java高级——生产者消费者问题

多线程是一个很重要的应用，本节讲述多线程中同步问题

public class ThreadDemo {
    public static void main(String[] args) {
        Resource r = new Resource();

        Producer p1 = new Producer(r);

        Consumer c1 = new Consumer(r);

        new Thread(p1).start();
        new Thread(p1).start();
        new Thread(c1).start();
        new Thread(c1).start();
    }
}
/*资源类*/
class Resource {
    private String name;
    private boolean flag = false;//资源存在标记
    //生产资源
    public synchronized void set(String name) {
        while (flag) {
            try {
                this.wait();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        this.name = name;
        System.out.println(Thread.currentThread().getName() + "生成者" + name);
        flag = true;
        this.notifyAll();
    }
    //消费资源
    public synchronized void get() {
        while (!flag) {
            try {
                this.wait();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        System.out.println(Thread.currentThread().getName() + "消费者" + name);
        flag = false;
        this.notifyAll();
    }
}
/*生产者类*/
class Producer implements Runnable {
    private Resource r;

    public Producer(Resource r) {
        this.r = r;
    }

    public void run() {
        while (true) {
            r.set("商品");
        }
    }
}
/*消费者类*/
class Consumer implements Runnable {
    private Resource r;

    public Consumer(Resource r) {
        this.r = r;
    }

    public void run() {
        while (true) {
            r.get();
        }
    }
}

上面的代码实现了同步外，还解决了生成一次消费一次的工厂生产问题