ServerSocketExecutor.java

public class ServerSocketExecutor implements Runnable, Observer {
    private static final Logger logger = getLogger(ServerSocketExecutor.class.getName());
    ExecutorService executor;
    ServerSocketListener serverSocket;
    BlockingQueue<Socket> queue;
    List<Integer> listeningPorts = Collections.emptyList();

    public ServerSocketExecutor(List<Integer> listeningPorts) {
        this.listeningPorts = listeningPorts;
        executor = Executors.newFixedThreadPool(listeningPorts.size());
    }

    public void run() {
        // Create new listening thread for each port to listen on
        for (Integer port : listeningPorts) {
            try {
                serverSocket = new ServerSocketListener(port);
                serverSocket.addObserver(this);
                executor.execute(serverSocket);

            } catch (IOException e) {
                logger.error(e);
            }
        }
    }

    public void publishToQueue(BlockingQueue<Socket> queue) {
        this.queue = queue;
    }

    public void update(Observable o, Object socket) {
        try {
            queue.put((Socket) socket);
        } catch (InterruptedException e) {
            logger.error(e);
        }
    }
}