Distributed Device Monitoring System

A Java RMI-based distributed system for monitoring and controlling multiple devices remotely. The system consists of three main components: a central registry for device management, device clients that provide remote services, and a manager application for monitoring and control.

Features

• Central Registry: Manages active device registration and discovery
• Remote Device Control: Capture screenshots and camera photos from remote devices
• Real-time Communication: Chat functionality between manager and devices
• Device Discovery: Automatic detection and listing of active devices
• Image Management: Automatic saving of captured images with timestamps

Architecture

The system uses Java RMI (Remote Method Invocation) for distributed communication:

• Central Registry: Centralized service registry for device management
• Device Clients: Remote services providing screenshot, camera, and chat capabilities
• Manager Application: Control interface for monitoring and interacting with devices

Components

1. Central Registry (Central/)

• CentralRegistry.java - Interface defining registry operations
• CentralRegistryImpl.java - Implementation of the central registry
• CentralRegistryRMI.java - RMI server for the central registry

2. Device Client (Device/)

• Device.java - Interface defining device operations
• DeviceImpl.java - Implementation of device services
• DeviceRMI.java - RMI server for device services
• libs/opencv-490.jar - OpenCV library for camera operations

3. Manager Application (Manager/)

• ManagerApp.java - Main manager application with GUI interface
• photos/ - Directory for saved camera photos
• screenshots/ - Directory for saved screenshots

Prerequisites

• Java Development Kit (JDK) 8 or higher
• OpenCV library (included in Device/libs/)
• Network connectivity between components

Usage

1. Start Central Registry

cd Central
java CentralRegistryRMI

2. Start Device Client(s)

cd Device
java DeviceRMI

3. Start Manager Application

cd Manager
java ManagerApp

How It Works

1. Device Registration: Device clients register themselves with the central registry
2. Device Discovery: Manager queries the central registry to get list of active devices
3. Remote Operations: Manager can perform operations on selected devices:
   • Capture screenshots
   • Take camera photos
   • Start chat sessions
4. File Management: Captured images are automatically saved with timestamps

Technical Details

• Communication Protocol: Java RMI over TCP/IP
• Image Format: PNG images encoded in Base64 for transmission
• Chat Protocol: Socket-based communication on port 8080
• Registry Port: Default RMI registry port 1099
• Threading: Multi-threaded chat implementation for concurrent communication

File Structure

├── Central/           # Central registry components
├── Device/           # Device client components
│   └── libs/         # OpenCV library
├── Manager/          # Manager application
│   ├── photos/       # Saved camera photos
│   └── screenshots/  # Saved screenshots
└── readme.md         # This file

Security Note

This system is designed for educational and development purposes. For production use, consider implementing proper authentication, encryption, and security measures.