pubsub is a client-server application developed in Java that enables multiple clients to connect to a server and communicate through topic-based messaging. The project leverages socket programming and multithreading to ensure concurrent message handling.

• Topic-based messaging: Clients can register to topics as either publishers or subscribers.
• Multithreaded architecture: The server can handle multiple clients concurrently.
• Thread synchronization: Utilizes synchronized blocks and concurrent collections to prevent race conditions.
• Backlog System: Stores client commands during server inspection mode and executes them once the mode ends.
• Extended Server Commands:
  • kick <clientID>: Removes a client from the server.
  • export <clientID|topicID>: Saves messages to a file.
  • users: Lists all connected users.
  • clear: Deletes all messages in an inspected topic.

• Java (Sockets, Threads, Concurrency API)
• ConcurrentHashMap, ConcurrentLinkedQueue
• ExecutorService for thread management

• Java JDK 8+

javac Server.java Client.java ClientHandler.java Message.java

java Server <portNumber>

• <portNumber> should be in the range 1024-65535.

java Client <serverIP> <portNumber>

• Replace <serverIP> with localhost for local testing or the actual server IP.

• help: Displays available commands
• publish <topic>: Registers as a publisher for a topic
• subscribe <topic>: Registers as a subscriber
• send <message>: Sends a message to the topic
• list: Displays messages sent by the publisher
• listall: Displays all messages in the topic
• quit: Disconnects from the server

• show: Lists all topics
• inspect <topic>: Starts inspecting a topic
• end: Ends topic inspection
• listall: Displays all messages in a topic (during inspect mode)
• delete <messageID>: Removes a specific message (during inspect mode)
• kick <clientID>: Disconnects a client
• clear: Clears all messages from an inspected topic
• export <clientID|topicID>: Saves messages to a log file
• users: Displays all connected clients

• Edoardo Galli (0001049383) - [email protected]
• Jean Baptiste Dindane (0001100694)

This project is licensed under the MIT License - see the LICENSE file for details.

For more details on the architecture and implementation, refer to LABSO_DOCUMENTAZIONE.pdf in the docs/ directory.