multi-thread（二）ThreadGroup

 

1、ThreadGroup,统一管理线程，比如优先级，interrupt等

 

public class MyThreadGroup {
    public static void main( String args[] )
        throws Exception {
        ThreadGroup tg = new ThreadGroup( "My Group" );

        MyThread1 thrd1 = new MyThread1( tg, "MyThread #1" );
        MyThread1 thrd2 = new MyThread1( tg, "MyThread #2" );
        MyThread1 thrd3 = new MyThread1( tg, "MyThread #3" );

        thrd1.start();
        thrd2.start();
        thrd3.start();

        Thread.sleep( 1000 );

        System.out.println( tg.activeCount() + " threads in thread group." );

//        Thread thrds[] = new Thread[tg.activeCount()];
//        tg.enumerate( thrds );
//        for ( Thread t : thrds )
//            System.out.println( t.getName() );

        thrd1.myStop();
        Thread.sleep( 1000 );
        System.out.println( tg.activeCount() + " threads in thread group." );
        tg.interrupt();
    }
}
class MyThread1 extends Thread {
    boolean stopped;
    MyThread1( ThreadGroup tg, String name ) {
        super( tg, name );
        stopped = false;
    }
    public void run() {
        System.out.println( Thread.currentThread() + "is starting." );
        try {
            for ( int i = 1; i < 1000; i++ ) {
                System.out.print( "." );
                Thread.sleep( 250 );
                synchronized ( this ) {
                    if ( stopped )
                        break;
                }
            }
        }
        catch ( InterruptedException exc ) {
            System.out.println( Thread.currentThread() + ": " + exc );
        }
        System.out.println( Thread.currentThread() + "is end." );
    }
    synchronized void myStop() {
        stopped = true;
    }
}