Java ThreadGroup activeGroupCount()用法及代码示例

ThreadGroup 类的 activeGroupCount() 方法返回此线程组及其子组中活动组的估计数量。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。

用法

public int activeGroupCount()

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

相关用法

注：本文由纯净天空筛选整理自 Java ThreadGroup activeGroupCount() method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。