Client.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class Client implements Runnable{
    
    private Socket client;
    private BufferedReader in;
    private PrintWriter out;
    private boolean done;


    @Override
    public void run(){
        try {
            client = new Socket("127.0.0.1", 9999); //need to change this to the server's IP address
            out = new PrintWriter(client.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(client.getInputStream()));

            InputHandler inHandler = new InputHandler();
            Thread inThread = new Thread(inHandler);
            inThread.start();

            String inMessage;
            while ((inMessage = in.readLine()) != null){
                System.out.println(inMessage);
            }
        } catch (IOException e){
            shutdown();
        }
    }

    public void shutdown(){
        done = true;
        try {
            in.close();
            out.close();
            if (!client.isClosed()){
                client.close();
            }
        } catch (IOException e){
                //ignore
        }
    }

    class InputHandler implements Runnable{

        @Override
        public void run(){
            try {
                BufferedReader inReader = new BufferedReader(new InputStreamReader(System.in));
                while (!done){
                    String message = inReader.readLine();
                    if (message.equals("/quit")){
                        out.println(message);
                        inReader.close();
                        shutdown();
                    } else {
                        out.println(message);
                    }
                }
            } catch (IOException e){
                shutdown();
            }
        }
    }

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