JavaWeb实现学生管理系统

你的名字 2023-09-26 11:48 47阅读 0赞

#### JavaWeb实现学生管理系统 ####

*  一、项目介绍
 *  二、项目结构
 *  三、前期准备
 *   *  1.配置maven环境，在pom.xml配置文件中配置项目所依赖的jar包
     *  2.在MySql数据库中，创建登录注册表login和学生信息表student
     *   *  （1）登录注册表login
         *  （2）学生信息表student
         *  （3）创建数据表代码
     *  3.配置tocamt
 *  四、代码实现
 *   *  1.JSP界面实现
     *   *  （1）首页-登录界面 (index.jsp)
         *  （2）用户注册界面 (register.jsp)
         *  （3）登录成功-主界面 (main.jsp)
         *  （4）添加学生界面 (addStudent.jsp)
         *  （5）分页查询界面（showAllStudentByPageNo.jsp)
         *  （6）查看所有学生信息界面
         *  （7） 修改学生界面 (updateStudent.jsp)
     *  2.JavaBean实体类封装数据
     *   *  （1）学生信息类 (Student.java)
         *  （2）分页帮助类 (Page.java)
         *  （3）JDBC工具类 (DBTools.java)
     *  3.三层架构
     *   *  （1）表示层servlet
         *   *  ① 用户登录表示层 (LoginServlet.java)
             *  ② 用户注册表示层 (RegisterServlet.java)
             *  ③ 分页查询表示层 (ShowStudentsByPageServlet.java)
             *  ④ 查询所学生信息表示层 (ShowAllStudentsServlet.java)
             *  ⑤ 添加学生表示层 (AddServlet.java)
             *  ⑥ 删除学生表示层 (DeleteServlet.java)
             *  ⑦ 根据学号查询学生信息表示层 (QueryStudentBySnoSevlet.java)
             *  ⑧ 修改学生信息表示层 (UpdateServlet.java)
             *  ⑨ 退出登录表示层 (QuitServlet.java)
         *  （2）业务逻辑层service
         *   *  ① Service接口（StudentService.java）
             *  ② 接口的实现类（StudentServiceImpl.java）
         *  （3）数据访问层dao
         *   *  ① 接口（StudentDao.java）
             *  ② 接口的实现类（StudentDaoImpl.java）

## 一、项目介绍 ##

*该项目是基于JavaWeb实现的学生管理系统，使用maven进行管理jar包，能够对学生信息进行增删改查，分页查询，以及实现管理员的注册、登录*  
*数据库：MySQL*  
*开发工具：idea*  
*开发环境：jdk 1.8 + tomcat*

## 二、项目结构 ##

![在这里插入图片描述][8848519781294cc498bcfbdba562c477.png]![在这里插入图片描述][78591850716e4e509025f968dec836ea.png]

## 三、前期准备 ##

### 1.配置maven环境，在pom.xml配置文件中配置项目所依赖的jar包 ###

<dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <version>8.0.21</version>
        </dependency>
    
        <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>javax.servlet-api</artifactId>
          <version>3.0.1</version>
          <scope>provided</scope>
        </dependency>
    
        <dependency>
          <groupId>javax.servlet.jsp</groupId>
          <artifactId>jsp-api</artifactId>
          <version>2.2</version>
          <scope>provided</scope>
        </dependency>

### 2.在MySql数据库中，创建登录注册表login和学生信息表student ###

#### （1）登录注册表login ####

![在这里插入图片描述][cda14db706974d28b716c44de46d8a7b.png_pic_center]

#### （2）学生信息表student ####

![在这里插入图片描述][a2b0102f5de1459b855708229a70b6ca.png]

#### （3）创建数据表代码 ####

SET NAMES utf-8;
    CREATE DATABASE studentManager;
    USE studentManager;
    CREATE TABLE student
    (
      sno INT PRIMARY KEY,
      sname VARCHAR(20) NOT NULL,
      sex CHAR(4) ,
      age INT DEFAULT 20,
      phone VARCHAR(30) 
    );
    
    INSERT INTO student VALUES(1001,'jack','男',23,'13389076524');
    INSERT INTO student VALUES(1002,'rose','女',23,'18760987543');
    INSERT INTO student VALUES(1003,'tom','男',23,'13389067823');
    INSERT INTO student VALUES(1004,'王麻子','男',23,'13560738947');
    INSERT INTO student VALUES(1005,'大麻子','男',23,'18899067532');
    
    INSERT INTO student VALUES(1006,'小麻子','男',23,'15678634789');
    INSERT INTO student VALUES(1007,'老麻子','男',23,'12199834572');
    INSERT INTO student VALUES(1008,'张三','男',23,'15533098843');
    INSERT INTO student VALUES(1009,'长萨珊','女',23,'12209835679');
    INSERT INTO student VALUES(1010,'李四','女',23,'15509087635');
    
    INSERT INTO student VALUES(1011,'王五','男',23,'15788679043');
    INSERT INTO student VALUES(1012,'赵六','女',23,'12489034506');
    INSERT INTO student VALUES(1013,'刘二','男',23,'13560596743');
    
    CREATE TABLE login
    (
      uid INT PRIMARY KEY,
      pwd VARCHAR(20) NOT NULL,
    );
    
    INSERT INTO login VALUES(1, '1234');
    INSERT INTO login VALUES(2, '2222');
    INSERT INTO login VALUES(3, '6688');

### 3.配置tocamt ###

![在这里插入图片描述][6a22f18495194df2989882a813dd7933.png]![在这里插入图片描述][3c848d3c1e63473a922d17ec945215d5.png]

