今日內容

用戶信息列表展示

簡單功能
1. 列表查詢
2. 登錄
3. 添加
4. 刪除
5. 修改
複雜功能
1. 刪除選中
2. 分頁查詢
- 好處：
  1. 減輕服務器內存的開銷
  2. 提升用戶體驗
1. 複雜條件查詢

涉及相關技術：Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat

今日源碼：
鏈接：https://pan.baidu.com/s/1TrgVXlXn6cYG3Jz1-Y_bFQ
提取碼：e9de

案例：用戶信息列表展示

1. 需求：用戶信息的增刪改查操作

目標：完成下圖中的所有功能

2. 設計：

1. 技術選型：

Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat

2. 數據庫設計：

create database day17; -- 創建數據庫
use day17; 			   -- 使用數據庫
create table user(   -- 創建表
	id int primary key auto_increment,
	name varchar(20) not null,
	gender varchar(5),
	age int,
	address varchar(32),
	qq	varchar(20),
	email varchar(50)
);

3. 開發：

1. 環境搭建

創建數據庫環境
創建項目，導入需要的jar包

2. 編碼

2.1登錄功能

效果：

測試：輸入錯誤驗證碼效果

輸入錯誤賬戶密碼：

代碼：

登錄界面代碼： login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<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>管理員登錄</title>
    <!-- 1. 導入CSS的全局樣式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery導入，建議使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 導入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <script type="text/javascript">
    </script>
    <script>
        window.onload = function(){
            document.getElementById("vcode").onclick = function(){
                this.src="${pageContext.request.contextPath}/checkCodeServlet?time="+new Date().getTime();
            }
        }
    </script>
</head>
<body>
<div class="container" style="width: 400px;">
    <h3 style="text-align: center;">管理員登錄</h3>
    <form action="${pageContext.request.contextPath}/loginServlet" method="post">
        <div class="form-group">
            <label for="user">用戶名：</label>
            <input type="text" name="username" class="form-control" id="user" placeholder="請輸入用戶名"/>
        </div>

        <div class="form-group">
            <label for="password">密碼：</label>
            <input type="password" name="password" class="form-control" id="password" placeholder="請輸入密碼"/>
        </div>

        <div class="form-inline">
            <label for="vcode">驗證碼：</label>
            <input type="text" name="verifycode" class="form-control" id="verifycode" placeholder="請輸入驗證碼" style="width: 120px;"/>
            <a href="javascript:refreshCode();">
                <img src="${pageContext.request.contextPath}/checkCodeServlet" title="看不清點擊刷新" id="vcode"/>
            </a>

        </div>
        <hr/>
        <div class="form-group" style="text-align: center;">
            <input class="btn btn btn-primary" type="submit" value="登錄">
        </div>
    </form>

    <!-- 出錯顯示的信息框 -->
    <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>

驗證碼校驗Servlet： CheckCodeServlet.java

package cn.wbslz.web.servlet;

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;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

/**
 * 驗證碼
 */
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
		//服務器通知瀏覽器不要緩存
		response.setHeader("pragma","no-cache");
		response.setHeader("cache-control","no-cache");
		response.setHeader("expires","0");
		
		//在內存中創建一個長80，寬30的圖片，默認黑色背景
		//參數一：長
		//參數二：寬
		//參數三：顏色
		int width = 80;
		int height = 30;
		BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
		
		//獲取畫筆
		Graphics g = image.getGraphics();
		//設置畫筆顏色爲灰色
		g.setColor(Color.GRAY);
		//填充圖片
		g.fillRect(0,0, width,height);
		
		//產生4個隨機驗證碼，12Ey
		String checkCode = getCheckCode();
		//將驗證碼放入HttpSession中
		request.getSession().setAttribute("CHECKCODE_SERVER",checkCode);
		
		//設置畫筆顏色爲黃色
		g.setColor(Color.YELLOW);
		//設置字體的小大
		g.setFont(new Font("黑體",Font.BOLD,24));
		//向圖片上寫入驗證碼
		g.drawString(checkCode,15,25);
		
		//將內存中的圖片輸出到瀏覽器
		//參數一：圖片對象
		//參數二：圖片的格式，如PNG,JPG,GIF
		//參數三：圖片輸出到哪裏去
		ImageIO.write(image,"PNG",response.getOutputStream());
	}
	/**
	 * 產生4位隨機字符串 
	 */
	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++){
			//產生0到size-1的隨機值
			int index = r.nextInt(size);
			//在base字符串中獲取下標爲index的字符
			char c = base.charAt(index);
			//將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);
	}
}

