DemoApp6 - Java Servlet Login Application

This is a simple Java web application that demonstrates a basic user login functionality using Jakarta Servlets. The application presents a login form, validates user credentials against hardcoded values, and then either forwards the user to a profile page upon success or displays an error message upon failure.

Features

• User login page with username and password fields.
• Server-side credential validation using a Java Servlet.
• Use of RequestDispatcher to forward to a success page (/profile).
• Use of RequestDispatcher to include the login page with an error message on failure.
• A simple profile page to welcome the logged-in user.

Technology Stack

• Backend: Java, Jakarta Servlets API
• Frontend: HTML
• Server: Any Jakarta EE compatible servlet container (e.g., Apache Tomcat, Jetty)

How It Works

The application flow is as follows:

1. Login Page: The user is first directed to index.html, which contains a simple HTML form asking for a username and password.
2. Form Submission: The form submits the credentials using the POST method to the Login servlet (mapped to /login).
3. Authentication: The Login servlet retrieves the username and password from the request. It checks them against the hardcoded values:
   • Username: priyanshu
   • Password: 123
4. Successful Login: If the credentials match, the servlet sets the username as a request attribute (user) and forwards the request and response objects to the Profile servlet (mapped to /profile).
5. Profile Page: The Profile servlet retrieves the user attribute from the request and displays a "Welcome to your profile, [username]" message.
6. Failed Login: If the credentials do not match, the Login servlet prints an error message and then includes the index.html content back into the response, effectively re-rendering the login page with an error.

Project Structure

DemoApp6
├── src/main/java
│   └── (default package)
│       ├── login.java      # Servlet for handling authentication
│       └── profile.java    # Servlet for the user profile page
└── src/main/webapp
    ├── WEB-INF
    │   └── web.xml         # Deployment Descriptor
    └── index.html          # The HTML login page

How to Run

To run this project, you will need:

• Java Development Kit (JDK) 8 or higher.
• A servlet container like Apache Tomcat 10.x or higher.
• An IDE like Eclipse or IntelliJ IDEA (optional, but recommended).

Steps:

1. Clone or download this repository.
2. Build the project into a WAR (Web Application Archive) file.
3. Deploy the generated .war file to your Apache Tomcat (or other servlet container) webapps directory.
4. Start the Tomcat server.
5. Open your web browser and navigate to http://localhost:8080/DemoApp6/ (the port and context path may vary depending on your server configuration).

Test Credentials

Use the following credentials to log in:

• Username: priyanshu
• Password: 123