public void produce(Object obj){
		synchronized (this) {
			while (objs.size() == MAX) {
				System.out.println("It is full.");
				try {
					wait();
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			objs.add(obj);
			System.out.println("Produce: " + obj);
			notify();
		}
	}