Simple Android Binary Text Clock

Question

Hello,

I want to create a simple android binary clock but my application crashes. I use 6 textview fields: 3 for the decimal and 3 for the binary representation of the current time (HH:mm:ss). Here's the code:

import java.text.SimpleDateFormat;
import java.util.Calendar;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class Binary extends Activity implements Runnable
{
 Thread runner;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

  if (runner == null)
  { //start the song
   runner = new Thread(this);
   runner.start();
  }
    }

 @Override
 public void run()
 {
  TextView hours_dec = (TextView) findViewById(R.id.hours_dec);
  TextView mins_dec = (TextView) findViewById(R.id.mins_dec);
  TextView secs_dec = (TextView) findViewById(R.id.secs_dec);
  TextView hours_bin = (TextView) findViewById(R.id.hours_bin);
  TextView mins_bin = (TextView) findViewById(R.id.mins_bin);
  TextView secs_bin = (TextView) findViewById(R.id.secs_bin);

        SimpleDateFormat hours_sdf = new SimpleDateFormat("HH");
        SimpleDateFormat mins_sdf = new SimpleDateFormat("mm");
        SimpleDateFormat secs_sdf = new SimpleDateFormat("ss");

        Calendar cal = Calendar.getInstance();

  while (runner != null)
  {
   WaitAMoment();
   cal.getTime();

   hours_dec.setText(hours_sdf.format(cal.getTime()));
   mins_dec.setText(mins_sdf.format(cal.getTime()));
   secs_dec.setText(secs_sdf.format(cal.getTime()));

   hours_bin.setText(String.valueOf(Integer.toBinaryString(Integer.parseInt((String) hours_dec.getText()))));
   mins_bin.setText(String.valueOf(Integer.toBinaryString(Integer.parseInt((String) mins_dec.getText()))));
   secs_bin.setText(String.valueOf(Integer.toBinaryString(Integer.parseInt((String) secs_dec.getText()))));
  }

 }

 protected void WaitAMoment()
 {
  try
  {
   Thread.sleep(100);
  } catch (InterruptedException e) { };
 }
}`