## 四、代码实现 ##

### 1.JSP界面实现 ###

#### （1）首页-登录界面 (index.jsp) ####

<%@ page language="java" contentType="text/html; charset=utf-8"  pageEncoding="utf-8"%>
    <!DOCTYPE html>
    <html>
    <head>
        <title>学生信息管理平台</title>
        <style>
    
            .titleDiv{
          
                height: 85px;
                color:white;
                padding-top: 30px;
                font-size: 50px;
                padding-left: 30px;
                font-family: 隶书;
            }
    
            .mainDiv{
          
                width: 899px;
                height: 500px;
                border: 4px rgb(237, 237, 237) solid;
                border-radius: 5px;
                background-image: url("输入你要的图片链接！");
                margin: auto;
                margin-top: 50px;
            }
    
            .loginDiv{
          
                height: 220px;
                width: 260px;
                padding:50px;
                background-color:rgba(255,255,255,0.9);
                border-radius:25px;
                border:1px #bdbdbd solid;
                opacity:0.9;
                float: right;
                margin-right: 100px
            }
    
            .name{
          
                font-size: 25px;
            }
    
            a{
          
                font-size:15px;
                color:#59c2c5;
                padding-left:20px;
            }
    
            .item{
          
                height:60px;
            }
    
            .item input{
          
                line-height:40px;
                width:245px;
                border:none;
                border-bottom: 1px solid #59c2c5;
                margin-bottom: 20px;
                margin-top: 10px;
            }
    
            .login-btn{
          
                display:block;
                width:255px;
                height:50px;
                color:#fff;
                background:#59c2c5;
                font-size:16px;
                line-height:30px;
                text-align:center;
                border-radius:10px;
                border:none;
                margin-bottom: 20px;
                margin-top: 10px;
            }
        </style>
    
    
    
    </head>
    
    <body>
    
    <div class="mainDiv">
        <div class="titleDiv">学生信息管理平台</div>
    
        <form action="LoginServlet" method="post">
        <div class="loginDiv">
            <div class="name">
                用户登录 <a href="register.jsp"> 立即注册</a>
            </div>
    
            <div class=item>
                <input type="text" name="uid" placeholder="用户名"/>
            </div>
            <div class=item>
                <input type="password" name="pwd" placeholder="密码"/>
            </div>
            <input type="submit" class="login-btn" value="登 录"/>
            <%
                if(session.getAttribute("loginErrorMessage") != null){
    
                    String loginErrorMessage = (String)session.getAttribute("loginErrorMessage");
                    out.print(loginErrorMessage);
                }
            %>
            <%
                String register = (String) request.getAttribute("register");
                if (register!= null) {
                    if (register.equals("reg")) {
                        out.println("注册成功, 请登录！");
                    }
                }
            %>
        </div>
        </form>
    </div>
    </body>
    </html>

#### （2）用户注册界面 (register.jsp) ####

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
    <!DOCTYPE html>
    <html>
    <head>
        <title>注册账号</title>
    
        <style>
            .mainDiv{
          
                width: 899px;
                height: 500px;
                border: 4px rgb(237, 237, 237) solid;
                border-radius: 5px;
                background-image: url("输入你要的图片链接！");
                margin: auto;
                margin-top: 50px;
            }
    
    
            .titleDiv{
          
                height: 85px;
                color:white;
                padding-top: 30px;
                font-size: 50px;
                padding-left: 30px;
                font-family: 隶书;
            }
    
            .registerDiv{
          
                height: 220px;
                width: 260px;
                padding:50px;
                background-color:rgba(255,255,255,0.9);
                border-radius:25px;
                border:1px #bdbdbd solid;
                opacity:0.9;
                float: right;
                margin-right: 100px
            }
    
            .name{
          
                font-size: 25px;
            }
    
            .item{
          
                height:60px;
            }
    
            .item input{
          
                line-height:40px;
                width:245px;
                border:none;
                border-bottom: 1px solid #59c2c5;
                margin-bottom: 20px;
                margin-top: 10px;
            }
    
            .btn{
          
                display:block;
                width:255px;
                height:50px;
                color:#fff;
                background:#59c2c5;
                font-size:16px;
                line-height:30px;
                text-align:center;
                border-radius:10px;
                border:none;
                margin-top: 10px;
            }
    
            a{
          
                font-size:18px;
                padding-left:200px;
                padding-bottom: 50px;
                color:#59c2c5;
    
            }
    
    
        </style>
    </head>
    
    </head>
    <body>
    <div class="mainDiv">
        <div class="titleDiv">学生信息管理平台</div>
        <form action = "RegisterServlet">
            <div class = "registerDiv">
                <div class = "name">用户注册</div>
                <div class = "item">
                    <input type = "text" name = "uid" placeholder="账号"/>
                </div>
                <div class = "item">
                    <input type = "password" name = "pwd"  placeholder="密码"/>
                </div>
                <input type = "submit" class = "btn" value = "注册"/>
                <a href = "index.jsp" >返回</a>
    
            </div>
        </form>
    </div>
    </body>
    </html>

#### （3）登录成功-主界面 (main.jsp) ####

<%@ page language="java" contentType="text/html; charset=utf-8"  pageEncoding="utf-8"%>
    <%@ page import="com.stu.po.Student" %>
    <!DOCTYPE html>
    <html >
    <head>
        <title>学生信息管理平台</title>
    