2.2 歡迎界面

代碼
index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<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>首頁</title>

  <!-- 1. 導入CSS的全局樣式 -->
  <link href="css/bootstrap.min.css" rel="stylesheet">
  <!-- 2. jQuery導入，建議使用1.9以上的版本 -->
  <script src="js/jquery-2.1.0.min.js"></script>
  <!-- 3. 導入bootstrap的js文件 -->
  <script src="js/bootstrap.min.js"></script>
  <script type="text/javascript">
  </script>
</head>
<body>

  <div>${user.name},歡迎您！</div>

<div align="center">
  <a
    href="${pageContext.request.contextPath}/findUserByPageServlet" style="text-decoration:none;font-size:33px">查詢所有用戶信息
  </a>
</div>
</body>
</html>

2.3查詢結果界面

效果：

2.4 添加用戶功能

分析

編碼：

add.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!-- HTML5文檔-->
<!DOCTYPE html>
<!-- 網頁使用的語言 -->
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的瀏覽器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport視口：網頁可以根據設置的寬度自動進行適配，在瀏覽器的內部虛擬一個容器，容器的寬度與設備的寬度相同。
    width: 默認寬度與設備的寬度相同
    initial-scale: 初始的縮放比，爲1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3個meta標籤*必須*放在最前面，任何其他內容都*必須*跟隨其後！ -->
    <title>添加用戶</title>

    <!-- 1. 導入CSS的全局樣式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery導入，建議使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 導入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <center><h3>添加聯繫人頁面</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="請輸入姓名">
        </div>

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

        <div class="form-group">
            <label for="age">年齡：</label>
            <input type="text" class="form-control" id="age" name="age" placeholder="請輸入年齡">
        </div>

        <div class="form-group">
            <label for="address">籍貫：</label>
            <select name="address" class="form-control" id="address">
                <option value="廣東">廣東</option>
                <option value="廣西">廣西</option>
                <option value="湖南">湖南</option>
            </select>
        </div>

        <div class="form-group">
            <label for="qq">QQ：</label>
            <input type="text" class="form-control" id="qq" name="qq" placeholder="請輸入QQ號碼"/>
        </div>

        <div class="form-group">
            <label for="email">Email：</label>
            <input type="text" class="form-control" id="email" name="email" placeholder="請輸入郵箱地址"/>
        </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>

AddUserServlet

package cn.wbslz.web.servlet;

import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.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設置編碼
        request.setCharacterEncoding("utf-8");
        //2.獲取參數
        Map<String, String[]> map = request.getParameterMap();
        //3.封裝對象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //4.調用service保存
        UserService service = new UserServiceImpl();
        service.addUser(user);
        //5.跳轉到userListServlet
        response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

UserService接口

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

UserServiceImpl實現類

private UserDao dao = new UserDaoImpl();
@Override
    public void addUser(User user) {
        dao.add(user);
    }

UserDao接口

    /**
     * 添加用戶
     * @param user
     */
    void add(User user);

UserDaoImpl實現類

    @Override
    public void add(User user) {
        //1 定義sql
        String sql = "insert into user values(null,?,?,?,?,?,?,null,null)";
        //2執行sql
        template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail());
        
    }

界面效果：

2.5 刪除功能

分析：
編碼：

delUserServlet

package cn.wbslz.web.servlet;

import cn.wbslz.service.UserService;
import cn.wbslz.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("/delUserServlet")
public class DelUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1 獲取id
        String id = request.getParameter("id");
        //2 調用service刪除
        UserService service = new UserServiceImpl();
        service.deleteUser(id);
        //3 跳轉到查詢所有頁面
		response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

UserService接口

 /**
     * 根據id刪除user
     * @param id
     */
    void deleteUser(String id);

UserServiceImpl實現類

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

UserDao接口

/**
 * 刪除用戶
 * @param id
 */
void delete(int id);

UserDaoImpl實現類

 @Override
 public void delete(int id) {
     //1 定義sql
     String sql = "delete from user where id = ?";
     //2.執行
     template.update(sql,id);
 }

