[appA] Replacing Thread with single threaded executor

import java.io.*;

import java.net.Socket;

import java.util.*;

import java.util.concurrent.*;

import static javax.sound.midi.ShortMessage.*;

    userName = name;

    // open connection to the server

    try {

      Socket sock = new Socket("127.0.0.1", 4242);

      out = new ObjectOutputStream(sock.getOutputStream());

      in = new ObjectInputStream(sock.getInputStream());

      Thread remote = new Thread(new RemoteReader());

      remote.start();

      Socket socket = new Socket("127.0.0.1", 4242);

      out = new ObjectOutputStream(socket.getOutputStream());

      in = new ObjectInputStream(socket.getInputStream());

      ExecutorService executor = Executors.newSingleThreadExecutor();

      executor.submit(new RemoteReader());

    } catch (Exception ex) {

      System.out.println("Couldn’t connect-you’ll have to play alone.");

    }