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servlet① 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service① Service接口（StudentService.java）② 接口的实现类（StudentServiceImpl.java） （3）数据访问层dao① 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
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
（2）学生信息表student
（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
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)
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.Student;import com.stu.service.StudentService;import com.stu.service.StudentServiceImpl;@WebServlet("/ShowAllStudentsServlet")public class ShowAllStudentsServlet extends HttpServlet{ @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { StudentService service = new StudentServiceImpl(); HttpSession session = request.getSession(); List<Student> allStudents = service.getAllStudents(); session.setAttribute("allStudents", allStudents); response.sendRedirect("showAllStudents.jsp"); }}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)
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("/DeleteServlet")public class DeleteServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1.获取sno String sno = request.getParameter("sno"); int _sno = 0; if(sno != null && !"".equals(sno)){ _sno = Integer.parseInt(sno); } //2.执行删除 StudentService service = new StudentServiceImpl(); Student stu = service.deleteStudent(_sno); //3.跳转到列表页 request.setAttribute("stu", stu); request.getRequestDispatcher("ShowAllStudentsServlet").forward(request,response); }}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)
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;@WebServlet("/QuitServlet")public class QuitServlet extends HttpServlet{ @Override protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException { HttpSession session = request.getSession(); session.invalidate();//清空session对象中的所有属性数据内容 resp.sendRedirect("index.jsp"); }}（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; }}