TCP Chat in Java

Project Overview

This project is a simple TCP-based chat application implemented in Java. It consists of a server and multiple clients that can connect to the server to exchange messages. The application demonstrates basic concepts of networking, multithreading, and socket programming in Java.

Features

• Multiple clients can connect to the server and communicate with each other.
• Each client can set a username upon connection.
• Clients can change their username using the /user command.
• Clients can disconnect from the chat using the /quit command.
• Messages from clients are broadcasted to all connected clients.

Key Concepts Used

1. Socket Programming: The project uses Java's Socket and ServerSocket classes to handle client-server communication.
2. Multithreading: The server can handle multiple clients concurrently using the ExecutorService for thread management.
3. I/O Streams: The application uses BufferedReader and PrintWriter for reading from and writing to sockets.
4. ExecutorService: The Executors.newCachedThreadPool() is used to manage a pool of threads for handling multiple client connections.
5. Synchronization: Proper handling of shared resources (like the list of connected clients) to ensure thread safety.

My Learnings

1. Networking Basics: Understanding how TCP/IP works and how to establish a connection between a client and a server.
2. Concurrency in Java: Implementing a multithreaded server to handle multiple clients simultaneously.
3. Exception Handling: Managing I/O exceptions and ensuring the server and client can handle unexpected disconnections gracefully.
4. Command Handling: Parsing and executing commands from clients, such as changing usernames or quitting the chat.
5. Resource Management: Ensuring proper closing of sockets and streams to prevent resource leaks.

How to Run

Server

1. Compile and Run the Server.java file:

   javac Server.java
   java Server
   

Client

2. Compile and Run the Client.java file:

   javac Client.java
   java Client
   
   

Usage

• When the client connects to the server, it will be prompted to enter a username.
• To change the username, type /user new_username.
• To quit the chat, type /quit.

Future Enhancements

• Improved User Input Validation: Ensure usernames are unique and valid, and sanitize all inputs to prevent malicious commands.
• Enhanced User Interface: Develop a graphical user interface (GUI) for a more user-friendly experience.
• Private Messaging: Add functionality for clients to send private messages to specific users.
• Persistence: Implement a database to store chat history and user information.

Acknowledgments

• Inspired by basic chat applications and tutorials on socket programming in Java.