Implement Server Session pattern

[iluwatar]

The Server Session pattern is a design pattern primarily used in web development to manage user sessions on the server-side. When a user interacts with a web application, a unique session is created and maintained on the server for that user. This session stores information about the user's state and interactions with the application, such as login credentials, user preferences, and shopping cart contents.

In this pattern, the server generates a unique session identifier (session ID) for each user session, which is typically sent to the client's browser as a cookie. The client's browser then sends this session ID back to the server with each subsequent request, allowing the server to retrieve the session data and maintain continuity in the user's experience.

Key aspects of the Server Session pattern include:

• Session Creation: When a user first accesses the application, a new session is created on the server if one does not already exist.
• Session Storage: Session data is stored on the server, which can be in memory, a database, or other persistent storage mechanisms.
• Session Expiry: Sessions have a defined lifetime after which they expire, requiring re-authentication or creating a new session to ensure security.
• Session Cleanup: Periodically, the server cleans up expired sessions to free resources.

This pattern is essential for maintaining a stateful interaction between a stateless HTTP client and server, providing a personalized user experience across web requests.

Acceptance Criteria:

• The implementation should follow the architectural style and conventions outlined in the project's contribution guidelines.
• Adequate unit and integration tests must be included to ensure the pattern's functionality and reliability.
• Documentation should be provided to explain the pattern's purpose, how it was implemented, and a basic usage example.

[Ehspresso]

I would like to take this issue on.

[Ehspresso]

Hi, I have implemented the pattern. I am not sure if it is suitable. Here is the explanation of my implementation, let me know if it is acceptable and what can be changed before I continue forward.

A server starts up. The user can create a session by visiting localhost:8080/login. This stores a sessionid and user number in a map. The user can logout by visiting localhost:8080/logout. Multiple users can login and have sessions simultaneously and their user number is automatically incremented. Multiple users can be simulated by visiting localhost:8080/login on multiple browsers, or firefox's container addon. Sessions expire after 1 minute by having a user's sessionid and user number deleted from the map If a user attempts to logout after their session expired then a message is shown saying the session is null.

[iluwatar]

Sounds good @Ehspresso