ThreadGroup类的parentOf()方法测试线程组是线程组的参数还是其祖先线程组之一。
语法
public final boolean parentOf(ThreadGroup g)
参数
g：它是一个线程组
返回
如果调用线程是组的父级，则返回true。 否则，它返回false。
示例
class NewThread extends Thread
{
NewThread(String threadname, ThreadGroup tg)
{
super(tg, threadname);
}
public void run()
{
for (int i = 0; i < 5; i++)
{
try
{
Thread.sleep(10);
}
catch (InterruptedException ex){
}
}
System.out.println(Thread.currentThread().getName() + " completed executing");
}
}
public class ThreadGroupParentOfExp
{
public static void main(String arg[]) throws InterruptedException,
SecurityException, Exception
{
// creating the thread group
ThreadGroup g1 = new ThreadGroup("Parent thread");
ThreadGroup g2 = new ThreadGroup(g1, "Child thread");
// creating a thread
NewThread t1 = new NewThread("Thread-1", g1);
System.out.println(t1.getName()+" starts");
t1.start();
// creating another thread
NewThread t2 = new NewThread("Thread-2", g1);
System.out.println(t2.getName()+" starts");
t2.start();
// checking who is parent thread
boolean isParent = g2.parentOf(g1);
System.out.println(g2.getName() + " is the parent of " + g1.getName() +": "+ isParent);
isParent = g1.parentOf(g2);
System.out.println(g1.getName() + " is the parent of " + g2.getName() +": "+ isParent);
}
}
执行上面示例代码，得到以下结果：
Thread-1 starts
Thread-2 starts
Child thread is the parent of Parent thread: false
Parent thread is the parent of Child thread: true
Thread-1 completed executing
Thread-2 completed executing
