Java application threads of communication: the classic example: the producer / consumer problem

/ ** 
* application thread communication: the classic example: the producer / consumer problem 
* 
* Producers (Productor) products to the clerk (Clerk), and consumers (Customer) removed the product from the clerk at 
* clerk once can only hold a fixed number of products (for example: 20), if producers try to produce more products, clerk 
* will be called the producer pause, if there is space to put goods store and then inform the producers to continue production; if the shop there are no products 
*, and the clerk will tell consumers wait a minute, if the store has re-notify the consumer product to take away products. 
* 
* Analysis: 
* 1. Is multi-threaded problem? , The producer thread, consumer thread 
* 2. Are there any shared data? Yes, the clerk (or product) 
* 3. How to solve the security problems thread? Synchronization mechanism, there are three ways 
* 4. Are relates to the communication thread? Is 
* 

* / 
class Clerk { 

    Private ProductCount int = 0; 
    // produce products 
    public void produceProduct the synchronized () { 

        IF (ProductCount <20 is) { 
            ProductCount ++; 
            . System.out.println (Thread.currentThread () getName () + " : begin production of the "+ productCount +" products ");

            Notify (); 

        } the else { 
            // wait for 
            the try { 
                the wait (); 
            } the catch (InterruptedException E) { 
                e.printStackTrace (); 
            } 
        } 

    } 
    // consumer 
    public void consumeProduct the synchronized () { 
        IF (ProductCount> 0) { 
            System.out.println (Thread.currentThread () getName () +. ": start spending the first" + productCount + "products"); 
            productCount--; 

            the Notify (); 
        } the else { 
            // wait for 
            the try { 
                the wait () ; 
            } the catch (InterruptedException E) {
                e.printStackTrace();
            }
        }

    }
}

class Producer extends Thread{//生产者

    private Clerk clerk;

    public Producer(Clerk clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        System.out.println(getName() + ":开始生产产品.....");

        while(true){

            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            clerk.produceProduct();
        }

    }
}

class Consumer extends Thread{//消费者
    private Clerk clerk;

    public Consumer(Clerk clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        System.out.println(getName() + ":开始消费产品.....");

        while(true){

            try {
                Thread.sleep(20);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            clerk.consumeProduct();
        }
    }
}

public class ProductTest {

    public static void main(String[] args) {
        Clerk clerk = new Clerk();

        Producer p1 = new Producer(clerk);
        p1.setName("生产者1");

        Consumer c1 = new Consumer(clerk);
        c1.setName("消费者1");
        Consumer c2 = new Consumer(clerk);
        c2.setName("消费者2");

        p1.start();
        c1.start();
        c2.start();

    }
}