        <style>
            .titleDiv{
          
                height: 85px;
                color:white;
                padding-top: 30px;
                font-size: 50px;
                padding-left: 30px;
                font-family: 隶书;
            }
    
            .mainDiv{
          
                width: 899px;
                height: 500px;
                border: 4px rgb(237, 237, 237) solid;
                border-radius: 5px;
                background-image: url("https://img1.baidu.com/it/u=4271373647,1745018175&fm=253&fmt=auto&app=138&f=JPEG?w=889&h=500");
                margin: auto;
                margin-top: 50px;
                background-size: auto;
            }
    
            .Navigation{
          
                width: 899px;
                height: 200px;
                background-color:#59c2c5;
                opacity:0.8;
                text-align: center;
                line-height: 200px;
                font-family: 楷体;
    
            }
    
            a{
          
                font-size:30px;
                color:whitesmoke;
                padding-left:20px;
                text-decoration: none;
            }
    
            a:hover{
          
                color: blue;
                font-family: 隶书;
            }
    
        </style>
    </head>
    <body>
    <div class="mainDiv">
        <div class="titleDiv">欢迎进入学生信息管理平台</div>
        <%
            if(session.getAttribute("login") == null) {
                session.setAttribute("loginErrorMessage", "您必须先登录才能访问主页！");
                response.sendRedirect("index.jsp");
            }
        %>
        <div class="Navigation">
            <a href="addStudent.jsp">添加学生</a>
            <a href="ShowStudentsByPageServlet">分页查询</a>
            <a href="ShowAllStudentsServlet">查看所有学生信息</a>
            <a href="QuitServlet">退出登录</a>
        </div>
    </div>
    </body>
    </html>

#### （4）添加学生界面 (addStudent.jsp) ####

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <!DOCTYPE html>
    <html>
    <head>
        <title>添加学生信息</title>
    
        <style>
            .titleDiv{
          
                height: 2px;
                color:white;
                padding-top: 12px;
                font-size: 50px;
                padding-left: 30px;
                font-family: 隶书;
            }
    
            .mainDiv{
          
                width: 899px;
                height: 500px;
                border: 4px rgb(237, 237, 237) solid;
                border-radius: 5px;
                background-image: url("图片链接");
                margin: auto;
                margin-top: 50px;
                background-size: auto;
            }
    
            .addDiv{
          
                height: 380px;
                width: 260px;
                padding:50px;
                background-color:rgba(255,255,255,0.9);
                border-radius:25px;
                border:1px #bdbdbd solid;
                opacity:0.9;
                float: right;
                margin-right: 80px
            }
    
            .name{
          
                font-size: 20px;
    
            }
    
            .item{
          
                height:60px;
            }
    
            .item input{
          
                line-height:40px;
                width:245px;
                border:none;
                border-bottom: 1px solid #59c2c5;
                margin-bottom: 20px;
                margin-top: 10px;
            }
    
            .btn{
          
                display:block;
                width:255px;
                height:50px;
                color:#fff;
                background:#59c2c5;
                font-size:16px;
                line-height:30px;
                text-align:center;
                border-radius:10px;
                border:none;
                margin-top: 10px;
            }
    
            a{
          
                font-size:18px;
                padding-left:200px;
                padding-bottom: 50px;
                color:#59c2c5;
    
            }
    
        </style>
    </head>
    
    <body>
    <div class="mainDiv">
        <div class="titleDiv">学生信息管理平台</div>
        <form action = "AddServlet">
            <div class = "addDiv">
                <div class = "name">添加学生信息</div>
    
                <div class = "item">
                    <input type = "text" name="sno" placeholder="学号"/>
                </div>
                <div class = "item">
                    <input type = "text" name="sname" placeholder="姓名"/>
                </div>
                <div class = "item">
                    <input type = "text" name="sex" placeholder="性别"/>
                </div>
                <div class = "item">
                    <input type = "text" name="age" placeholder="年龄"/>
                </div>
                <div class = "item">
                    <input type = "text" name="phone" placeholder="电话"/>
                </div>
                <input type = "submit" class = "btn" value = "添加"/>
                <a href = "main.jsp">返回</a>
            </div>
        </form>
    </div>
    </div>
    </body>
    </html>

#### （5）分页查询界面（showAllStudentByPageNo.jsp) ####

<%@ page import="com.stu.po.Student" %>
    <%@ page import="java.util.List" %>
    <%@ page import="com.stu.po.Page" %>
    <%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
    <!DOCTYPE html>
    <html>
    <head>
    
      <title>学生信息管理平台</title>
    
      <style>
        .mainDiv{
          
          width: 900px;
          height: 550px;
          border: 4px rgb(237, 237, 237) solid;
          border-radius: 5px;
          background-image: url("图片链接");
          margin: auto;
          background-size: auto;
        }
    
        .titleDiv{
          
          height: 20px;
          color:white;
          padding-top: 30px;
          font-size: 50px;
          padding-left: 30px;
          font-family: 隶书;
        }
    
        .showStudentDiv{
          
          background-size: cover;
          width:700px;
          height:500px;
          margin: auto;
          margin-top: 50px;
    
        }
    
        .item{
          
          height:40px;
          border-radius:15px;
        }
    
        .item a{
          
          background-color: lightgrey;
          text-decoration: none;
          font-size:15px;
          color:black;
          border-radius:3px;
        }
    
