public class WindowSell2 {

    private int num=0;

    public synchronized void increade() throws InterruptedException{
        while (num != 0){
            this.wait();
        }
        num++;
        System.out.println("当前线程是"+Thread.currentThread().getName()+"num="+num);
        this.notifyAll();
    }

    public synchronized void decreade() throws InterruptedException{
        while (num == 0){
            this.wait();
        }
        num--;
        System.out.println("当前线程是"+Thread.currentThread().getName()+"num="+num);
        this.notifyAll();
    }

}

public class MainTest {
    public static void main(String[] args) {

       /**
         *
         * 两个线程进行操作
         *
         *
         *
         *
         */

        WindowSell2 windowSell2 = new WindowSell2();
        new Thread(()->{
            try {
                for (int i = 0; i < 12; i++) {
                    windowSell2.increade();
                }


            }catch (InterruptedException e){

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

        new Thread(()->{
            try {
                for (int i = 0; i < 12; i++) {
                    windowSell2.decreade();
                }


            }catch (InterruptedException e){

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

        new Thread(()->{
            try {
                for (int i = 0; i < 12; i++) {
                    windowSell2.decreade();
                }


            }catch (InterruptedException e){

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


    }
}

当前线程是Anum=1
当前线程是Bnum=0
当前线程是Anum=1
当前线程是Bnum=0
当前线程是Anum=1
当前线程是Bnum=0
当前线程是Anum=1
当前线程是Bnum=0
当前线程是Anum=1
当前线程是Cnum=0
当前线程是Anum=1
当前线程是Bnum=0
当前线程是Anum=1
当前线程是Cnum=0
当前线程是Anum=1