Java--小專案（登錄、增刪改查、分頁、搜索）
博客說明
文章所涉及的資料來自互聯網整理和個人總結，意在于個人學習和經驗匯總，如有什么地方侵權，請聯系本人洗掉，謝謝！
概念
技術選型
Servlet、JSP、MySQL、JDBCTempleat、Duird、BeanUtilS、tomcat
功能介紹
登錄功能，串列展示，資料添加，資料編輯，資料洗掉，批量洗掉，分頁展示，關鍵字搜索
創建JavaWeb專案
匯入依賴
添加頁面檔案
資料庫
create database little; -- 創建資料庫
use little; -- 使用資料庫
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,
username varchar(32),
password varchar(32),
);
串列展示
思路
首先我們需要一組串列的資料，那么我們就需要一個相對應servlet，通過我們的三層架構，使用service同一做介面，然后呼叫dao層使用JBDC操作資料庫，這樣我們可以獲得一個map集合的資料，然后就是渲染資料到jsp頁面了，通過JSTL和EL把資料回圈渲染到表里面，達到串列的展示
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：網頁可以根據設定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，為1:1 -->
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- 上述3個meta標簽*必須*放在最前面，任何其他內容都*必須*跟隨其后！ -->
<title>用戶資訊管理系統</title>
<!-- 1. 匯入CSS的全域樣式 -->
<link href="https://www.cnblogs.com/guizimo/p/css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery匯入，建議使用1.9以上的版本 -->
<script src="https://www.cnblogs.com/guizimo/p/js/jquery-2.1.0.min.js"></script>
<!-- 3. 匯入bootstrap的js檔案 -->
<script src="https://www.cnblogs.com/guizimo/p/js/bootstrap.min.js"></script>
<style type="text/css">
td, th {
text-align: center;
}
</style>
</head>
<body>
<div >
<h3 style="text-align: center">用戶資訊串列</h3>
<table border="1" >
<tr >
<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>操作</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 href="https://www.cnblogs.com/guizimo/p/update.html">修改</a> <a
href="">洗掉</a></td>
</tr>
</c:forEach>
<tr>
<td colspan="8" align="center"><a href="https://www.cnblogs.com/guizimo/p/add.html">添加聯系人</a></td>
</tr>
</table>
</div>
</body>
</html>
servlet
代碼檔案很多，就不一一展示了
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 {
//呼叫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);
}
}
測驗
登錄
思路
登錄功能首先就是對表單提交的資料進行比對，驗證碼可以在生成的時候就把它存入到session中，然后在servlet中進行比對，其他的欄位在通過呼叫dao層的JDBC操作資料庫進行比對，最后把登錄成功的用戶資訊存入session中
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>管理員登錄</title>
<!-- 1. 匯入CSS的全域樣式 -->
<link href="https://www.cnblogs.com/guizimo/p/css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery匯入，建議使用1.9以上的版本 -->
<script src="https://www.cnblogs.com/guizimo/p/js/jquery-2.1.0.min.js"></script>
<!-- 3. 匯入bootstrap的js檔案 -->
<script src="https://www.cnblogs.com/guizimo/p/js/bootstrap.min.js"></script>
<script type="text/javascript">
function refreshCode() {
let vcode = document.getElementById("vcode");
vcode.src = "https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/checkCodeServlet?=" + new Date().getTime();
}
</script>
</head>
<body>
<div style="width: 400px;">
<h3 style="text-align: center;">管理員登錄</h3>
<form action="${pageContext.request.contextPath}/loginServlet" method="post">
<div >
<label for="user">用戶名：</label>
<input type="text" name="username" id="user" placeholder="請輸入用戶名"/>
</div>
<div >
<label for="password">密碼：</label>
<input type="password" name="password" id="password" placeholder="請輸入密碼"/>
</div>
<div >
<label for="vcode">驗證碼：</label>
<input type="text" name="verifycode" id="verifycode" placeholder="請輸入驗證碼"
style="width: 120px;"/>
<a href="javascript:refreshCode()"><img src="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/checkCodeServlet"
title="看不清點擊重繪" id="vcode"/></a>
</div>
<hr/>
<div style="text-align: center;">
<input type="submit" value="https://www.cnblogs.com/guizimo/p/登錄">
</div>
</form>
<!-- 出錯顯示的資訊框 -->
<div role="alert">
<button type="button" data-dismiss="alert">
<span>×</span></button>
<strong>${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 {
//設定編碼
req.setCharacterEncoding("utf-8");
//傳遞過來的驗證碼
String verifycode = req.getParameter("verifycode");
HttpSession session = req.getSession();
//session里面的驗證碼
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", "登錄失敗");
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快取
response.setHeader("pragma","no-cache");
response.setHeader("cache-control","no-cache");
