java.lang.ThreadGroup.enumerate(Thread[] list)方法實例

java.lang.ThreadGroup.enumerate(Thread[] list) 方法複製該線程組及其子組中的所有活動線程到指定的數組。

聲明

以下是**java.lang.ThreadGroup.enumerate()**方法的聲明

public int enumerate(Thread[] list)

參數

• list -- 此是一個數組，把線程列表。

返回值

此方法返回放入數組中的線程的數目。

異常

• SecurityException -- 如果當前線程沒有權限來枚舉此線程組。

例子

下面的例子顯示java.lang.ThreadGroup.enumerate()方法的使用。

package com.yiibai;

import java.lang.*;

public class ThreadGroupDemo implements Runnable
{
public static void main(String[] args) {
ThreadGroupDemo tg = new ThreadGroupDemo();
tg.func();
}

public void func() {
try {
// create a parent ThreadGroup
ThreadGroup pGroup = new ThreadGroup("Parent ThreadGroup");

     // create a child ThreadGroup for parent ThreadGroup
     ThreadGroup cGroup = new ThreadGroup(pGroup, "Child ThreadGroup");

     // create a thread
     Thread t1 = new Thread(pGroup, this);
     System.out.println("Starting " + t1.getName() + "...");
     t1.start();

     // create another thread
     Thread t2 = new Thread(cGroup, this);
     System.out.println("Starting " + t2.getName() + "...");
     t2.start();

     // returns the number of threads put into the array
     Thread\[\] list = new Thread\[pGroup.activeCount()\];
     int count = pGroup.enumerate(list);
     for (int i = 0; i < count; i++) {
        System.out.println("Thread " + list\[i\].getName() + " found");
     }

     // block until the other threads finish
     t1.join();
     t2.join();
  }
  catch (InterruptedException ex) {
     System.out.println(ex.toString());
  }

}

// implements run()
public void run() {

  for(int i = 0; i < 1000; i++) {
     i++;
  }
  System.out.println(Thread.currentThread().getName() + 
  " finished executing.");

}
}

讓我們來編譯和運行上面的程序，這將產生以下結果：

Starting Thread-0...
Starting Thread-1...
Thread Thread-0 found
Thread Thread-1 found
Thread-0 finished executing.
Thread-1 finished executing.