Hidden Forms Session Management

PHOTO EMBED

Fri Nov 15 2024 14:34:58 GMT+0000 (Coordinated Universal Time)

Saved by @signup_returns 

//login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Login Page</title>
</head>
<body>
    <h2>Login</h2>
    <form action="LoginServlet" method="post">
        <label for="username">Username:</label>
        <input type="text" id="username" name="username" required><br><br>
        
        <label for="password">Password:</label>
        <input type="password" id="password" name="password" required><br><br>
        
        <!-- Hidden field to send a welcome message on successful login -->
        <input type="hidden" name="welcomeMessage" value="Welcome to the site!">
        
        <input type="submit" value="Login">
    </form>
</body>
</html>


//LoginServlet.java

import java.io.IOException;
import java.io.PrintWriter;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String welcomeMessage = request.getParameter("welcomeMessage"); // Getting hidden field data
        
        // Simple login validation (for demonstration only)
        if ("user".equals(username) && "password".equals(password)) {
            out.println("<h2>Login Successful!</h2>");
            out.println("<p>" + welcomeMessage + "</p>");
            out.println("<p>Welcome, " + username + "!</p>");
        } else {
            out.println("<h2>Login Failed</h2>");
            out.println("<p>Invalid username or password. Please try again.</p>");
        }
        
        out.close();
    }
}
content_copyCOPY