handler pause and resume

class  extends Handler {
    Stack<Message> s = new Stack<Message>();
    boolean is_paused = false;
    public synchronized void pause() {
        is_paused = true;
    }
    public synchronized void resume() {
        is_paused = false;
        while (!s.empty()) {
            sendMessageAtFrontOfQueue(s.pop());
        }
    }
    
    public void handleMessage(Message msg) {
        if (is_paused) {
            s.push(Message.obtain(msg));
            return;
        }else{
               super.handleMessage(msg);
               
               // ...
        }
    }
    //...
}