public class ResponseQueue {

private ResponseQueue(){}

private BlockingQueue<Message> queue = new SynchronousQueue<Message>();

public synchronized Message poll()
{
    Log log = LogFactory.getLog(this.getClass());

    Message response = null;
    do {
        try {
            response = queue.take();
            if(response!=null)
            {return response;}
            else {
                log.error("null");
            }

        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    } while ((response == null));

    return null;

}

public synchronized  boolean push(Message response)
{
    Log log = LogFactory.getLog(this.getClass());
    boolean done = false;
    while(!done){
        System.out.println("tryin");
        queue.add(response);
        if(!queue.isEmpty())
            {done = true;
        return true;}

    }
    return false;

}



private static class LazyHolder {
    private static final ResponseQueue INSTANCE = new ResponseQueue();
}

public static ResponseQueue getInstance() {
    return LazyHolder.INSTANCE;
}

public class TestSendReceiveFromResponseQueue extends TestCase{
    ResponseQueue respQueue;

@Override
protected void setUp() throws Exception {
    super.setUp();
    respQueue= ResponseQueue.getInstance();
}

class Receiver implements Runnable {
    Message message;

    @Override
    public void run() {
        message = null;
        while(true){
        while (message==null) {
            message = respQueue.poll();

        }
        }
        }

}

class Sender implements Runnable {
    Message message = new Message();

    @Override
    public void run() {
    message.setResponse("test");


    respQueue.push(message);

    }

}

public void test() {
    Receiver r = new Receiver();
    new Thread(r).start();

    Sender s = new Sender();
    new Thread(s).start();

    while(r.message==null)
    {

    }
    assertEquals(true, r.message.getResponse().equals("test"));
}
}

public void run() {
    Message message = null; //This line here creates a new local variable called message!
    ...
}

message = null;