By GokiSoft.com|
10:19 28/11/2020|
Web Component Development (SERVJSP)
[Share Code] Tìm hiểu JSTL + Cookie + Session - Lập trình JSP/Servlet
Nội dung học:
- Session
- Cookie
- JSP
- Biến môi trường
- JSTL
- ...
Web:
- Database: Server => lữu trữ dữ liệu
- Frontend:
- LocalStorage: => JS thao tác dữ liệu => cart
- Cookie: JS, Ngôn ngữ backend (PHP, Java, ASP, NodeJS, ...)
- Backend:
- Session: => Lưu trữ trên server.
====================================================================
- Thiết kế trang login
=> email: admin@aptechlearning.edu.vn & pass: 123
=> welcome
- Nếu login thành công => join login => tự động chuyển sang trang welcome
- Nếu chưa login => join welcome => tự động chuyển sang trang login.
Phân tích dự án:
- login page
- Route: /login
- JSP: login.jsp
- Servlet: LoginServlet
- welcome page
- Route: /welcome
- JSP: welcome.jsp
- Servlet: WelcomeServlet
- Hiển thị danh sách học viên
- ten, email, address#login.jsp
<%--
Document : login
Created on : Nov 28, 2020, 8:31:08 AM
Author : teacher
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>Login Page</title>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css"/>
<!-- jQuery library -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<!-- Popper JS -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<!-- Latest compiled JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<div class="panel panel-primary">
<div class="panel-heading">
<h2 class="text-center">Login Page</h2>
</div>
<div class="panel-body">
<form method="post">
<div class="form-group">
<label for="email">Email:</label>
<input required="true" type="email" name="email" class="form-control" id="email">
</div>
<div class="form-group">
<label for="pwd">Password:</label>
<input required="true" type="password" name="password" class="form-control" id="pwd">
</div>
<button class="btn btn-success">Register</button>
</form>
</div>
</div>
</div>
</body>
</html>#welcome.jsp
<%--
Document : welcome
Created on : Nov 28, 2020, 8:31:23 AM
Author : teacher
--%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@page import="lesson2.Student"%>
<%@page import="java.util.List"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>Login Page</title>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css"/>
<!-- jQuery library -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<!-- Popper JS -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<!-- Latest compiled JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<div class="panel panel-primary">
<div class="panel-heading">
<h2 class="text-center">Welcome Page
<form method="post">
<button type="submit" class="btn btn-deault">Logout</button>
</form>
</h2>
</div>
<div class="panel-body">
<table class="table table-bordered table-hover">
<thead>
<tr>
<th>STT</th>
<th>Ho & Ten</th>
<th>Email</th>
<th>Dia Chi</th>
</tr>
</thead>
<tbody>
<!-- Su dung code thuan JSP/Servlet -->
<%
List<Student> studentList = (List<Student>) request.getAttribute("studentList");
int index = 1;
for (Student student : studentList) {
%>
<tr>
<td><%=index++%></td>
<td><%=student.getFullname()%></td>
<td><%=student.getEmail()%></td>
<td><%=student.getAddress()%></td>
</tr>
<%
}
%>
<!-- Su dung JSTL -->
<c:forEach items="${studentList}" var="item" varStatus="loop">
<tr>
<td>${loop.index + 1}</td>
<td>${item.fullname}</td>
<td>${item.email}</td>
<td>${item.address}</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
</body>
</html>
#LoginServlet.java
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package lesson2;
import java.io.IOException;
import javax.jms.Session;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author teacher
*/
public class LoginServlet extends HttpServlet {
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//Check login su dung cookie
// Cookie[] cookieList = request.getCookies();
// String status = "";
//
// for (Cookie cookie : cookieList) {
// if(cookie.getName().equals("status")) {
// status = cookie.getValue();
// break;
// }
// }
//
// if(status.equals("login")) {
// response.sendRedirect("welcome");
// return;
// }
//CHeck login su dung session
HttpSession session = request.getSession();
if(session.getAttribute("status") != null) {
String status = session.getAttribute("status").toString();
if(status != null && status.equals("login")) {
response.sendRedirect("welcome");
return;
}
}
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/lesson2/login.jsp");
dispatcher.forward(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String email = request.getParameter("email");
String password = request.getParameter("password");
if(email.equalsIgnoreCase("admin@aptechlearning.edu.vn") && password.equals("123")) {
//login success
//luu thong tin da dang
//Su dung Cookie => Quan ly luu tru du lieu
// Cookie cookie = new Cookie("status", "login");
// response.addCookie(cookie);
//Su dung Session => Quan ly luu tru du lieu
HttpSession session = request.getSession();
session.setAttribute("status", "login");
response.sendRedirect("welcome");
} else {
//login fail
response.sendRedirect("login");
}
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
#Student.java
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package lesson2;
import java.io.Serializable;
/**
*
* @author teacher
*/
public class Student implements Serializable{
String fullname, email, address;
public Student() {
}
public Student(String fullname, String email, String address) {
this.fullname = fullname;
this.email = email;
this.address = address;
}
public String getFullname() {
return fullname;
}
public void setFullname(String fullname) {
this.fullname = fullname;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
#WelcomeServlet.java
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package lesson2;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author teacher
*/
public class WelcomeServlet extends HttpServlet {
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//Check login su dung cookie
// Cookie[] cookieList = request.getCookies();
// String status = "";
//
// for (Cookie cookie : cookieList) {
// if(cookie.getName().equals("status")) {
// status = cookie.getValue();
// break;
// }
// }
//
// if(!status.equals("login")) {
// response.sendRedirect("login");
// return;
// }
//CHeck login su dung session
HttpSession session = request.getSession();
String status = session.getAttribute("status").toString();
if(status == null || !status.equals("login")) {
response.sendRedirect("login");
return;
}
List<Student> studentList = new ArrayList<>();
//fake du lieu
studentList.add(new Student("TRAN VAN A", "a@gmail.com", "Ha Noi"));
studentList.add(new Student("TRAN VAN B", "b@gmail.com", "Ha Noi"));
studentList.add(new Student("TRAN VAN C", "c@gmail.com", "Nam Dinh"));
studentList.add(new Student("TRAN VAN D", "d@gmail.com", "Ninh Binh"));
studentList.add(new Student("TRAN VAN E", "e@gmail.com", "Hai Duong"));
request.setAttribute("studentList", studentList);
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/lesson2/welcome.jsp");
dispatcher.forward(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession();
session.removeAttribute("status");
response.sendRedirect("login");
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
Phản hồi từ học viên
5
(Dựa trên đánh giá ngày hôm nay)