Java MultiThreaded Server

This project demonstrates socket-based client-server communication in Java using different threading models:

• Single-threaded server
• Multi-threaded server
• Thread-pool based server using ExecutorService

It is a beginner-friendly project focused on understanding:

• ServerSocket and Socket
• client/server communication
• input/output streams
• multi-threading in network applications
• performance comparison between raw threads and thread pools

Project Structure

• SingleThreaded/
  Basic server that handles one client at a time.

• MultiThreaded/
  Server creates a new thread per client connection.

• ThreadPool/
  Server uses ExecutorService with a fixed thread pool to manage concurrent client tasks efficiently.

Technologies Used

• Java
• Sockets
• ServerSocket
• BufferedReader
• PrintWriter
• Threads
• ExecutorService

How it works

The server binds to a port using ServerSocket and listens for incoming client connections.
When a client connects, the server accepts the connection and creates a communication channel using Socket.
The client sends messages using PrintWriter and the server reads them using BufferedReader.
The server then sends a response back using PrintWriter.

This simple architecture helps in understanding:

• how network communication works
• how concurrency is handled in Java
• why thread pools are preferred over creating one thread per request

SingleThreaded

This is the simplest implementation. It processes one client at a time.

Use case:

• educational
• basic socket learning
• low concurrency

MultiThreaded

This version creates a separate thread for each client connection.

Use case:

• basic concurrency
• learning thread lifecycle and client isolation

ThreadPool

This version uses ExecutorService and a fixed worker pool.

Use case:

• better scalability
• lower overhead than creating a new thread for every request
• more production-like server design

Run Instructions

1. Compile

javac SingleThreaded/*.java
javac MultiThreaded/*.java
javac ThreadPool/*.java

2. Run the server
SingleThreaded
java -cp SingleThreaded Server

MultiThreaded
java -cp MultiThreaded Server

ThreadPool
java -cp ThreadPool Server

3. Run the client
SingleThreaded
java -cp SingleThreaded Client

MultiThreaded
java -cp MultiThreaded Client


ThreadPool

java -cp ThreadPool Client

Key Learning Outcomes

Understanding of socket programming in Java
ServerSocket and Socket responsibilities
Role of accept() and connect()
Thread creation and concurrency basics
ExecutorService and thread-pool concepts
Resource management with sockets and streams

Notes
This project is intended for learning and demonstration.
It is not a production-grade HTTP server, but it provides a strong foundation for understanding server-side Java networking and concurrency.