Java ThreadGroup isDestroyed()用法及代碼示例

public boolean isDestroyed()

class NewThread extends Thread 
{
    NewThread(String threadname, ThreadGroup tg)
    {
        super(tg, threadname);
    }
    public void run()
    {
        for(int i = 0;i < 10;i++) 
        {
            i++;
        }
        System.out.println(Thread.currentThread().getName() + " completed executing");
    }
}
public class ThreadGroupIsDestroyedExp 
{
    public static void main(String arg[]) throws InterruptedException,
        SecurityException, Exception
    {
        // creating a parent threadGroup
        ThreadGroup tg1 = new ThreadGroup("Parent thread");
        // creating a child threadGroup 
        ThreadGroup tg2 = new ThreadGroup(tg1, "Child thread");

        // creating a thread 
        NewThread t1 = new NewThread("Thread-1", tg1);
        System.out.println("Starting of Thread-1");
        t1.start();

       // creating another thread 
        NewThread t2 = new NewThread("Thread-2", tg2);
        System.out.println("Starting of Thread-2");
        t2.start();

        if (tg1.isDestroyed() == true)
            System.out.println("Group is destroyed");
        else
            System.out.println("Group is not destroyed");
    }
}

Starting of Thread-1
Starting of Thread-2
Group is not destroyed
Thread-1 completed executing
Thread-2 completed executing