Java--小項目（登陸、增刪改查、分頁、搜索）
博客說明javascript
文章所涉及的資料來自互聯網整理和我的總結，意在於我的學習和經驗彙總，若有什麼地方侵權，請聯繫本人刪除，謝謝！css
概念
技術選型
Servlet、JSP、MySQL、JDBCTempleat、Duird、BeanUtilS、tomcathtml
功能介紹
登陸功能，列表展現，數據添加，數據編輯，數據刪除，批量刪除，分頁展現，關鍵字搜索java
建立JavaWeb項目
導入依賴
添加頁面文件
數據庫
create database little; -- 建立數據庫 use little; -- 使用數據庫 create table user( -- 建立表 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, username varchar(32), password varchar(32), );
列表展現
思路
首先咱們須要一組列表的數據，那麼咱們就須要一個相對應servlet，經過咱們的三層架構，使用service同一作接口，而後調用dao層使用JBDC操做數據庫，這樣咱們能夠得到一個map集合的數據，而後就是渲染數據到jsp頁面了，經過JSTL和EL把數據循環渲染到表裏面，達到列表的展現jquery
list.jsp
<%--
Created by IntelliJ IDEA.
User: tanglei
Date: 2020/6/28
Time: 下午2:15
To change this template use File | Settings | File Templates.
--%>
<%@ 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">
<!-- 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：網頁能夠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，任何其餘內容都*必須*跟隨其後！ -->
<title>用戶信息管理系統</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>
<style type="text/css">
td, th {
text-align: center;
}
</style>
</head>
<body>
<div class="container">
<h3 style="text-align: center">用戶信息列表</h3>
<table border="1" class="table table-bordered table-hover">
<tr class="success">
<th>編號</th>
<th>姓名</th>
<th>性別</th>
<th>年齡</th>
<th>籍貫</th>
<th>QQ</th>
<th>郵箱</th>
<th>操做</th>
</tr>
<c:forEach items="${users}" var="user" varStatus="s">
<tr>
<td>${s.count}</td>
<td>${user.name}</td>
<td>${user.gender}</td>
<td>${user.age}</td>
<td>${user.address}</td>
<td>${user.qq}</td>
<td>${user.email}</td>
<td><a class="btn btn-default btn-sm" href="update.html">修改</a> <a class="btn btn-default btn-sm"
href="">刪除</a></td>
</tr>
</c:forEach>
<tr>
<td colspan="8" align="center"><a class="btn btn-primary" href="add.html">添加聯繫人</a></td>
</tr>
</table>
</div>
</body>
</html>
servlet
代碼文件不少，就不一一展現了程序員
UserListServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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.List;
@WebServlet("/userListServlet")
public class UserListServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//調用UserService完成查詢
UserService userService = new UserServiceImpl();
List<User> users = userService.findAll();
//存入request域
req.setAttribute("users",users);
//轉發到list.jsp
req.getRequestDispatcher("/list.jsp").forward(req,resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測試
登陸
思路
登陸功能首先就是對錶單提交的數據進行比對，驗證碼能夠在生成的時候就把它存入到session中，而後在servlet中進行比對，其餘的字段在經過調用dao層的JDBC操做數據庫進行比對，最後把登陸成功的用戶信息存入session中web
login.jsp
<%--
Created by IntelliJ IDEA.
User: tanglei
Date: 2020/6/28
Time: 下午7:37
To change this template use File | Settings | File Templates.
--%>
<%@ 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>管理員登陸</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">
function refreshCode() {
let vcode = document.getElementById("vcode");
vcode.src = "${pageContext.request.contextPath}/checkCodeServlet?=" + new Date().getTime();
}
</script>
</head>
<body>
<div class="container" style="width: 400px;">
<h3 style="text-align: center;">管理員登陸</h3>
<form action="${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="${pageContext.request.contextPath}/checkCodeServlet"
title="看不清點擊刷新" id="vcode"/></a>
</div>
<hr/>
<div class="form-group" style="text-align: center;">
<input class="btn btn btn-primary" type="submit" value="登陸">
</div>
</form>
<!-- 出錯顯示的信息框 -->
<div class="alert alert-warning alert-dismissible" role="alert">
<button type="button" class="close" data-dismiss="alert">
<span>×</span></button>
<strong>${login_msg}</strong>
</div>
</div>
</body>
</html>
LoginServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//設置編碼
req.setCharacterEncoding("utf-8");
//傳遞過來的驗證碼
String verifycode = req.getParameter("verifycode");
HttpSession session = req.getSession();
//session裏面的驗證碼
String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
session.removeAttribute("CHECKCODE_SERVER");
//比對驗證碼
if (!checkcode_server.equalsIgnoreCase(verifycode)) {
req.setAttribute("login_msg", "驗證碼錯誤");
req.getRequestDispatcher("/login.jsp").forward(req, resp);
return;
}
Map<String, String[]> parameterMap = req.getParameterMap();
User user = new User();
try {
BeanUtils.populate(user, parameterMap);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
UserService userService = new UserServiceImpl();
User loginUser = userService.login(user);
if(loginUser != null){
session.setAttribute("user",loginUser);
resp.sendRedirect(req.getContextPath()+"/index.jsp");
}else {
req.setAttribute("login_msg", "登陸失敗");
req.getRequestDispatcher("/login.jsp").forward(req, resp);
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
CheckCodeServlet
package cn.guizimo.little.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;
/**
* 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");
//在內存中建立一個長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);
}
}
測試
添加人員
思路
添加操做就是把jsp提交的表單的數據向數據庫裏面存儲，過程爲jsp->servlet->service->daosql
add.jsp
<%--
Created by IntelliJ IDEA.
