import java.awt.*;
import java.awt.event.*;
public class TestGUIThread {    
    public static void main(String args[]) throws Exception{
        
        Frame f = new Frame();
        Button b = new Button("Press Me!");
        MyMonitor mm = new MyMonitor();
        b.addActionListener(mm);
        f.addWindowListener(mm);    
        f.add(b,"Center");    
        f.setSize(100,60);
        f.setVisible(true);
        MyThreadViewer.view();
    }
}

class MyMonitor extends WindowAdapter implements ActionListener{
    public void actionPerformed(ActionEvent e){
        MyThreadViewer.view();    
    }
}

class MyThreadViewer{
    public static void view(){
        Thread current = Thread.currentThread();
        System.out.println("当前线程名称: " + current.getName());
        int total = Thread.activeCount();
        System.out.println("活动线程总数: " + total + "个");
        Thread[] threads = new Thread[total];        
        current.enumerate(threads);
        for(Thread t : threads){
            String role = t.isDaemon()?"后台线程 ":"用户线程 ";
            System.out.println("   -" + role + t.getName());    
        }    
        System.out.println("----------------------------------");
    }    
}