        .item input{
          
          width: 20px;
          text-align: center;
        }
    
    
        table{
          
          width:100%;
          border-collapse:collapse;
          background-color: rgba(255,255,255,0.9);
          opacity: 0.8;
        }
    
    
        table body{
          
          display: block;
          height:300px;
          overflow-y: scroll;
        }
        table td{
          
          border:1px solid #A6A6A6;
          height:30px;
          width: 300px;
          text-align: center;
          font-size: 15px;
        }
        table th{
          
          height:30px;
          border:1px solid #A6A6A6;
        }
    
      </style>
    </head>
    <body>
    <div class="mainDiv">
      <div class="titleDiv">分页查询学生信息</div>
        <div class = "showStudentDiv">
          <table  border="2" cellspacing="0">
            <tr>
              <th><h3>学号</h3></th>
              <th><h3>姓名</h3></th>
              <th><h3>性别</h3></th>
              <th><h3>年龄</h3></th>
              <th><h3>电话</h3></th>
    
            </tr>
            <%
              Page page1 = (Page)request.getAttribute("page1");
    
              for(Student student:page1.getStudent()){
    
            %>
                <tr>
                  <td><%=student.getSno() %></td>
                  <td><%=student.getSname() %></td>
                  <td><%=student.getSex() %></td>
                  <td><%=student.getAge() %></td>
                  <td><%=student.getPhone() %></td>
                </tr>
              <%
                }
              %>
          </table>
    
          <%
            if(page1.getCurrentPage()==page1.getTotalPage()){
          %>
            <div class = item>
              <a href = "ShowStudentsByPageServlet?currentPage=0">首页</a>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getCurrentPage()-1%>">上一页</a>
              <input type = "text" name = "currentPage" value="<%=page1.getTotalPage()+1%>"/>
            </div>
          <%
          } else if(page1.getCurrentPage()==0){
          %>
            <div class = item>
              <input type = "text" name = "currentPage" value="1"/>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getCurrentPage()+1%>">下一页</a>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getTotalPage()%>">尾页</a>
            </div>
          <%
          } else{
          %>
            <div class = item>
              <a href = "ShowStudentsByPageServlet?currentPage=0">首页</a>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getCurrentPage()-1%>">上一页</a>
              <input type = "text" name = "currentPage" value="<%=page1.getCurrentPage()+1%>"/>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getCurrentPage()+1%>">下一页</a>
              <a href = "ShowStudentsByPageServlet?currentPage=<%=page1.getTotalPage()%>">尾页</a>
            </div>
          <%
            }
          %>
    
          <a href = "main.jsp">返回</a>
        </div>
    </div>
    </body>
    </html>

#### （6）查看所有学生信息界面 ####

<%@ page language="java" contentType="text/html; charset=utf-8"  pageEncoding="utf-8"%>
    <%@ page import="com.stu.po.Student" %>
    <%@ page import="java.util.List" %>
    <!DOCTYPE html>
    <html>
    <head>
    	<title>学生信息管理平台</title>
    
    	<style>
    		.mainDiv{
          
    			width: 900px;
    			height: 700px;
    			border: 4px rgb(237, 237, 237) solid;
    			border-radius: 5px;
    			background-image: url("图片链接");
    			margin: auto;
    			background-size: auto;
    		}
    
    		.titleDiv{
          
    			height: 20px;
    			color:white;
    			padding-top: 30px;
    			font-size: 50px;
    			padding-left: 30px;
    			font-family: 隶书;
    		}
    
    		.showStudentDiv{
          
    			background-size: cover;
    			width:700px;
    			height:500px;
    			margin: auto;
    			margin-top: 50px;
    
    		}
    
    		.item{
          
    			height:40px;
    			border-radius:15px;
    		}
    
    		.item a{
          
    			background-color: lightgrey;
    			text-decoration: none;
    			font-size:15px;
    			color:black;
    			border-radius:3px;
    		}
    
    
    		table{
          
    			width:100%;
    			border-collapse:collapse;
    			background-color: rgba(255,255,255,0.9);
    			opacity: 0.8;
    		}
    
    
    		table body{
          
    			display: block;
    			height:300px;
    			overflow-y: scroll;
    		}
    		table td{
          
    			border:1px solid #A6A6A6;
    			height:30px;
    			width: 300px;
    			text-align: center;
    			font-size: 15px;
    		}
    		table th{
          
    			height:30px;
    			border:1px solid #A6A6A6;
    		}
    
    
    
    	</style>
    </head>
    <body>
    <div class="mainDiv">
    	<div class="titleDiv">查看所有学生信息</div>
    	<div class = "showStudentDiv">
    		<table  border="2" cellspacing="0">
    			<tr>
    				<th><h3>学号</h3></th>
    				<th><h3>姓名</h3></th>
    				<th><h3>性别</h3></th>
    				<th><h3>年龄</h3></th>
    				<th><h3>电话</h3></th>
    				<th><h3>操作</h3></th>
    			</tr>
    			<%
    
    				List<Student> allStudents = (List<Student>)session.getAttribute("allStudents");
    				for (int i = 0; i < allStudents.size(); i++) {
    					Student s  = allStudents.get(i);
    			%>
    			<tr>
    				<td><%=s.getSno() %></td>
    				<td><%=s.getSname() %></td>
    				<td><%=s.getSex() %></td>
    				<td><%=s.getAge() %></td>
    				<td><%=s.getPhone() %></td>
    				<td>
    					<a href = "DeleteServlet?sno=<%=s.getSno() %>">删除</a>
    					<a href = "QueryStudentBySnoServlet?sno=<%=s.getSno()%>">修改</a>
    				</td>
    			</tr>
    			<%
    				}
    			%>
    		</table>
    		<a href = "main.jsp">返回</a>
    	</div>
    
