Multi-Threaded-Secure-Chat-Application

Part 1: Server and Client Setup

1.1 Server Initialization

• Developed a robust Java program for a simple server capable of listening on a specified port.
• Implemented error handling mechanisms to gracefully handle unexpected situations.

1.2 Client Connection

• Created a corresponding client program that establishes a socket connection with the server.
• Ensured secure and reliable communication between the client and server.
• Implemented a message exchange where the client sends a message, and the server responds with a confirmation message.

Part 2: Multi-Threaded Server

2.1 Multi-Threaded Architecture

• Extended the server functionality to become multi-threaded, capable of handling multiple client connections concurrently.
• Implemented a robust mechanism for managing and coordinating threads, ensuring efficient communication.

2.2 Simple Protocol Implementation

• Developed a simple communication protocol allowing clients to send and receive messages through the server.
• Decided on a standard format for messages exchanged between clients and the server.

2.3 Dynamic Thread Management

• Implemented a dynamic thread management system, allowing the server to adapt to varying loads and optimize resource usage.

2.3.1 Thread Pool Implementation

• Enhanced the multi-threaded server by implementing a thread pool for efficient thread reuse and resource management.

Part 3: Secure Chat Application Enhancement

3.1 Chat Server Implementation

• Transformed the multi-threaded server into a full-fledged chat server.
• Enabled clients to connect and engage in real-time conversations through the server.
• Implemented broadcasting functionality to distribute messages to all connected clients.

3.2 Advanced Features

• Enhanced the chat application with features such as nickname assignment and private messaging.

3.3 Socket-level Encryption

• Implemented socket-level encryption to secure the communication channel between the server and clients, ensuring confidentiality and integrity of messages.

3.4 Error Handling and Resilience

• Developed advanced error handling mechanisms and resilience features to recover from network errors, ensuring a stable and uninterrupted chat experience.

Part 4: File Transfer

4.1 File Transfer Protocol Design

• Defined a robust file transfer protocol that includes specifications for file metadata, data packet structure, and error handling mechanisms.

4.2 Client-Side Implementation

• Enhanced the client-side of the application to support file selection and initiate the file transfer process.
• Implemented a user-friendly interface for selecting and sending files, allowing clients to choose files from their local storage.

4.3 Server-Side Handling

• Extended the server-side functionality to receive incoming file transfers, manage file storage, and appropriately handle file-related requests.
• Implemented mechanisms to organize and store received files on the server securely.

4.4 Error Handling

• Implemented robust error handling mechanisms to address issues that may arise during file transfers.
• Defined error codes and messages to communicate specific issues, enabling clients and the server to respond appropriately.