ServerSocket example using ThreadPool

ClientService.java

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.Scanner;

public class ClientService {

	Socket           socket = null;
	DataInputStream  dis    = null;
	DataOutputStream dos    = null;
	Scanner          scan   = null;

	public static void main(String[] args) {
		ClientService cs = new ClientService();
		cs.run();
	}

	public void run() {
		try {
			socket = new Socket("127.0.0.1", 7777);
			dis = new DataInputStream(socket.getInputStream());
			dos = new DataOutputStream(socket.getOutputStream());
		} catch (IOException e) {
			e.printStackTrace();
		}

		while (true) {
			try {
				scan = new Scanner(System.in);
				String message = scan.nextLine();
				dos.writeUTF(message);
				String inStr = dis.readUTF();
				if (inStr != null) {
					System.out.println(inStr);
				}
				if (message.equals("bye")) {
					break;
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

		try {
			dis.close();
			dos.close();
			socket.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}

ServerService.java

import java.io.Closeable;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ServerService implements Closeable  {

	static ServerSocket serversocket = null;
	static {
		try {
			serversocket = new ServerSocket(7777);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public ServerService() {
	}

	public static void main(String[] args) {

		ExecutorService executor = Executors.newFixedThreadPool(5);
		for (int i = 0; i < 10; i++) {
			executor.submit(new RunService());
		}
	}

	@Override
    public void close() throws IOException {
	    serversocket.close();
    }
}

class RunService implements Runnable {

	Socket           socket = null;
	DataInputStream  dis    = null;
	DataOutputStream dos    = null;

	@Override
	public void run() {
		try {
			socket = ServerService.serversocket.accept();
			dis = new DataInputStream(socket.getInputStream());
			dos = new DataOutputStream(socket.getOutputStream());

			while (true) {
				String tmpStr = dis.readUTF();
				if (tmpStr != null) {
					System.out.println(tmpStr);
					dos.writeUTF("Hi " + tmpStr);
					if (tmpStr.equals("bye")) {
						System.out.println("Arrivederci");
						break;
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				dis.close();
				dos.close();
				socket.close();
			} catch (IOException e) {
				e.printStackTrace();
			}

		}

	}

}

• Added guard for Closing ServerService
• Added sending message back to ClientService
• Decreased the poolsize to see a few active threads but to see waiting a few more ClientService