public class SingelDoublechange {
private static final Object object=new Object();
private static int num = 0;
public static void main(String[] args) throws InterruptedException {

    Thread thread1=new Thread(new Single(num,object));
    Thread thread2=new Thread(new Double(num,object));
    thread2.start();

// Thread.sleep(10);
thread1.start();

}

}
class Single implements Runnable{
private int num;
Object object;
public Single(int num,Object object){
this.num=num;
this.object=object;
}
@Override
public void run() {

    while(num<100) {
        synchronized (object) {
          if (num % 2 != 0) {
            System.out.println(num + "是奇数");
            num++;
          }
        }
    }
}

}
class Double implements Runnable{
private int num;
Object object;
public Double(int num,Object object){
this.num=num;
this.object=object;
}
@Override
public void run() {

    while (num<100) {
        synchronized (object){
        if (num % 2 == 0) {
            System.out.println(num + "是偶数");
            num++;
        }
    }
    }
}

}

结果就是只输出一个0 然后卡住了