected">删除选中</a>
    </div>
    <form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
        <table border="1" class="table table-bordered table-hover">
            <tr class="success">
                <th><input type="checkbox" id="firstCb"></th>
                <th>编号</th>
                <th>姓名</th>
                <th>性别</th>
                <th>年龄</th>
                <th>籍贯</th>
                <th>QQ</th>
                <th>邮箱</th>
                <th>操作</th>
            </tr>
            <c:forEach items="${pb.list}" var="user" varStatus="s">
                <tr>
                    <td><input type="checkbox" name="uid" value="${user.id}"></td>
                    <td>${s.count}</td>
                    <td>${user.name}</td>
                    <td>${user.gendar}</td>
                    <td>${user.age}</td>
                    <td>${user.address}</td>
                    <td>${use.qq}</td>
                    <td>${user.email}</td>
                    <td>
                        <a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>&nbsp;
                        <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id})">删除</a>
                    </td>
                </tr>
            </c:forEach>

        </table>
    </form>

    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <c:if test="${pb.currentPage == 1}">
                    <li class="disabled">
                </c:if>
                <c:if test="${pb.currentPage != 1}">
                    <li>
                </c:if>
                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage-1}&rows=${pb.rows}&name=${condition.name[0]}&&address=${condition.address[0]}&&email=${condition.email[0]}" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
                <c:forEach begin="1" end="${pb.totalPage}" var="i">
                    <c:if test="${pb.currentPage == i}">
                        <%--当前页码激活状态-选中--%>
                        <li class="active"><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=${pb.rows}&name=${condition.name[0]}&&address=${condition.address[0]}&&email=${condition.email[0]}">${i}</a></li>
                    </c:if>
                    <c:if test="${pb.currentPage != i}">
                        <li><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=${pb.rows}&name=${condition.name[0]}&&address=${condition.address[0]}&&email=${condition.email[0]}">${i}</a></li>
                    </c:if>
                </c:forEach>

                <c:if test="${pb.currentPage == pb.totalPage}">
                    <li class="disabled">
                </c:if>
                <c:if test="${pb.currentPage != pb.totalPage}">
                    <li>
                 </c:if>
                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage+1}&rows=${pb.rows}&name=${condition.name[0]}&&address=${condition.address[0]}&&email=${condition.email[0]}" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px">
                    共${pb.totalCount}条记录，共${pb.totalPage}页
                </span>
            </ul>
        </nav>
    </div>
</div>
</body>
</html>

　　FindUserByPageServlet

@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        //1.获取参数
        String currentPage = request.getParameter("currentPage");
        String rows = request.getParameter("rows");
        //2.调用service查询
        UserService service = new UserServiceImpl();
        if(currentPage == null || currentPage.equals("")){
            currentPage = "1";
        }
        if(rows == null || rows.equals("")){
            rows = "5";
        }
        //获取条件查询参数
        Map<String, String[]> condition = request.getParameterMap();
       PageBean<User> pb = service.findUserByPage(currentPage,rows,condition);
        System.out.println(pb);
        //3.将PageBean存入request
        request.setAttribute("pb",pb);
        //将查询条件存入request
       request.setAttribute("condition",condition);
        //4.转发到list
        request.getRequestDispatcher("/list.jsp").forward(request,response);
    }

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

　　UserService

    /**
     * 分页查询 & 分页条件查询
     * @param currentPage
     * @param rows
     * @param condition
     * @return
     */
    PageBean<User> findUserByPage(String currentPage, String rows, Map<String, String[]> condition);

　　UserServiceImpl

    @Override
    public PageBean<User> findUserByPage(String _currentPage, String _rows, Map<String, String[]> condition) {

        int currentPage = Integer.parseInt(_currentPage);
        int rows = Integer.parseInt(_rows);
        if(currentPage <= 0){
            currentPage = 1;
        }
        //1.创建空的PageBean对象
        PageBean<User> pb = new PageBean<User>();
        //2.设置参数
        pb.setRows(rows);
        //3.调用dao查询总记录数
        int totalCount = dao.findTotalCount(condition);
        pb.setTotalCount(totalCount);
        int totalPage = (totalCount % rows) == 0 ? totalCount/rows:(totalCount/rows)+1;
        pb.setTotalPage(totalPage);
        if(currentPage >= totalPage){
            currentPage = totalPage;
        }
        pb.setCurrentPage(currentPage);
        //4.调用dao查询list集合
        //计算开始的记录索引
        int start = (currentPage-1) * rows;
        List<User> list = dao.findByPage(start,rows,condition);
        pb.setList(list);
         return pb;
    }

　　UserDao

    /**
     * 查询总记录数
     * @return
     * @param condition
     */
    public int findTotalCount(Map<String, String[]> condition);

    /**
     * 分页查询每页记录
     * @param start
     * @param rows
     * @param condition
     * @return
     */
    List<User> findByPage(int start, int rows, Map<String, String[]> condition);

　　UserDaoImpl

    @Override
    public int findTotalCount(Map<String, String[]> condition) {
        //1.定义模板初始化sql
        String sql = "select count(*) from user where 1 = 1";
        StringBuilder sb = new StringBuilder(sql);
        //2.遍历map
        Set<String> keySet = condition.keySet();
        //定义参数的集合
        List<Object> params = new ArrayList<Object>();
        for (String key : keySet) {
            //排除分页条件参数
            if("currentPage".equals(key) || "rows".equals(key)){
                continue;
            }
            //获取value
            String value = condition.get(key)[0];
            //判断value是否有值
            if(value != null && !value.equals("")){
                sb.append(" and "+key+" like ? ");
                params.add("%"+value+"%");//?条件的值
            }
        }
        System.out.println(sb.toString());
        System.out.println(params);
        return template.queryForObject(sb.toString(),Integer.class,params.toArray());
    }

    @Override
    public List<User> findByPage(int start, int rows, Map<String, String[]> condition) {
        String sql = "select * from user where 1 =1";
        StringBuilder sb = new StringBuilder(sql);
        Set<String> keySet = condition.keySet();
        List<Object> params = new ArrayList<Object>();
        for (String key : keySet) {
            if("currentPage".equals(key) || "rows".equals(key)){
                continue;
            }
            String value = condition.get(key)[0];
            if(value != null && !value.equals("")){
                sb.append(" and "+key+" like ? ");
                params.add("%"+value+"%");//?条件的值
            }
        }
        //添加分页
        sb.append(" limit ?,? ");
        //添加分页查询参数值
        params.add(start);
        params.add(rows);
        System.out.println(sb.toString());
        System.out.println(params);
        return template.query(sb.toString(),new BeanPropertyRowMapper<User>(User.class),params.toArray());
    }

　　浏览器访问http://localhost/day18，然后进入列表页，根据条件查询

　　　

 

posted on 2024-06-14 19:47  花溪月影  阅读(3)  评论(0)  编辑  收藏  举报

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