Java.lang.ThreadGroup.list() 方法

描述

java.lang.ThreadGroup.list() 方法将有关此线程组的信息打印到标准输出。 这仅对调试有用。

声明

以下是 java.lang.ThreadGroup.list() 方法的声明。

public void list()

参数

NA

返回值

此方法不返回任何值。

异常

NA

示例

下面的例子展示了 java.lang.ThreadGroup.list() 方法的使用。

package com.tutorialspoint;

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();
             
         // listing contents of parent ThreadGroup
         System.out.println("\nListing parentThreadGroup: " + pGroup.getName() + ":");
         // prints information about this thread group to the standard output
         pGroup.list();

         // listing contents of child ThreadGroup
         System.out.println("\nListing childThreadGroup : " + cGroup.getName() + ":");
         // prints information about this thread group to the standard output
         cGroup.list();

         // 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.");
   }
}  

让我们编译并运行上面的程序，这将产生下面的结果 −

Starting Thread-0...
Starting Thread-1...

Listing parentThreadGroup: Parent ThreadGroup:
java.lang.ThreadGroup[name=Parent ThreadGroup,maxpri=10]
    Thread[Thread-0,5,Parent ThreadGroup]
    Thread-1 finished executing.
Thread-0 finished executing.
java.lang.ThreadGroup[name=Child ThreadGroup,maxpri=10]
        Thread[Thread-1,5,Child ThreadGroup]

Listing childThreadGroup : Child ThreadGroup:
java.lang.ThreadGroup[name=Child ThreadGroup,maxpri=10]
    Thread[Thread-1,5,Child ThreadGroup]