    </div>
    </body>
    </html>

#### （7） 修改学生界面 (updateStudent.jsp) ####

<%@ page language="java" contentType="text/html; charset=utf-8"  pageEncoding="utf-8"%>
    <%@ page import="com.stu.po.Student" %>
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>修改学生信息</title>
    
        <style>
            .titleDiv{
          
                height: 20px;
                color:white;
                padding-top: 30px;
                font-size: 50px;
                padding-left: 30px;
                font-family: 隶书;
            }
    
            .mainDiv{
          
                width: 899px;
                height: 500px;
                border: 4px rgb(237, 237, 237) solid;
                border-radius: 5px;
                background-image: url("https://img1.baidu.com/it/u=4271373647,1745018175&fm=253&fmt=auto&app=138&f=JPEG?w=889&h=500");
                margin: auto;
                margin-top: 50px;
                background-size: auto;
            }
    
            .updateDiv{
          
                height: 340px;
                width: 260px;
                padding:50px;
                background-color:rgba(255,255,255,0.9);
                border-radius:25px;
                border:1px #bdbdbd solid;
                opacity:0.9;
                float: right;
                margin-right: 100px
            }
    
            .name{
          
                font-size: 25px;
            }
    
            .item{
          
                height:60px;
            }
    
            .item input{
          
                line-height:40px;
                width:245px;
                border:none;
                border-bottom: 1px solid #59c2c5;
                margin-bottom: 20px;
                margin-top: 10px;
            }
    
            .btn{
          
                display:block;
                width:255px;
                height:50px;
                color:#fff;
                background:#59c2c5;
                font-size:16px;
                line-height:30px;
                text-align:center;
                border-radius:10px;
                border:none;
                margin-top: 10px;
            }
    
            a{
          
                font-size:18px;
                padding-right:100px;
                padding-bottom: 50px;
            }
    
        </style>
    </head>
    
    <body>
    <div class="mainDiv">
        <div class="titleDiv">学生信息管理平台</div>
    
        <form action = "UpdateServlet">
            <%
                Student s =(Student)request.getAttribute("student");
            %>
            <div class = "updateDiv">
                <div class = "name">修改学生信息</div>
                <input type="hidden" name="sno" value="<%=s.getSno()%>"/>
                <div class = "item">
                    <input type = "text" name="sname" placeholder="姓名" value="<%=s.getSname()%>"/>
                </div>
                <div class = "item">
                    <input type = "text" name="sex" placeholder="性别" value="<%=s.getSex()%>"/>
                </div>
                <div class = "item">
                    <input type = "text" name="age" placeholder="年龄" value="<%=s.getAge()%>"/>
                </div>
                <div class = "item">
                    <input type = "text" name="phone" placeholder="电话" value="<%=s.getPhone()%>"/>
                </div>
                <input type = "submit" class = "btn" value = "修改"/>
                <a href = "showAllStudents.jsp">返回</a>
            </div>
        </form>
    </div>
    </div>
    </body>
    </html>

### 2.JavaBean实体类封装数据 ###

#### （1）学生信息类 (Student.java) ####

package com.stu.po;
    
    public class Student {
        
        //这是一个实体类，javabean
    
        private int sno;
        private String sname;
        private String sex;
        private int age;
        private String phone;
    
        public Student(int sno, String sname, String sex, int age, String phone) {
        
            this.sno = sno;
            this.sname = sname;
            this.sex = sex;
            this.age = age;
            this.phone = phone;
        }
    
        public Student() {
        
    
        }
    
        public int getSno() {
        
            return sno;
        }
    
        public void setSno(int sno) {
        
            this.sno = sno;
        }
    
        public String getSname() {
        
            return sname;
        }
    
        public void setSname(String sname) {
        
            this.sname = sname;
        }
    
        public String getSex() {
        
            return sex;
        }
    
        public void setSex(String sex) {
        
            this.sex = sex;
        }
    
        public int getAge() {
        
            return age;
        }
    
        public void setAge(int age) {
        
            this.age = age;
        }
    
        public String getPhone() {
        
            return phone;
        }
    
        public void setPhone(String phone) {
        
            this.phone = phone;
        }
    }

#### （2）分页帮助类 (Page.java) ####

package com.stu.po;
    
    import java.util.List;
    
    //分页帮助类
    public class Page {
        
        private int currentPage;  //当前页面
        private int pageSize;     //一页有多少条数据
        private int totalCount;   //一共有多少条数据
        private int totalPage;    //一共有多少页
        private List<Student> student;
        public Page() {
        
    
        }
        public Page(int currentPage, int pageSize, int totalCount, int totalPage, List<Student> student) {
        
            this.currentPage = currentPage;
            this.pageSize = pageSize;
            this.totalCount = totalCount;
            this.totalPage = totalPage;
            this.student = student;
        }
    
        public int getCurrentPage() {
        
            return currentPage;
        }
    
        public void setCurrentPage(int currentPage) {
        
            this.currentPage = currentPage;
        }
    
        public int getPageSize() {
        
            return pageSize;
        }
    
        public void setPageSize(int pageSize) {
        
            this.pageSize = pageSize;
        }
    
        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<Student> getStudent() {
        
            return student;
        }
    
        public void setStudent(List<Student> student) {
        
            this.student = student;
        }
    }

#### （3）JDBC工具类 (DBTools.java) ####

package com.stu.utils;
    
    public interface DBTools {
        
        public static final String DRIVER_CLASS = "com.mysql.jdbc.Driver";
        public static final String CONN_STR = "jdbc:mysql://localhost:3306/studentmanager?userSSL=false&serverTimezone=Asia/Shanghai";
        public static final String USRENAME = "root";
        public static final String PWD = "123456";
    
