Producer & Consumer 生产者、消费者

//Meal.java
package producer.consumer.demo;

public class Meal {
    private final int orderNum;

    public Meal(int orderNum) {
	this.orderNum = orderNum;
    }

    public String toString() {
	return "Meal " + orderNum;
    }
}

//Chef.java
package producer.consumer.demo;

import java.util.concurrent.TimeUnit;

public class Chef implements Runnable{
    private Restaurant restaurant;
    private int count = 0;

    public Chef(Restaurant r) {
	restaurant = r;
    }

    public void run() {
	try {
	    while (!Thread.interrupted()) {
		synchronized (this) {
		    while (restaurant.meal != null)
			wait(); // ... for the meal to be taken
		}
		if (++count == 10) {
		    System.out.println("Out of food, closing");
		    restaurant.exec.shutdownNow();
		}
		System.out.println("Order up! ");
		synchronized (restaurant.waitPerson) {
		    restaurant.meal = new Meal(count);
		    restaurant.waitPerson.notifyAll();
		}
		TimeUnit.MILLISECONDS.sleep(100);
	    }
	} catch (InterruptedException e) {
	    System.out.println("Chef interrupted");
	}
    }
}

//WaitPerson.java
package producer.consumer.demo;

public class WaitPerson implements Runnable{
    private Restaurant restaurant;

    public WaitPerson(Restaurant r) {
	restaurant = r;
    }

    public void run() {
	try {
	    while (!Thread.interrupted()) {
		synchronized (this) {
		    while (restaurant.meal == null)
			wait(); // ... for the chef to produce a meal
		}
		System.out.println("Waitperson got " + restaurant.meal);
		synchronized (restaurant.chef) {
		    restaurant.meal = null;
		    restaurant.chef.notifyAll(); // Ready for another
		}
	    }
	} catch (InterruptedException e) {
	    System.out.println("WaitPerson interrupted");
	}
    }
}

//Restaurant.java
package producer.consumer.demo;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Restaurant {
    Meal meal;
    ExecutorService exec = Executors.newCachedThreadPool();
    WaitPerson waitPerson = new WaitPerson(this);
    Chef chef = new Chef(this);

    public Restaurant() {
	exec.execute(chef);
	exec.execute(waitPerson);
    }

    public static void main(String[] args) {
	new Restaurant();
    }
}

　　

from: Thinking in Java.