演示效果：

2.6 修改功能

分析
編碼：

FindUserServlet

package cn.wbslz.web.servlet;

import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.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("/findUserServlet")
public class FindUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.獲取id
        String id = request.getParameter("id");
        //2.調用service
        UserService service = new UserServiceImpl();
        User user = service.findUserById(id);
        //3.將user存入request
        request.setAttribute("user",user);
        //4.轉發到update.jsp
request.getRequestDispatcher("/update.jsp").forward(request,response);

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

Update.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<!-- 網頁使用的語言 -->
<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>修改用戶</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;">修改聯繫人</h3>
    <form action="${pageContext.request.contextPath}/updateUserServlet" method="post">

        <input type="hidden" name="id" value="${user.id}"><%--隱藏域，傳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="請輸入姓名" />
        </div>

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

                <c:if test="${user.gender == '女' }">
                    <input type="radio" name="gender" value="男"  />男
                    <input type="radio" name="gender" value="女" checked />女
                </c:if>
        </div>

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

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

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

        <div class="form-group">
            <label for="email">Email：</label>
            <input type="text" class="form-control" id="email" name="email" value="${user.email}" placeholder="請輸入郵箱地址"/>
        </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

package cn.wbslz.web.servlet;

import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.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("/updateUserServlet")
public class UpdateUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1，設置編碼
        request.setCharacterEncoding("utf-8");
        //2.獲取map
        Map<String, String[]> map = request.getParameterMap();
        //3.封裝對象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //4.調用service修改
        UserService service = new UserServiceImpl();
        service.updateUser(user);
        //5.跳轉到查詢所有Servlet
       response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
    }

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

UserService接口

 /**
     *根據id查詢
     * @param id
     * @return
     */
    User findUserById(String id);

    /**
     * 修改用戶信息
     * @param user
     */
    void updateUser(User user);

UserServiceImpl實現類

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

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

UserDao接口

    /**
     * 根據id查詢用戶
     * @param id
     * @return
     */
    User findById(int id);

    /**
     * 修改用戶
     * @param user
     */
    void update(User user);

UserDaoImpl實現類

@Override
public User findById(int id) {
    //1定義sql
    String sql = "select * from user where id = ?";
    //2.執行
    return template.queryForObject(sql,new BeanPropertyRowMapper<User>(User.class),id);
}

@Override
public void update(User user) {
    //1定義sql
    String sql = "update user set name = ?,gender = ?,age = ?, address = ?,qq = ?,email = ? where id = ?";
    //2.執行
    template.update(sql,user.getName(),user.getGender(),user.getAge(),user.getAddress(),user.getQq(),user.getEmail(),user.getId());
}

效果演示

2.7 刪除選中功能

分析
編碼：

delSelectedServlet

package cn.wbslz.web.servlet;

import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.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("/delSelectedServlet")
public class DelSelectedServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //獲取所有id
        String[] ids = request.getParameterValues("uid");
        //2.調用service刪除
        UserService service = new UserServiceImpl();
        service.delSelectedUser(ids);
        //3.跳轉到查詢所有Servlet
        response.sendRedirect(request.getContextPath()+"/findUserByPageServlet");
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

UserService接口

/**
 * 批量刪除用戶
 * @param ids
 * @return
 */
void delSelectedUser(String[] ids);

UserServiceImpl實現類: 這裏循環複用刪除單個用戶方法

@Override
public void delSelectedUser(String[] ids) {
    if(ids != null && ids.length>0){
        //1.遍歷數組
        for(String id: ids){
            //2.調用dao刪除
            dao.delete(Integer.parseInt(id));
        }
    }
}

UserDao接口

/**
 * 刪除用戶
 * @param id
 */
void delete(int id);

UserDaoImpl實現類

   @Override
    public void delete(int id) {
        //1 定義sql
        String sql = "delete from user where id = ?";
        //2.執行
        template.update(sql,id);
    }

效果演示

2.8 分頁查詢功能（重點）

分析
編碼：

FindUserByPageServlet

package cn.wbslz.web.servlet;

import cn.wbslz.domain.PageBean;
import cn.wbslz.domain.User;
import cn.wbslz.service.UserService;
import cn.wbslz.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;
import java.util.Map;