    }

### 3.三层架构 ###

#### （1）表示层servlet ####

##### ① 用户登录表示层 (LoginServlet.java) #####

package com.stu.servlet;
    import java.io.IOException;
    
    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 com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    @WebServlet("/LoginServlet")
    public class LoginServlet extends HttpServlet{
        
    
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            this.doPost(req, resp);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
    
            StudentService service = new StudentServiceImpl();
            HttpSession session = request.getSession();
    
            if (session.getAttribute("loginErrorMessage") != null) {
        
                session.invalidate();
            }
            String uid = request.getParameter("uid");
            String pwd = request.getParameter("pwd");
    
    
            int _uid = Integer.parseInt(uid);
            boolean result = service.login(_uid, pwd);
    
            if(result){
        
                session.setAttribute("login", "log");
                response.sendRedirect("main.jsp");
            }else{
        
                response.sendRedirect("index.jsp");
            }
    
        }
    
    }

##### ② 用户注册表示层 (RegisterServlet.java) #####

package com.stu.servlet;
    
    import java.io.IOException;
    
    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 com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    @WebServlet("/RegisterServlet")
    public class RegisterServlet extends HttpServlet{
        
    
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            this.doPost(req, resp);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
    
            StudentService service = new StudentServiceImpl();
            String uid = request.getParameter("uid");
            String pwd = request.getParameter("pwd");
            int _uid = Integer.parseInt(uid);
            boolean result = service.addLogin(_uid,pwd);
    
            if(!result) {
        
                request.setAttribute("register", "reg");
                request.getRequestDispatcher("index.jsp").forward(request, response);
            }else {
        
                request.getRequestDispatcher("register.jsp").forward(request, response);
            }
    
        }
    
    }

##### ③ 分页查询表示层 (ShowStudentsByPageServlet.java) #####

package com.stu.servlet;
    
    import java.io.IOException;
    import java.util.List;
    
    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 com.stu.po.Page;
    import com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    @WebServlet("/ShowStudentsByPageServlet")
    public class ShowStudentsByPageServlet extends HttpServlet{
        
    
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            StudentService Service = new StudentServiceImpl();
            int count = Service.getTotalCount();
    
            Page page = new Page();
    
    
            String currentPage = request.getParameter("currentPage");
    
            if(currentPage == null) {
        
                currentPage = "0";
            }
            int _currentPage = Integer.parseInt(currentPage);
            page.setCurrentPage(_currentPage);
    
            int totalCount = Service.getTotalCount();
            page.setTotalCount(totalCount);
    
    
            int pageSize = 5;
            int totalPage = (totalCount / pageSize) + 1;
            page.setTotalPage(totalPage+1);
    
    
            page.setPageSize(pageSize);
    
            List<Student> student = Service.queryStudentsByPageNo(_currentPage, pageSize);
            page.setStudent(student);
    
            request.setAttribute("page1", page);
            request.getRequestDispatcher("showAllStudentsByPageNo.jsp").forward(request, response);
        }
    
    }

##### ④ 查询所学生信息表示层 (ShowAllStudentsServlet.java) #####

##### ⑤ 添加学生表示层 (AddServlet.java) #####

package com.stu.servlet;
    
    import com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    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;
    
    @WebServlet("/AddServlet")
    public class AddServlet extends HttpServlet{
        
    
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
            this.doPost(req, resp);
        }
    
        @Override
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
    
            StudentService service = new StudentServiceImpl();
            String sno  = request.getParameter("sno");
            String sname  = request.getParameter("sname");
            String sex  = request.getParameter("sex");
            String age  = request.getParameter("age");
            String phone  = request.getParameter("phone");
    
            int _sno = 0;
            if(sno != null || "".equals(sno)){
        
                _sno = Integer.parseInt(sno);
            }
    
            int _age = 0;
            if (age !=null || "".equals(age)){
        
                _age = Integer.parseInt(age);
            }
    
            Student s = new Student(_sno, sname, sex, _age, phone);
            int result = service.addStudent(s);
    
            HttpSession session = request.getSession();
            session.setAttribute("student", "stu");
            response.sendRedirect("main.jsp");
    
        }
    }

##### ⑥ 删除学生表示层 (DeleteServlet.java) #####

##### ⑦ 根据学号查询学生信息表示层 (QueryStudentBySnoSevlet.java) #####

package com.stu.servlet;
    
    import com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    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("/QueryStudentBySnoServlet")
    public class QueryStudentBySnoServlet extends HttpServlet {
        
    
        @Override
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
            //获取sno;
            String sno = request.getParameter("sno");
            int _sno = 0;
            if(sno != null && !"".equals(sno)){
        
                _sno = Integer.parseInt(sno);
            }
    
            //2.查询学生数据
            StudentService service = new StudentServiceImpl();
            Student student = service.queryStudentBySno(_sno);
    
            //3.显示数据
            //存数据
            request.setAttribute("student", student);
            //跳转
            request.getRequestDispatcher("updateStudent.jsp").forward(request,response);
    
        }
    }

##### ⑧ 修改学生信息表示层 (UpdateServlet.java) #####

package com.stu.servlet;
    
    import com.stu.po.Student;
    import com.stu.service.StudentService;
    import com.stu.service.StudentServiceImpl;
    