response.setHeader("expires","0");
//在記憶體中創建一個長80，寬30的圖片，默認黑色背景
//引數一：長
//引數二：寬
//引數三：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();
//設定畫筆顏色為灰色
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);
//設定畫筆顏色為黃色
g.setColor(Color.YELLOW);
//設定字體的小大
g.setFont(new Font("黑體",Font.BOLD,24));
//向圖片上寫入驗證碼
g.drawString(checkCode,15,25);
//將記憶體中的圖片輸出到瀏覽器
//引數一：圖片物件
//引數二：圖片的格式，如PNG,JPG,GIF
//引數三：圖片輸出到哪里去
ImageIO.write(image,"PNG",response.getOutputStream());
}
/**
* 產生4位隨機字串
*/
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字串中獲取下標為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);
}
}
測驗
添加人員
思路
添加操作就是把jsp提交的表單的資料向資料庫里面存盤，程序為jsp->servlet->service->dao
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檔案-->
<!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：網頁可以根據設定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，為1:1 -->
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- 上述3個meta標簽*必須*放在最前面，任何其他內容都*必須*跟隨其后！ -->
<title>添加用戶</title>
<!-- 1. 匯入CSS的全域樣式 -->
<link href="https://www.cnblogs.com/guizimo/p/css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery匯入，建議使用1.9以上的版本 -->
<script src="https://www.cnblogs.com/guizimo/p/js/jquery-2.1.0.min.js"></script>
<!-- 3. 匯入bootstrap的js檔案 -->
<script src="https://www.cnblogs.com/guizimo/p/js/bootstrap.min.js"></script>
</head>
<body>
<div >
<center><h3>添加聯系人頁面</h3></center>
<form action="${pageContext.request.contextPath}/addUserServlet" method="post">
<div >
<label for="name">姓名：</label>
<input type="text" id="name" name="name" placeholder="請輸入姓名">
</div>
<div >
<label>性別：</label>
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/男" checked="checked"/>男
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/女"/>女
</div>
<div >
<label for="age">年齡：</label>
<input type="text" id="age" name="age" placeholder="請輸入年齡">
</div>
<div >
<label for="address">籍貫：</label>
<select name="address" id="jiguan">
<option value="https://www.cnblogs.com/guizimo/p/廣東">廣東</option>
<option value="https://www.cnblogs.com/guizimo/p/廣西">廣西</option>
<option value="https://www.cnblogs.com/guizimo/p/湖南">湖南</option>
</select>
</div>
<div >
<label for="qq">QQ：</label>
<input type="text" name="qq" placeholder="請輸入QQ號碼"/>
</div>
<div >
<label for="email">Email：</label>
<input type="text" name="email" placeholder="請輸入郵箱地址"/>
</div>
<div style="text-align: center">
<input type="submit" value="https://www.cnblogs.com/guizimo/p/提交" />
<input type="reset" value="https://www.cnblogs.com/guizimo/p/重置" />
<input type="button" value="https://www.cnblogs.com/guizimo/p/回傳" />
</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);
}
}
測驗
修改
思路
首先我們需要在打開jsp頁面的時候就查詢到這樣的一條記錄，通過這一條記錄的id作為表單的隱藏域，在servlet里面將資料進行保存即可
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="https://www.cnblogs.com/guizimo/p/css/bootstrap.min.css" rel="stylesheet">
<script src="https://www.cnblogs.com/guizimo/p/js/jquery-2.1.0.min.js"></script>
<script src="https://www.cnblogs.com/guizimo/p/js/bootstrap.min.js"></script>
</head>
<body>
<div style="width: 400px;">
<h3 style="text-align: center;">修改聯系人</h3>
<form action="${pageContext.request.contextPath}/updateUserServlet" method="post">
<!-- 隱藏域 提交id-->
<input type="hidden" name="id" value="https://www.cnblogs.com/guizimo/p/${user.id}">
<div >
<label for="name">姓名：</label>
<input type="text" id="name" name="name" value="https://www.cnblogs.com/guizimo/p/${user.name}" readonly="readonly" placeholder="請輸入姓名" />
</div>
<div >
<label>性別：</label>
<c:if test="${user.gender == '男'}">
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/男" checked />男
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/女" />女
</c:if>
<c:if test="${user.gender == '女'}">
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/男" />男
<input type="radio" name="gender" value="https://www.cnblogs.com/guizimo/p/女" checked />女
</c:if>
</div>
<div >
<label for="age">年齡：</label>
