Lancer un traitement à partir d'un autre

public static void main(String[] args)
{
    final Thread thread1 = new Thread()
    {
        public void run()
        {
            for (int i=0;;i++)
            {
                System.out.println("Thread_1 = "+i);
                try { Thread.sleep(1); } catch (InterruptedException e) {}
            }
        }
    };
    
    final JFrame frame1 = new JFrame();
    JButton button1 = new JButton("pause");
    
    button1.addActionListener(new ActionListener()
    {
        public void actionPerformed(ActionEvent ae)
        {
            frame1.setEnabled(false);
            thread1.suspend();
            
            final Thread thread2 = new Thread()
            {                
                @Override
                public void run()
                {
                    for (int j=0;;j++)
                    {
                        System.out.println("Thread_2 = "+j);
                        try { Thread.sleep(1); } catch (InterruptedException e) {}
                    }
                }
            };            
            
            final JFrame frame2 = new JFrame();
            
            JButton button2 = new JButton("continue");
            button2.addActionListener(new ActionListener()
            {
                @Override
                public void actionPerformed(ActionEvent ae)
                {
                    thread2.stop();
                    frame2.dispose();
                    
                    frame1.setEnabled(true);
                    thread1.resume();
                }
            });
            
            frame2.add(button2);
            frame2.setBounds(200,0,100,100); 
            
            frame2.setVisible(true);
            thread2.start();
        }
    });
    
    frame1.add(button1);
    frame1.setBounds(0,0,100,100); 
    frame1.setVisible(true);
    thread1.start();
    
    frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String[] args) throws InterruptedException
{
    final Thread thread1 = new Thread()
    {
        public void run()
        {
            for (int i=0;i<10;i++)
            {
                System.out.println("Thread_1 = "+i);
                try { Thread.sleep(500); } catch (InterruptedException e) {}
            }
        }
    };
    
    final Thread thread2 = new Thread()
    {                
        @Override
        public void run()
        {
            for (int j=0;j<10;j++)
            {
                System.out.println("Thread_2 = "+j);
                try { Thread.sleep(500); } catch (InterruptedException e) {}
            }
        }
    };  
    
    thread1.start();
    thread1.join();
    thread2.start();
}