Java ThreadGroup setDaemon()用法及代码示例

ThreadGroup 类的 setDaemon() 方法测试线程组是否为守护线程组。

用法:

public final void setDaemon(boolean daemon)

参数：

daemon:如果为真，则将该线程组标记为守护线程组；否则，将线程组标记为正常。

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 ThreadGroupSetDaemonExp 
{
    public static void main(String arg[]) throws InterruptedException,
        SecurityException, Exception
    {
        // creating a parent threadGroup
        ThreadGroup tg1 = new ThreadGroup("Parent thread");
        tg1.setDaemon(true);

        // creating a child threadGroup 
        ThreadGroup tg2 = new ThreadGroup(tg1, "Child thread");
        tg2.setDaemon(false);

        // creating a thread 
        NewThread t1 = new NewThread("Thread-1", tg1);
        t1.start();

       // creating another thread 
        NewThread t2 = new NewThread("Thread-2", tg2);
        t2.start();

        // returns true if this thread group is a daemon thread group
        System.out.println("Is " + tg1.getName() + " a daemon threadGroup? " + tg1.isDaemon());
        System.out.println("Is " + tg2.getName() + " a daemon threadGroup? " + tg2.isDaemon());
    }
}

输出：

Is Parent thread a daemon threadGroup? true
Is Child thread a daemon threadGroup? false
Thread-1 completed executing
Thread-2 completed executing

相关用法

注：本文由纯净天空筛选整理自 Java ThreadGroup setDaemon() 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。