<input type="text" value="https://www.cnblogs.com/guizimo/p/${user.age}" id="age" name="age" placeholder="請輸入年齡" />
</div>
<div >
<label for="address">籍貫：</label>
<select name="address" id="address" >
<c:if test="${user.address == '陜西'}">
<option value="https://www.cnblogs.com/guizimo/p/陜西" selected>陜西</option>
<option value="https://www.cnblogs.com/guizimo/p/北京">北京</option>
<option value="https://www.cnblogs.com/guizimo/p/上海">上海</option>
</c:if>
<c:if test="${user.address == '北京'}">
<option value="https://www.cnblogs.com/guizimo/p/陜西" >陜西</option>
<option value="https://www.cnblogs.com/guizimo/p/北京" selected>北京</option>
<option value="https://www.cnblogs.com/guizimo/p/上海">上海</option>
</c:if>
<c:if test="${user.address == '上海'}">
<option value="https://www.cnblogs.com/guizimo/p/陜西" >陜西</option>
<option value="https://www.cnblogs.com/guizimo/p/北京">北京</option>
<option value="https://www.cnblogs.com/guizimo/p/上海" selected>上海</option>
</c:if>
</select>
</div>
<div >
<label for="qq">QQ：</label>
<input type="text" id="qq" value="https://www.cnblogs.com/guizimo/p/${user.qq}" name="qq" placeholder="請輸入QQ號碼"/>
</div>
<div >
<label for="email">Email：</label>
<input type="text" id="email" value="https://www.cnblogs.com/guizimo/p/${user.email}" name="email" placeholder="請輸入郵箱地址"/>
</div>
<div style="text-align: center">
<input type="submit" value="https://www.cnblogs.com/guizimo/p/提交" />
<input type="reset" value="https://www.cnblogs.com/guizimo/p/重置" />
<a href="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/userListServlet">回傳</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.呼叫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.設定編碼
req.setCharacterEncoding("utf-8");
//2.獲取map
Map<String, String[]> map = req.getParameterMap();
//3.封裝物件
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//4.呼叫Service修改
UserService service = new UserServiceImpl();
service.updateUser(user);
//5.跳轉到查詢所有Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測驗
洗掉
思路
通過獲取到對應的id即可到servlet中處理，操作資料庫洗掉，在進行洗掉的時候可出現提示框
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.呼叫service洗掉
UserService service = new UserServiceImpl();
service.deleteUser(id);
//3.跳轉到查詢所有Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測驗
洗掉選擇的多個
思路
和洗掉差不多，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.獲取所有id
String[] ids = req.getParameterValues("uid");
//2.呼叫service洗掉
UserService service = new UserServiceImpl();
service.delSelectedUser(ids);
//3.跳轉查詢所有Servlet
resp.sendRedirect(req.getContextPath()+"/userListServlet");
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
}
測驗
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，操作資料庫進行查詢
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：網頁可以根據設定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，為1:1 -->
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- 上述3個meta標簽*必須*放在最前面，任何其他內容都*必須*跟隨其后！ -->
<title>用戶資訊管理系統</title>
<!-- 1. 匯入CSS的全域樣式 -->
<link href="https://www.cnblogs.com/guizimo/p/css/bootstrap.min.css" rel="stylesheet">
<!-- 2. jQuery匯入，建議使用1.9以上的版本 -->
<script src="https://www.cnblogs.com/guizimo/p/js/jquery-2.1.0.min.js"></script>
<!-- 3. 匯入bootstrap的js檔案 -->
<script src="https://www.cnblogs.com/guizimo/p/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("您確定要洗掉嗎？")) {
//訪問路徑
location.href = "https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/delUserServlet?id=" + id;
}
}
window.onload = function () {
//給洗掉選中按鈕添加單擊事件
document.getElementById("delSelected").onclick = function () {
if (confirm("您確定要洗掉選中條目嗎？")) {
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.獲取下邊串列中所有的cb
var cbs = document.getElementsByName("uid");
//3.遍歷
for (var i = 0; i < cbs.length; i++) {
//4.設定這些cbs[i]的checked狀態 = firstCb.checked
cbs[i].checked = this.checked;
}
}
}
</script>
</head>
<body>
<div >
<h3 style="text-align: center">用戶資訊串列</h3>
<div style="float: left;">
