Digital Clock

How to Make time textfield Runnable

class chap2 extends JFrame implements ActionListener,Runnable{
Thread runner;
JLabel lab1=new JLabel("Time ");
JTextField tf1=new JTextField(20);
chap2(){
start();repaint();

setLayout(new FlowLayout());
tf1.setEditable(false);
add(lab1);
add(tf1);

}

void get_Time(){
    Date date = new Date();
//DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
DateFormat df = new SimpleDateFormat("HH:mm:ss");
df.setTimeZone(TimeZone.getTimeZone("GMT+5"));
   //df.setTimeZone(TimeZone.getDefault());
String Timex=("" + df.format(date));
df.setTimeZone(TimeZone.getDefault());
    tf1.setText(""+Timex);
}

@Override
 public void run() {
        while (true) {
       get_Time();
        repaint();
      try { Thread.sleep(1000); }
       catch (InterruptedException e) { }
     }
    }
    public void start() {     if (runner == null) {
    runner = new Thread(this);
    runner.start();
  }
}
    public void stop() {
    if (runner != null) {
      runner.stop();
      runner = null;
    }   }
    public void paint() {
    get_Time();
  }


}