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
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
mysqlmysql-connector-java8.0.21javax.servletjavax.servlet-api3.0.1providedjavax.servlet.jspjsp-api2.2provided2.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)
<!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"/></div></form></div></body></html>（2）用户注册界面 (register.jsp)
<!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)
<!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" />);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><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)
<!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)
<!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"><tableborder="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><tr><td></td><td></td><td></td><td></td><td></td></tr></table><div class = item><a href = "ShowStudentsByPageServlet?currentPage=0">首页</a><a href = "ShowStudentsByPageServlet?currentPage=">上一页</a><input type = "text" name = "currentPage" value=""/></div><div class = item><input type = "text" name = "currentPage" value="1"/><a href = "ShowStudentsByPageServlet?currentPage=">下一页</a><a href = "ShowStudentsByPageServlet?currentPage=">尾页</a></div><div class = item><a href = "ShowStudentsByPageServlet?currentPage=0">首页</a><a href = "ShowStudentsByPageServlet?currentPage=">上一页</a><input type = "text" name = "currentPage" value=""/><a href = "ShowStudentsByPageServlet?currentPage=">下一页</a><a href = "ShowStudentsByPageServlet?currentPage=">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
<!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"><tableborder="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 <tr><td></td><td></td><td></td><td></td><td></td><td><a href = "DeleteServlet?sno=">删除</a><a href = "QueryStudentBySnoServlet?sno=">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)
<!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"><div class = "updateDiv"><div class = "name">修改学生信息</div><input type="hidden" name="sno" value=""/><div class = "item"><input type = "text" name="sname" placeholder="姓名" value=""/></div><div class = "item"><input type = "text" name="sex" placeholder="性别" value=""/></div><div class = "item"><input type = "text" name="age" placeholder="年龄" value=""/></div><div class = "item"><input type = "text" name="phone" placeholder="电话" value=""/></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，javabeanprivate 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{@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doPost(req, resp);}@Overrideprotected 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{@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doPost(req, resp);}@Overrideprotected 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{@Overrideprotected 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{@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {StudentService service = new StudentServiceImpl();HttpSessionsession = 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{@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {this.doPost(req, resp);}@Overrideprotected 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snoString 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 {@Overrideprotected 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{@Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {HttpSessionsession = 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@Overridepublic boolean login(int uid, String pwd) {return dao.login(uid, pwd);}// 注册@Overridepublic boolean addLogin(int uid, String pwd){return dao.addLogin(uid, pwd);}// 查询所有学生@Overridepublic List<Student> getAllStudents() {return dao.getAllStudents();}// 分页查询@Overridepublic List<Student> queryStudentsByPageNo(int current, int pageSize) {return dao.queryStudentByPage(current,pageSize);}// 删除学生@Overridepublic 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@Overridepublic int getTotalCount() {return dao.getTotalCount();}@Overridepublic 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@Overridepublic 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;elsereturn false;} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}return false;}@Overridepublic 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;}@Overridepublic 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;}@Overridepublic 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;}@Overridepublic 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;}@Overridepublic 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;}@Overridepublic 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;}}