User: tanglei
Date: 2020/6/28
Time: 下午8:55
To change this template use File | Settings | File Templates.
--%>
<%@ 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：網頁能夠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，任何其餘內容都*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="jiguan">
<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" 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" 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>
</html>
AddUserServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
Map<String, String[]> parameterMap = req.getParameterMap();
User user = new User();
try {
BeanUtils.populate(user,parameterMap);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
UserService userService = new UserServiceImpl();
userService.addUser(user);
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測試
修改
思路
首先咱們須要在打開jsp頁面的時候就查詢到這樣的一條記錄，經過這一條記錄的id做爲表單的隱藏域，在servlet裏面將數據進行保存便可數據庫
update.jsp
<%--
Created by IntelliJ IDEA.
User: tanglei
Date: 2020/6/29
Time: 上午10:44
To change this template use File | Settings | File Templates.
--%>
<%@ 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">
<!-- 隱藏域 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="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" value="${user.age}" id="age" name="age" placeholder="請輸入年齡" />
</div>
<div class="form-group">
<label for="address">籍貫：</label>
<select name="address" id="address" class="form-control" >
<c:if test="${user.address == '陝西'}">
<option value="陝西" selected>陝西</option>
<option value="北京">北京</option>
<option value="上海">上海</option>
</c:if>
<c:if test="${user.address == '北京'}">
<option value="陝西" >陝西</option>
<option value="北京" selected>北京</option>
<option value="上海">上海</option>
</c:if>
<c:if test="${user.address == '上海'}">
<option value="陝西" >陝西</option>
<option value="北京">北京</option>
<option value="上海" selected>上海</option>
</c:if>
</select>
</div>
<div class="form-group">
<label for="qq">QQ：</label>
<input type="text" id="qq" class="form-control" value="${user.qq}" name="qq" placeholder="請輸入QQ號碼"/>
</div>
<div class="form-group">
<label for="email">Email：</label>
<input type="text" id="email" class="form-control" value="${user.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" />
<a class="btn btn-default" href="${pageContext.request.contextPath}/userListServlet">返回</a>
</div>
</form>
</div>
</body>
</html>
FindUserServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.獲取id
String id = req.getParameter("id");
//2.調用Service查詢
UserService service = new UserServiceImpl();
User user = service.findUserById(id);
//3.將user存入request
req.setAttribute("user",user);
//4.轉發到update.jsp
req.getRequestDispatcher("/update.jsp").forward(req,resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
UpdateUserServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.設置編碼
req.setCharacterEncoding("utf-8");
//2.獲取map
Map<String, String[]> map = req.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.跳轉到查詢全部Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測試
刪除
思路
經過獲取到對應的id便可到servlet中處理，操做數據庫刪除，在進行刪除的時候可出現提示框apache
DelUserServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.獲取id
String id = req.getParameter("id");
//2.調用service刪除
UserService service = new UserServiceImpl();
service.deleteUser(id);
//3.跳轉到查詢全部Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測試
刪除選擇的多個
思路
和刪除差很少，最主要是獲取id的集合
DelSelectedServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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 {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.獲取全部id
String[] ids = req.getParameterValues("uid");
//2.調用service刪除
UserService service = new UserServiceImpl();
service.delSelectedUser(ids);
//3.跳轉查詢全部Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測試
分頁
思路
在jsp中獲取查詢的總條數，每頁顯示的條數，當前的頁碼，將之傳遞給服務器，操做數據庫進行查詢
list.jsp
<%--
Created by IntelliJ IDEA.
User: tanglei
Date: 2020/6/28
Time: 下午2:15
To change this template use File | Settings | File Templates.
