我想用两个button,btn1执行jprogressbar的开始,btn2暂停,代码写出来但没有执行,希望高手指教

import java.awt.BorderLayout;


public class StopThreadTest extends JFrame implements Runnable{

	private JPanel contentPane;
    private boolean running;
	private JProgressBar progressBar;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					StopThreadTest frame = new StopThreadTest();
					frame.setVisible(true);
					new Thread(frame).start();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public StopThreadTest() {
		super();
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 450, 300);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		progressBar = new JProgressBar();
		progressBar.setBounds(132, 64, 146, 20);
		progressBar.setStringPainted(true);
		progressBar.setIndeterminate(false);
		contentPane.add(progressBar);
		
		JButton btnStart = new JButton("start");
		btnStart.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				do_bottun_true(e);
			}
		});
		btnStart.setBounds(73, 139, 117, 29);
		contentPane.add(btnStart);
		
		JButton btnStop = new JButton("stop");
		btnStop.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				do_button_false(e);
			}
		});
		btnStop.setBounds(227, 139, 117, 29);
		contentPane.add(btnStop);
	}
	protected void do_bottun_true(ActionEvent e){
		this.running=true;
	}
	protected void do_button_false(ActionEvent e){
		this.running=false;
	}

	@Override
	public void run() {
		// TODO Auto-generated method stub
		
		while(running){
			for(int i=0;i<=100;i++){
				try {
					Thread.sleep(100);
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				progressBar.setValue(i);
			}
			progressBar.setString("安装完成");
		}
	}
}