@WebServlet("/findUserByPageServlet")
public class FindUserByPageServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        //1.獲取參數
        String currentPage = request.getParameter("currentPage");//當前頁碼
        String rows = request.getParameter("rows");//每頁顯示條數

        if(currentPage == null || "".equals(currentPage)){
            currentPage = "1";
        }
        if(rows == null || "".equals(rows)){
            rows = "5";
        }
        //獲取條件查詢的參數
        Map<String, String[]> condition = request.getParameterMap();
        //2.調用service查詢
        UserService service = new UserServiceImpl();
        PageBean<User> pb = service.findUserByPage(currentPage,rows,condition);
        System.out.println(pb);//測試用
        //3.將PageBean出入request
        request.setAttribute("pb",pb);
        request.setAttribute("condition",condition);//將查詢條件也存入
        //4.轉發到list.jsp
       request.getRequestDispatcher("/list.jsp").forward(request,response);
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

UserService接口

 /**
     * 分頁條件查詢
     * @param currentPage
     * @param rows
     * @param condition
     * @return
     */
    PageBean<User> findUserByPage(String currentPage, String rows, Map<String, String[]> condition);
}

UserServiceImpl實現類

@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){//當前頁小於0，則設置爲1
            currentPage = 1;
        }
        //1.創建空的PageBean對象
        PageBean<User> pb = new PageBean<User>();
        //2.調用dao查詢總記錄數
        int totalCount = dao.findTotalCount(condition);
        pb.setTotalCount(totalCount);
        //3.設置參數
        pb.setCurrentPage(currentPage);
        pb.setRows(rows);
        //4.計算總頁碼
        int totalPage = (totalCount % rows) == 0 ? (totalCount/rows) : (totalCount/rows) +1;
        pb.setTotalPage(totalPage);

        if(currentPage >= totalPage){//當前頁大於最大頁，則設置爲totalCount
            currentPage = totalPage;
        }
        //5.調用dao查詢List集合
        //計算開始的記錄
        int start = (currentPage - 1) * rows;
        List<User> list = dao.findByPage(start,rows,condition);
        pb.setList(list);
        return pb;
    }

UserDao接口

/**
 * 查詢總記錄數
 * @return
 * @param condition
 */
int findTotalCount(Map<String, String[]> condition);

/**
 * 分頁查詢每頁記錄
 * @param start
 * @param rows
 * @param condition
 * @return
 */
List<User> findByPage(int start, int rows, Map<String, String[]> condition);

UserDaoImpl實現類

@Override
    public int findTotalCount(Map<String, String[]> condition) {
        //1.定義模板初始化sql,
        String sql = "select count(*) from user where 1=1 ";
        StringBuilder sb = new StringBuilder(sql);
        //2.遍歷map
        Set<String> keySet = condition.keySet();
        //定義參數集合
        List<Object> params = new ArrayList<Object>();

        for(String key : keySet){

            //排除分頁條件參數
            if("currentPage".equals(key) || "rows".equals(key)){
                continue;
            }

            //獲取value
            String value = condition.get(key)[0];
            //判斷value是否有值
            if(value != null && !"".equals(value)){
                //有值
                sb.append(" and "+key+" like ? ");
                params.add("%"+value+"%");//？條件的值
            }
        }
        System.out.println(sb.toString());//測試
        System.out.println(params);//測試


        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);
        //2.遍歷map
        Set<String> keySet = condition.keySet();
        //定義參數集合
        List<Object> params = new ArrayList<Object>();

        for(String key : keySet){

            //排除分頁條件參數
            if("currentPage".equals(key) || "rows".equals(key)){
                continue;
            }

            //獲取value
            String value = condition.get(key)[0];
            //判斷value是否有值
            if(value != null && !"".equals(value)){
                //有值
                sb.append(" and "+key+" like ? ");
                params.add("%"+value+"%");//？條件的值
            }
        }

        //添加分頁查詢
        sb.append(" limit ?,? ");
        //添加分頁查詢參數
        params.add(start);
        params.add(rows);

        sql = sb.toString();
        System.out.println(sql);
        System.out.println(params);

        return template.query(sql,new BeanPropertyRowMapper<User>(User.class),params.toArray());
    }

效果：

2.9 複雜條件分頁查詢功能（重點）

分析：
編碼：
- 包含在2.9分頁查詢裏
效果

可以在控制檯查看到，查詢sql是動態變化的

4. 測試

略

5. 部署運維

使用tomcat服務器項目

6. 總結

該項目是融合了從前40天所學內容的整合項目，是對之前所學知識的實踐性檢驗，對訓練基礎知識很有幫助。

（[點開我的主頁系統的學習java]）

day41 JavaWeb階段——綜合案例:用戶信息列表展示（Servlet+JSP+MySQL+JDBCTempleat+Duird+BeanUtilS+tomcat完成用戶信息列表展示）