类ThreadGroup

Java中使用ThreadGroup来表示线程组，它可以对一批线程进行分类管理，Java允许程序直接对线程组进行控制。

默认的情况下，所有的线程都属于主线程组。

public final ThreadGroup getThreadGroup()

我们也可以给线程设置分组

Thread(ThreadGroup group,Runnable target,String name)

public class IntegerDemo {
	public static void main(String[] args) {

		MyRunnable my = new MyRunnable();

		Thread t1 = new Thread(my, "hello");
		Thread t2 = new Thread(my, "world");

		ThreadGroup tg1 = t1.getThreadGroup();
		ThreadGroup tg2 = t2.getThreadGroup();

		System.out.println(tg1.getName());// main
		System.out.println(tg2.getName());// main

		System.out.println(Thread.currentThread().getThreadGroup().getName());// main
	}
}

class MyRunnable implements Runnable {

	@Override
	public void run() {
		// TODO Auto-generated method stub

		for (int i = 0; i < 100; i++) {
			System.out.println(Thread.currentThread().getName() + ":" + i);
		}
	}
}

void setDaemon(boolean daemon);// 更改此线程组的后台程序状态。

public class IntegerDemo {
	public static void main(String[] args) {
		method();
	}

	private static void method() {
		ThreadGroup tg = new ThreadGroup("新的线程组");

		MyRunnable my = new MyRunnable();

		Thread t1 = new Thread(tg, my, "hello");
		Thread t2 = new Thread(tg, my, "world");

		tg.setDaemon(true);// 更改此线程组的后台程序状态。

		ThreadGroup tg1 = t1.getThreadGroup();
		ThreadGroup tg2 = t2.getThreadGroup();

		System.out.println(tg1.getName());// 新的线程组
		System.out.println(tg2.getName());// 新的线程组

		System.out.println(Thread.currentThread().getThreadGroup().getName());// main
	}
}

class MyRunnable implements Runnable {

	@Override
	public void run() {
		// TODO Auto-generated method stub

		for (int i = 0; i < 100; i++) {
			System.out.println(Thread.currentThread().getName() + ":" + i);
		}
	}
}