open_in_new content_copy 
//Login Servlet

//index.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 Page</h2>
    <form action="Logininit" method="post">
        <label for="username">Username:</label><br>
        <input type="text" id="username" name="username" required><br><br>
        <label for="password">Password:</label><br>
        <input type="password" id="password" name="password" required><br><br>
        <input type="submit" value="Login">
    </form>
</body>
</html>


//LoginServletInit.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("/Logininit")
public class LoginServletInit extends HttpServlet {
    private static final long serialVersionUID = 1L;
    
    // Define valid credentials directly in the servlet
    private final String validUsername = "ramesh";
    private final String validPassword = "fattah";

    public LoginServletInit() {
        // Default constructor
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        if (validUsername.equals(username) && validPassword.equals(password)) {
            out.println("<html><body>");
            out.println("<h1>Login successful! Welcome, " + username + "</h1>");
            out.println("</body></html>");
        } else {
            out.println("<html><body>");
            out.println("<h1>Invalid credentials. Please try again.</h1>");
            out.println("<a href=\"index.html\">Go back to Login</a>");
            out.println("</body></html>");
        }
        out.close();
    }
}