    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.util.List;
    
    @WebServlet("/UpdateServlet")
    public class UpdateServlet extends HttpServlet {
        
    
        protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {
        
    
            String sno = request .getParameter("sno");
            String sname  = request.getParameter("sname");
            String sex  = request.getParameter("sex");
            String age  = request.getParameter("age");
            String phone  = request.getParameter("phone");
    
            int _sno = 0;
            if(sno != null && !"".equals(sno)){
        
                _sno = Integer.parseInt(sno);
            }
            int _age = 0;
            if(age != null && !"".equals(age)){
        
                _age = Integer.parseInt(age);
            }
    
    
            Student stu = new Student(_sno, sname, sex, _age, phone);
    
            StudentService service = new StudentServiceImpl();
            service.updateStudentBySno(_sno,stu);
    
            //3.跳转界面
            request.getRequestDispatcher("ShowAllStudentsServlet").forward(request, resp);
    
        }
    }

##### ⑨ 退出登录表示层 (QuitServlet.java) #####

#### （2）业务逻辑层service ####

##### ① Service接口（StudentService.java） #####

package com.stu.service;
    
    import java.util.List;
    
    import com.stu.po.Student;
    
    public interface StudentService {
        
    
        //service表示业务逻辑层,定义的每一个方法实际上对应的就是用户的一个需求(请求)
    
        public boolean login(int uid,String pwd);
    
        public boolean addLogin(int uid, String pwd);
    
        public List<Student> getAllStudents();
    
        public List<Student> queryStudentsByPageNo(int current, int pageSize);
    
        public Student deleteStudent(int sno);
    
        public Student queryStudentBySno(int sno);
    
        public int updateStudentBySno(int sno, Student stu) ;
    
        public int getTotalCount();
    
        public int addStudent(Student student);
        
    }

##### ② 接口的实现类（StudentServiceImpl.java） #####

package com.stu.service;
    
    import java.util.List;
    import com.stu.dao.StudentDao;
    import com.stu.dao.StudentDaoImpl;
    import com.stu.po.Student;
    
    public class StudentServiceImpl implements StudentService {
        
    
        StudentDao dao = new StudentDaoImpl();
    
        //登陆
        @Override
        public boolean login(int uid, String pwd) {
        
            return dao.login(uid, pwd);
        }
    
        // 注册
        @Override
        public boolean addLogin(int uid, String pwd){
        
            return dao.addLogin(uid, pwd);
        }
    
        // 查询所有学生
        @Override
        public List<Student> getAllStudents() {
        
            return dao.getAllStudents();
        }
    
        // 分页查询
        @Override
        public List<Student> queryStudentsByPageNo(int current, int pageSize) {
        
            return dao.queryStudentByPage(current,pageSize);
        }
    
        // 删除学生
        @Override
        public Student deleteStudent(int sno){
        
            return dao.deleteStudent(sno);
        }
    
        // 修改学生信息，要先根据学号查询学生信息
        public Student queryStudentBySno(int sno) {
        
            return dao.queryStudentBySno(sno);
    
        }
    
        //更改学生信息
        public int updateStudentBySno(int sno, Student stu) {
        
            return dao.updateStudentBySno(sno,stu);
        }
        
        //查询总条数
        @Override
        public int getTotalCount() {
        
            return dao.getTotalCount();
        }
    
        @Override
        public int addStudent(Student student) {
        
            return dao.addStudent(student);
        }
        
    }

#### （3）数据访问层dao ####

##### ① 接口（StudentDao.java） #####

package com.stu.dao;
    
    import java.util.List;
    
    import com.stu.po.Student;
    
    public interface StudentDao {
        
    
        public boolean login(int uid ,String pwd);
    
        public boolean addLogin(int uid, String pwd);
    
        public List<Student> getAllStudents();
    
        public List<Student> queryStudentByPage(int currentPage,int pageSize);
    
        public Student deleteStudent(int sno);
    
        public Student queryStudentBySno(int sno);
    
        public int updateStudentBySno(int sno,Student stu);
    
        //查询总数据数
        public int getTotalCount();
    
        public int addStudent(Student student);
       
    }

##### ② 接口的实现类（StudentDaoImpl.java） #####

package com.stu.dao;
    
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.ArrayList;
    import java.util.List;
    
    import com.stu.po.Student;
    import com.stu.utils.DBTools;
    
    public class StudentDaoImpl implements StudentDao {
        
    
        Connection conn = null; // 连接对象
        Statement st = null; // 语句对象
        ResultSet rs = null; // 结果集合对象
    
        @Override
        public boolean login(int uid, String pwd) {
        
            // 在这里需要连接数据库，根据int sno, String pwd这两个参数来查询student表
            // jdbc
            // 1:配置环境，下载数据库连接驱动jar文件，拷贝到项目中来
            // 2:加载驱动，根据驱动创建数据库的连接对象
    
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                // 3:执行sql语句，完成对数据库中表的数据的增删该查。必须创建一个语句对象（执行sql语句的）
                st = conn.createStatement();
    
                int count = 0;
                String sqlStr = "select * from login where uid =" + uid + " and pwd = '" + pwd + "'";
    
                rs = st.executeQuery(sqlStr);
                while(rs.next()) {
        
                    count++;
                }
                if(count>0)
                    return true;
                else
                    return false;
    
