public void cosumeProduct() throws Exception{
        synchronized (waiter) {
            Product product = waiter.getProduct();
            if(product!=null){
                System.out.println("消费者消费 production:" +product.getId());
                
                Thread.sleep(CONSUME_TIME);
                
//                waiter.addProduct(null);
                System.out.println("消费者消费 production:" +product.getId()+"完毕") ;
                waiter.notifyAll();
            }
            
            else{
                System.out.println("没货了");
                waiter.wait();
            }
            
        }
        
    }