Java线程组activeGroupCount()方法
ThreadGroup类的
activeGroupCount()方法返回此线程组中活动组的数量的估计值，并且它的子组。返回值只是一个估计值，因为在此方法遍历内部数据结构时，线程组的数量可能会动态变化。
语法
public int activeGroupCount()
返回
它返回以该线程组为祖先的活动线程组的数量。
示例
class NewThread extends Thread
{
NewThread(String threadname, ThreadGroup tg)
{
super(tg, threadname);
}
public void run()
{
for (int i = 0; i < 10; i++)
{
try
{
Thread.sleep(10);
}
catch (InterruptedException ex) {
System.out.println(Thread.currentThread().getName()
+ " interrupted");
}
}
System.out.println(Thread.currentThread().getName() +
" completed executing");
}
}
public class ThreadGroupActiveGroupExp
{
public static void main(String arg[])
{
// creating the thread group
ThreadGroup tg1 = new ThreadGroup("parent thread group");
ThreadGroup tg2 = new ThreadGroup(tg1, "child threadGroup");
ThreadGroup tg3 = new ThreadGroup(tg1, "child threadGroup");
// creating the threads
NewThread t1 = new NewThread("Thread-1", tg1);
System.out.println(t1.getName() + " starts");
// this will call the run() method
t1.start();
// checking the number of active thread
System.out.println("Number of active thread group: "
+ tg1.activeGroupCount());
}
}
输出:
Thread-1 starts
Number of active thread group: 2
Thread-1 completed executing