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (SQLException e) {
        
                e.printStackTrace();
            }
            return false;
        }
    
    
        @Override
        public List<Student> getAllStudents() {
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                // 3:执行sql语句，完成对数据库中表的数据的增删该查。必须创建一个语句对象（执行sql语句的）
                st = conn.createStatement();
    
                String sqlStr = "select * from student";
    
                rs = st.executeQuery(sqlStr);
    
                List<Student> allStudents = new ArrayList<Student>();
    
                while (rs.next()) {
        
                    int _sno = rs.getInt(1);
                    String _sname = rs.getString(2);
                    String _sex = rs.getString(3);
                    int _age = rs.getInt(4);
                    String _phone = rs.getString(5);
                    Student s = new Student(_sno, _sname, _sex, _age, _phone);
                    allStudents.add(s);
                }
    
                return allStudents;
    
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (SQLException e) {
        
                e.printStackTrace();
            }
    
            return null;
        }
    
    
        public List<Student> queryStudentByPage(int current, int pageSize) {
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                // 3:执行sql语句，完成对数据库中表的数据的增删该查。必须创建一个语句对象（执行sql语句的）
                st = conn.createStatement();
    
                int startPosition = current * pageSize;
    
                String sqlStr = "select * from student limit " + startPosition + "," + pageSize;
                rs = st.executeQuery(sqlStr);
                List<Student> allStudents = new ArrayList<Student>();
                while (rs.next()) {
        
                    int _sno = rs.getInt(1);
                    String _sname = rs.getString(2);
                    String _sex = rs.getString(3);
                    int _age = rs.getInt(4);
                    String _phone = rs.getString(5);
                    Student s = new Student(_sno, _sname, _sex, _age, _phone);
                    allStudents.add(s);
                }
                return allStudents;
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (SQLException e) {
        
                e.printStackTrace();
            }
    
            return null;
        }
    
        public int getTotalCount() {
        //查询总数据数
    
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                // 3:执行sql语句，完成对数据库中表的数据的增删该查。必须创建一个语句对象（执行sql语句的）
                st = conn.createStatement();
                String sql = "select count(*) from student";
                rs = st.executeQuery(sql);
                while (rs.next()){
        
                    int totalCount = rs.getInt(1);
                }
    
    
            }catch (Exception e){
        
                e.printStackTrace();
            }
            return 0;
        }
    
        @Override
        public int addStudent(Student student) {
        
    
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                st = conn.createStatement();
                String sqlStr = "insert into student values("+student.getSno()+",'" + student.getSname()+ "','" + student.getSex() +"',"+student.getAge()+",'"+student.getPhone()+"')";
                System.out.println(sqlStr);
                int result = st.executeUpdate(sqlStr);
    
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (SQLException e) {
        
                e.printStackTrace();
            }
            return 0;
        }
    
    
        @Override
        public boolean addLogin(int uid, String pwd) {
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                st = conn.createStatement();
                String sqlStr = "insert into login values(" + uid + ",'" + pwd + "')";
    
                int result = st.executeUpdate(sqlStr);
    
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (SQLException e) {
        
                e.printStackTrace();
            }
            return false;
        }
    
    
        @Override
        public Student deleteStudent(int sno) {
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                st = conn.createStatement();
                String sqlStr = "delete from student where sno = " + sno;
                System.out.println(sqlStr);
                int result = st.executeUpdate(sqlStr);
    
            } catch (Exception e){
        
                e.printStackTrace();
            }
            return null;
        }
    
        @Override
        public Student queryStudentBySno(int sno) {
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
    
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
    
                st = conn.createStatement();
    
                String sqlStr = "select * from student where sno = "+ sno;
                rs = st.executeQuery(sqlStr);
    
                if (rs.next()) {
        
                    int _sno = rs.getInt(1);
                    String _sname = rs.getString(2);
                    String _sex = rs.getString(3);
                    int _age = rs.getInt(4);
                    String _phone = rs.getString(5);
                    Student s = new Student(_sno, _sname, _sex, _age, _phone);
                    return s;
                }
    
            } catch (Exception e) {
        
                e.printStackTrace();
            }
            return null;
        }
    
    
        @Override
        public int updateStudentBySno(int sno, Student stu){
        
            try {
        
                Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
                conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
                st = conn.createStatement();
                String sql = "update student set sname= '"+stu.getSname()+"', sex='"+stu.getSex()+"', age="+stu.getAge()+", phone='"+stu.getPhone()+"' where sno="+sno;
                System.out.println(sql);
                int result = st.executeUpdate(sql);
    
            } catch (Exception e){
        
                e.printStackTrace();
            }
            return 0;
        }
    }

[8848519781294cc498bcfbdba562c477.png]: https://img-blog.csdnimg.cn/8848519781294cc498bcfbdba562c477.png
[78591850716e4e509025f968dec836ea.png]: https://img-blog.csdnimg.cn/78591850716e4e509025f968dec836ea.png
[cda14db706974d28b716c44de46d8a7b.png_pic_center]: https://img-blog.csdnimg.cn/cda14db706974d28b716c44de46d8a7b.png#pic_center
[a2b0102f5de1459b855708229a70b6ca.png]: https://img-blog.csdnimg.cn/a2b0102f5de1459b855708229a70b6ca.png
[6a22f18495194df2989882a813dd7933.png]: https://img-blog.csdnimg.cn/6a22f18495194df2989882a813dd7933.png
[3c848d3c1e63473a922d17ec945215d5.png]: https://img-blog.csdnimg.cn/3c848d3c1e63473a922d17ec945215d5.png