ThreadGroup类的getParent()方法返回线程组的父级。
语法
public final ThreadGroup getParent()
返回
此方法返回线程组的父级。
异常
SecurityException：如果当前线程无法修改线程组。
示例
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 ThreadGroupGetParentExp
{
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 Thread-1");
t1.start();
// creating another thread
NewThread t2 = new NewThread("Thread-2", tg2);
System.out.println("Starting Thread-2");
t2.start();
// print the parentThreadGroup of parent thread
System.out.println("ParentThreadGroup for " +
tg1.getName() + " is " + tg1.getParent().getName());
// print the parentThreadGroup of child thread
System.out.println("ParentThreadGroup for " +
tg2.getName() + " is " + tg2.getParent().getName());
}
}
执行上面示例代码，得到以下结果：
Starting Thread-1
Starting Thread-2
ParentThreadGroup for Parent thread is main
ParentThreadGroup for Child thread is Parent thread
Thread-1 completed executing
Thread-2 completed executing
