A simple Java Swing application where multiple instances connect to a shared virtual grid and publish or receive each other’s positions in real time via MQTT. It demonstrates the publish–subscribe pattern using the Eclipse Paho MQTT client library and a public MQTT broker.

MQWorld is an experimentation sandbox:

• Change the topic structure
• Swap the broker
• Adjust the visuals
• Scale the world
• Extend the logic with new agents or interactions

🚀 Features

• MQTT publish--subscribe architecture using Paho.
• Real‑time synchronization of multiple clients in the same shared "world".
• Lightweight Java Swing GUI.
• Thread‑safe "Blackboard" shared‑memory model separating model, view, and controller.
• Automatic reconnection and MQTT session management.
• Easily extensible.

🛠 Run the application

java -jar target/MQWorld-1.0.jar player1
java -jar target/MQWorld-1.0.jar player2

🕹️ Controls

Key	Action
↑	Move Up
↓	Move Down
←	Move Left
→	Move Right

📁 Project Structure

• Main.java -- entry point
• Blackboard.java -- shared model
• WorldPanel.java -- renderer
• Player.java -- player model
• Publisher.java -- MQTT publisher
• Subscriber.java -- MQTT subscriber