--%>
<%@ 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">
<!-- 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：網頁能夠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，任何其餘內容都*必須*跟隨其後！ -->
<title>用戶信息管理系統</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>
<style type="text/css">
td, th {
text-align: center;
}
</style>
<script>
function deleteUser(id) {
//用戶安全提示
if (confirm("您肯定要刪除嗎？")) {
//訪問路徑
location.href = "${pageContext.request.contextPath}/delUserServlet?id=" + id;
}
}
window.onload = function () {
//給刪除選中按鈕添加單擊事件
document.getElementById("delSelected").onclick = function () {
if (confirm("您肯定要刪除選中條目嗎？")) {
var flag = false;
//判斷是否有選中條目
var cbs = document.getElementsByName("uid");
for (var i = 0; i < cbs.length; i++) {
if (cbs[i].checked) {
//有一個條目選中了
flag = true;
break;
}
}
if (flag) {//有條目被選中
//表單提交
document.getElementById("form").submit();
}
}
}
//1.獲取第一個cb
document.getElementById("firstCb").onclick = function () {
//2.獲取下邊列表中全部的cb
var cbs = document.getElementsByName("uid");
//3.遍歷
for (var i = 0; i < cbs.length; i++) {
//4.設置這些cbs[i]的checked狀態 = firstCb.checked
cbs[i].checked = this.checked;
}
}
}
</script>
</head>
<body>
<div class="container">
<h3 style="text-align: center">用戶信息列表</h3>
<div style="float: left;">
<form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
<div class="form-group">
<label for="exampleInputName2">姓名</label>
<input type="text" name="name" value="${condition.name[0]}" class="form-control" id="exampleInputName2">
</div>
<div class="form-group">
<label for="exampleInputName3">籍貫</label>
<input type="text" name="address" value="${condition.address[0]}" class="form-control"
id="exampleInputName3">
</div>
<div class="form-group">
<label for="exampleInputEmail2">郵箱</label>
<input type="text" name="email" value="${condition.email[0]}" class="form-control"
id="exampleInputEmail2">
</div>
<button type="submit" class="btn btn-default">查詢</button>
</form>
</div>
<div style="float: right;margin: 5px;">
<a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加聯繫人</a>
<a class="btn btn-primary" href="javascript:void(0);" id="delSelected">刪除選中</a>
</div>
<form id="form" action="${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>編號</th>
<th>姓名</th>
<th>性別</th>
<th>年齡</th>
<th>籍貫</th>
<th>QQ</th>
<th>郵箱</th>
<th>操做</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>${user.gender}</td>
<td>${user.age}</td>
<td>${user.address}</td>
<td>${user.qq}</td>
<td>${user.email}</td>
<td>
<a class="btn btn-default btn-sm"
href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>
<a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id});">刪除</a>
</td>
</tr>
</c:forEach>
</table>
</form>
<div>
<nav aria-label="Page navigation">
<ul class="pagination">
<c:if test="${pb.currentPage == 1}">
<li class="disabled">
<a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=1&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}"
aria-label="Previous">
<span aria-hidden="true">«</span>
</a>
</li>
</c:if>
<c:if test="${pb.currentPage != 1}">
<li>
<a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage - 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}"
aria-label="Previous">
<span aria-hidden="true">«</span>
</a>
</li>
</c:if>
<c:forEach begin="1" end="${pb.totalPage}" var="i">
<c:if test="${pb.currentPage == i}">
<li class="active"><a
href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${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=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a>
</li>
</c:if>
</c:forEach>
<c:if test="${pb.currentPage == pb.totalPage}">
<li class="disabled">
<a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.totalPage}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}"
aria-label="Next">
<span aria-hidden="true">»</span>
</a>
</li>
</c:if>
<c:if test="${pb.currentPage != pb.totalPage}">
<li>
<a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage + 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}"
aria-label="Next">
<span aria-hidden="true">»</span>
</a>
</li>
</c:if>
<span style="font-size: 25px;margin-left: 5px;">
共${pb.totalCount}條記錄，共${pb.totalPage}頁
</span>
</ul>
</nav>
</div>
</div>
</body>
</html>
FindUserByPageServlet
package cn.guizimo.little.web.servlet;
import cn.guizimo.little.domain.PageBean;
import cn.guizimo.little.domain.User;
import cn.guizimo.little.service.UserService;
import cn.guizimo.little.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);
//3.將PageBean存入request
request.setAttribute("pb",pb);
request.setAttribute("condition",condition);//將查詢條件存入request
//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);
}
}
測試
條件查詢
思路
主要是在sql語句的編寫
jsp
<div style="float: left;">
<form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
<div class="form-group">
<label for="exampleInputName2">姓名</label>
<input type="text" name="name" value="${condition.name[0]}" class="form-control" id="exampleInputName2">
</div>
<div class="form-group">
<label for="exampleInputName3">籍貫</label>
<input type="text" name="address" value="${condition.address[0]}" class="form-control"
id="exampleInputName3">
</div>
<div class="form-group">
<label for="exampleInputEmail2">郵箱</label>
<input type="text" name="email" value="${condition.email[0]}" class="form-control"
id="exampleInputEmail2">
</div>
<button type="submit" class="btn btn-default">查詢</button>
</form>
</div>
dao層方法
@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();
//定義參數的集合
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());
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);
//2.遍歷map
Set<String> keySet = condition.keySet();
//定義參數的集合
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 ?,? ");
//添加分頁查詢參數值
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());
}
測試
感謝
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