Future task - cancel(true) raz dziala raz nie.

Mam do stworzenia prosty serwer TCP na uczelnie. Obsługę zleceń zrealizowac w postaci FutureTask.

public class Server extends Thread{
	JTextArea consol;
	DefaultListModel<String> list;
	ServerSocket srv;
	ExecutorService exec;
	Map<Integer,Future<Socket>> tasks;
	
	public Server(int port, JTextArea consol,DefaultListModel<String> list){
		try {
			srv = new ServerSocket(port);
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		this.consol = consol;
		this.list = list;
		exec = Executors.newCachedThreadPool();
		tasks = new HashMap<>();
		start();
	}
	
	public void run(){
		consol.append("Start Server");
		int counter = 0;
		while(true){
			try {
				tasks.put(counter, exec.submit(new Task(srv.accept(),consol,counter)));
				consol.append("Client no."+(counter)+" was connected\n");
				list.addElement("Client no."+counter);
				System.out.println(tasks);
				counter++;
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	public void stopTask(int i){
		System.out.println(i);
		Future<Socket> task = tasks.get(i);
		task.cancel(true);
		
	}
	
}

a zadanie wyglada nastepujaco

public class Task implements Callable<Socket>{
	Socket soc;
	DataInputStream in;
	DataOutputStream out;
	JTextArea consol;
	int id;
	
	String actual;
	
	public Task(Socket soc, JTextArea consol, int id){
		this.soc = soc;
		this.consol = consol;
		this.id= id;
	}
	
	@Override
	public Socket call() throws IOException {
			in = new DataInputStream(soc.getInputStream());
			out = new DataOutputStream(soc.getOutputStream());
	
		while(true){

			if(Thread.currentThread().isInterrupted()){
				consol.append("Client no."+id+" was cancelled\n");
				break;
			}
			consol.append("Client "+id+" send: "+in.readUTF()+"\n");
		}
		
		return soc;
	}

}

Problem jest mianowicie taki że nie zawsze po cancel(true) wywoluje interrupted w zadaniu przez co nie zawsze moge go wyłaczyc przed jego skonczeniem.
Jak zmusic by zawsze po wywolaniu cancel(true). wychodzil mi z whila w tasku...