Assignment - Chat Client/Server System

Project Details:

In this assignment students will explore basic socket programming, threading and GUI design using Java's network library, threading system, and swing user interface libraries to implement a basic chat client and server system. The system will allow multiple, remote users to send and receive messages across the network. On receiving a send message from a client the server component will broadcast the message to the other clients connected to the server. Consequently, the server component must be multithreaded so as to coordinate communications between the client systems.

Part A - Basic Requirements:

The basic requirements of this assignment are to implement the client and server components as discussed above. The basic protocol of the system is described below:

The operations of the client are:
• SEND_SERVER_MESG: send a basic text message to the server
• RECV_ SERVER_MESG: receive text from the server

The operations of the server are:
• RECV_CLIENT_MESG: receive text from a client
• BROADCAST_MESG: broadcast a text message received from a client to all the other clients connected to the server.

The server component should be multithreaded, and new threads should be allocated and de-allocated when clients connect and disconnect from the server. These threads can be thought of as connection handlers which manage a client socket and input, output streams. To keep track of these handlers some sort of dynamic data structure such as a vector or similar data structure can be used to coordinate access to these message handlers. The client component should be implemented as a GUI interface, and should allow users to enter text messages, display broadcast messages from the server, and send messages using a send button.

The diagram below reflects a typical implementation:

Part B - Extensions:

Basic implementation of the assignment requirements will result in only a passing grade or credit result. To get a distinction or high distinction mark several extensions are possible and include:

1) Client registration (text file based, rather than database based, including username and password)

2) Private messaging between users.

3) Blocking messages from specific users.

4) File or image transfer options.

5) Statistics functions for management at the server side (such as current users, total users, average time online, etc.).

6) Algorithms for efficient thread management.