Java Web项目案例之---登录注册和增删改查（jsp+servlet）

登录注册和增删改查（jsp+servlet）

（一）功能介绍

1.用户输入正确的密码进行登录

2.新用户可以进行注册

3.登录后显示学生的信息表

4.可以添加学生

5.可以修改学生已有信息

6.可以删除已有学生

7.可以显示登录的用户学号（每个页面都可以通过调用session显示）

8.可以记录浏览量

（二）页面展示

登录页面

注册页面

学生信息页面

添加页面

添加之后的学生信息表

修改页面

修改之后的学生信息表

删除之后的学生信息表

（三）项目代码

package entity;

public class Student {
     private String sno;
     private String password;
     private String name;

    public Student(String sno, String password, String name) {
        this.sno = sno;
        this.password = password;
        this.name = name;
    }

    public String getSno() {
        return sno;
    }

    public void setSno(String sno) {
        this.sno = sno;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package util;

import entity.Student;

import java.util.HashMap;

public class StudentUtil {

    public static HashMap<String, Student> map=new HashMap<String,Student>();

    static{

        map.put("101",new Student("101","123","lili"));

        map.put("102",new Student("102","123","lisa"));

        map.put("103",new Student("103","123","coco"));

        map.put("104",new Student("104","123","mark"));

    }

    public static boolean log(Student stu){

        boolean b=false;

        for(String s:map.keySet()){

            if(map.get(s).getSno().equals(stu.getSno())&&map.get(s).getPassword().equals(stu.getPassword())){

                b=true;

            }

        }

        return b;

    }

    public static boolean reg(Student stu){

        map.put(stu.getSno(),stu);

        return true;

    }

}

package servlet;

import entity.Student;

import org.omg.CORBA.Request;

import util.StudentUtil;

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("/LoginServlet")

public class LoginServlet extends HttpServlet {

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String sno=req.getParameter("sno");

        String password=req.getParameter("password");

        Student s=new Student(sno,password,null);

        boolean b=StudentUtil.log(s);

        if(b==true){

           ServletContext a=this.getServletContext();
           Object o=a.getAttribute("count");
           if(o==null){
               a.setAttribute("count",1);
           }else{
               int count=Integer.parseInt(o.toString());
               a.setAttribute("count",count+1);
           }
            HttpSession se=req.getSession();
            se.setAttribute("sno",sno);

            req.setAttribute("sno",sno);
            req.getRequestDispatcher("student.jsp").forward(req,resp); 
       }else{ req.getRequestDispatcher("error.jsp").forward(req,resp); 
           }
      } 
      @Override
      protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
             doPost(req, resp); 
        } 
      }

package servlet;

import entity.Student;

import util.StudentUtil;

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("/RegisterServlet")

public class RegisterServlet extends HttpServlet {

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String sno=req.getParameter("sno");

        String password=req.getParameter("password");

        String name=req.getParameter("name");

        StudentUtil.reg(new Student(sno,password,name));

        req.getRequestDispatcher("/index.jsp").forward(req,resp);

    }

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        doPost(req, resp);

    }

}

package servlet;

import entity.Student;

import util.StudentUtil;

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("/InsertServlet")

public class InsertServlet extends HttpServlet {

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String sno=req.getParameter("sno");

        String password=req.getParameter("password");

        String name=req.getParameter("name");

        StudentUtil.map.put(sno,new Student(sno,password,name));

        req.getRequestDispatcher("student.jsp").forward(req,resp);

    }

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        doPost(req, resp);

    }

}

package servlet;

import util.StudentUtil;

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("/UpdateServlet")

public class UpdateServlet extends HttpServlet {

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String sno=req.getParameter("sno");

        String password=req.getParameter("password");

        String name=req.getParameter("name");

        StudentUtil.map.get(sno).setName(name);

        StudentUtil.map.get(sno).setPassword(password);

        req.getRequestDispatcher("student.jsp").forward(req,resp);

    }

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        doPost(req, resp);

    }

}

package servlet;

import util.StudentUtil;

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 {

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

       String sno= req.getParameter("sno");

        StudentUtil.map.remove(sno);

        req.getRequestDispatcher("student.jsp").forward(req,resp);

    }

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        doPost(req, resp);

    }

}

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

    <title>Title</title>

</head>

<body>

<form action="LoginServlet" method="post">

    <div class="log">

        <h2>登录</h2>

        学号：<input type="text" name="sno"><br>

        密码：<input type="password" name="password"> <br>

        <input type="submit" value="确认登录">

        <a href="register.jsp" >注册</a>

    </div>

</form>

</body>

</html>

register.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

    <title>Title</title>

</head>

<body>

<form action="RegisterServlet" method="post">

    学号：<input type="text" name="sno"><br>

    密码：<input type="text" name="password"><br>

    姓名：<input type="text" name="name"><br>

    <input type="submit" value="确认">

</form>

</body>

</html>

student.jsp

<%@ page import="util.StudentUtil" %>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

    <title>Title</title>

</head>

<body>

<a href="insert.jsp">增加</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<span>用户：<%=session.getAttribute("sno")%></span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

<span>浏览量：<%=application.getAttribute("count")%></span>

<table>

    <tr>

        <td>学号</td>

        <td>密码</td>

        <td>姓名</td>

        <td></td>

    </tr>

    <%

      for(String s: StudentUtil.map.keySet()){%>

          <tr>

              <td><%=StudentUtil.map.get(s).getSno()%></td>

              <td><%=StudentUtil.map.get(s).getPassword()%></td>

              <td><%=StudentUtil.map.get(s).getName()%></td>

              <td><a href="update.jsp?sno=<%=StudentUtil.map.get(s).getSno()%>&&password=<%=StudentUtil.map.get(s).getPassword()%>&&name=<%=StudentUtil.map.get(s).getName()%>">修改</a>

                  <a href="DeleteServlet?sno=<%=StudentUtil.map.get(s).getSno()%>">删除</a></td>

          </tr>

     <% } %>

</table>

</body>

</html>

error.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

    <title>Title</title>

</head>

<body>

账户名或密码错误

<a href="index.jsp">返回登录</a>

</body>

</html>

insert.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

    <title>Title</title>

</head>

<body>

<form action="InsertServlet" method="post">

    学号：<input type="text" name="sno"/><br>

    密码：<input type="text" name="password"/><br>

    姓名：<input type="text" name="name"/><br>

    <input type="submit" value="确认添加">

</form>

</body>

</html>

update.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="UpdateServlet" method="post">
    <table>
        <tr>
            <td>学号</td>
            <td><input type="text" name="sno" value="<%=request.getParameter("sno")%>"></td>
        </tr>
        <tr>
            <td>密码</td>
            <td><input type="text" name="password" value="<%=request.getParameter("password")%>"></td>
        </tr>
        <tr>
            <td>姓名</td>
            <td><input type="text" name="name" value="<%=request.getParameter("name")%>"></td>
        </tr>
    </table>
    <input type="submit" value="确认修改">
</form>
</body>
</html>