ProducerAndconsumer.java

/**
 * 线程之间的通信问题：生产者和消费者问题！  等待唤醒，通知唤醒
 * 线程交替执行 A B 操作同一变量  num=0
 * A num+1
 * B num-1
 */


public class ProducerAndconsumer {
    public static void main(String[] args) {
        Data data=new Data();

        new Thread(()->{ for (int i=0;i<10;i++)
        {
            try{
                data.increment();
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }

        },"A").start();

         new Thread(()->{for (int i=0;i<10;i++)
        {
            try{
                data.decrement();
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }

         },"B").start();

          new Thread(()->{for (int i=0;i<10;i++)
        {
            try{
                data.increment();
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }

         },"C").start();

           new Thread(()->{for (int i=0;i<10;i++)
        {
            try{
                data.decrement();
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
        }

         },"D").start();
    }
}


//等待，业务，通知

class Data{  //数字 资源类

    int number =0;

    // +1
    public synchronized void  increment() throws InterruptedException
    {
        while(number!=0)
        {
            //等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程  我+1 完毕了
        this.notifyAll();
    }

    public synchronized void decrement() throws InterruptedException
    {
        while(number==0)
        {
            //等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
        //通知其他线程  我-1完毕了
        this.notifyAll();
    }


}