小编ros*_*dhb的帖子

我是线程的初学者.我不确切地知道线程对象调用sleep方法的三种不同类型的方式有什么区别.还可以请说明在哪种类型的情况下使用睡眠方法的方式存在限制

代码如下

    // implementing thread by extending THREAD class//

class Logic1 extends Thread
{
    public void run()
    {
        for(int i=0;i<10;i++)
        {
            Thread s = Thread.currentThread();
            System.out.println("Child :"+i);
            try{
                s.sleep(1000);              // these are the three types of way i called sleep method
                Thread.sleep(1000);         //      
                this.sleep(1000);           //
            } catch(Exception e){

            }
        }
    }
}

class ThreadDemo1 
{
    public static void main(String[] args)
    {
        Logic1 l1=new Logic1();
        l1.start();
    }
}

我试图创建一个五个线程,因此如果一个线程在一个对象上调用synchronized方法(在这种情况下是objsyn),那么所有其他线程应该等到线程完成对象.因此输出应该按顺序从线程1到线程5.但输出结果不合时宜.

    class synctest extends Thread
    {
        public synchronized  void  display()
        {
            try{Thread.sleep(5000*((long)(Math.random())));}
            catch(Exception e){}

            System.out.println("From synchornized thread    "+ Thread.currentThread().getName());   
        } 
        public synchronized void run()
        {
            synctest objsyn = new synctest();
            objsyn.display();
        }
        public static void main(String args[])
        {
            synctest objsy = new synctest();
            Thread t1 = new Thread(objsy,"Thread 1");
            Thread t2 = new Thread(objsy,"Thread 2");
            Thread t3 = new Thread(objsy,"Thread 3");
            Thread t4 = new Thread(objsy,"Thread 4");
            Thread t5 = new Thread(objsy,"Thread 5");
            t1.start();
            t2.start();
            t3.start();
            t4.start();
            t5.start();
        }
        }