<form action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
<div >
<label for="exampleInputName2">姓名</label>
<input type="text" name="name" value="https://www.cnblogs.com/guizimo/p/${condition.name[0]}" id="exampleInputName2">
</div>
<div >
<label for="exampleInputName3">籍貫</label>
<input type="text" name="address" value="https://www.cnblogs.com/guizimo/p/${condition.address[0]}"
id="exampleInputName3">
</div>
<div >
<label for="exampleInputEmail2">郵箱</label>
<input type="text" name="email" value="https://www.cnblogs.com/guizimo/p/${condition.email[0]}"
id="exampleInputEmail2">
</div>
<button type="submit" >查詢</button>
</form>
</div>
<div style="float: right;margin: 5px;">
<a href="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/add.jsp">添加聯系人</a>
<a href="javascript:void(0);" id="delSelected">洗掉選中</a>
</div>
<form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
<table border="1" >
<tr >
<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>操作</th>
</tr>
<c:forEach items="${pb.list}" var="user" varStatus="s">
<tr>
<td><input type="checkbox" name="uid" value="https://www.cnblogs.com/guizimo/p/${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>${user.email}</td>
<td>
<a
href="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a>
<a href="javascript:deleteUser(${user.id});">洗掉</a>
</td>
</tr>
</c:forEach>
</table>
</form>
<div>
<nav aria-label="Page navigation">
<ul >
<c:if test="${pb.currentPage == 1}">
<li >
<a href="https://www.cnblogs.com/guizimo/p/${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="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${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="${pb.currentPage == i}">
<li ><a
href="https://www.cnblogs.com/guizimo/p/${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="https://www.cnblogs.com/guizimo/p/${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${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="${pb.currentPage == pb.totalPage}">
<li >
<a href="https://www.cnblogs.com/guizimo/p/${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="${pb.currentPage != pb.totalPage}">
<li>
<a href="https://www.cnblogs.com/guizimo/p/${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.獲取引數
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";
}
//獲取條件查詢引數
Map<String, String[]> condition = request.getParameterMap();
//2.呼叫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);
}
}
測驗
條件查詢
思路
主要是在sql陳述句的撰寫
jsp
<div style="float: left;">
<form action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
<div >
<label for="exampleInputName2">姓名</label>
<input type="text" name="name" value="https://www.cnblogs.com/guizimo/p/${condition.name[0]}" id="exampleInputName2">
</div>
<div >
<label for="exampleInputName3">籍貫</label>
<input type="text" name="address" value="https://www.cnblogs.com/guizimo/p/${condition.address[0]}"
id="exampleInputName3">
</div>
<div >
<label for="exampleInputEmail2">郵箱</label>
<input type="text" name="email" value="https://www.cnblogs.com/guizimo/p/${condition.email[0]}"
id="exampleInputEmail2">
</div>
<button type="submit" >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();
//定義引數的集合
List<Object> params = new ArrayList<Object>();
for (String key : keySet) {
//排除分頁條件引數
if("currentPage".equals(key) || "rows".equals(key)){
continue;
}
//獲取value
String value = https://www.cnblogs.com/guizimo/p/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();
//定義引數的集合
List<Object> params = new ArrayList<Object>();
for (String key : keySet) {
//排除分頁條件引數
if("currentPage".equals(key) || "rows".equals(key)){
continue;
}
//獲取value
String value = https://www.cnblogs.com/guizimo/p/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 ?,? ");
//添加分頁查詢引數值
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());
}
測驗
感謝
黑馬程式員
萬能的網路
以及勤勞的自己
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