About

This project is a client-server system implemented in Java using TCP sockets. The system allows users to authenticate and participate in a text-based game. The server handles user connections, authentication, team formation, and game management. The system uses TCP sockets in Java to allow users to authenticate and play text-based games with each other. The main components of the system are:

• Game.java: Represents a game instance and requires a specified number of connected players to start. It handles the game logic and execution.

• Client.java: Users connect to the system using Java client code. They first authenticate, then enter a queue for the game, and finally play the game until completion.

• Server.java: The server accepts and authenticates user connections. It forms teams of players for the game and assigns a thread from a thread pool to create and manage each game instance.

Additional Implemented Features

Fault Tolerance

The implementation includes fault tolerance to handle broken connections when users are queuing and waiting for the game to start. A protocol between the client and server allows clients to resume broken connections without losing their position in the game wait queue. Each player is assigned a token to facilitate this process.

Concurrency

Concurrency is a crucial aspect of the project. The design adheres to the following goals:

• Eliminate race conditions in accessing shared data structures and synchronization between threads.
• Custom implementations should be used for thread-safe data structures instead of relying on Java's concurrent collection classes from java.util.concurrent.locks.
• Minimize thread overhead by avoiding unnecessary thread creation and termination. The number of threads should be kept to a minimum to scale the system efficiently.

User Registration and Authentication

The project provides the option for user registration using a sub-protocol. Registration data can be persisted in a file or provided via a file. Authentication can be decoupled from game playing, allowing players to send their credentials once and participate in multiple game instances.

Setup and execution

This guide provides instructions on how to run the Server.java and Client.java classes of the client-server system.

Prerequisites

Before running the system, ensure that you have the following:

- Java Development Kit (JDK) installed on your machine.
- The compiled .class files for Server.java and Client.java.

Server

To run the server, follow these steps:

1. Open a terminal or command prompt.

2. Navigate to the directory where the Server.class file is located.

Run the following command to start the server:

java Server <port>

Replace with the desired port number for the server to listen on.

Client

To run the client, follow these steps:

1. Open a terminal or command prompt.
2. Navigate to the directory where the Client.class file is located.
3. Run the following command to start the client:

java Client <serverIP> <port>