Update TextView with a Thread

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
</LinearLayout>

//from   w w  w.  j ava 2s  .c  o  m
package com.java2s.myapplication3.app;

import java.util.Calendar;

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

public class MainActivity extends Activity {

    TextView mClock;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mClock = new TextView(this);
        setContentView(mClock);
    }

    private Handler mHandler = new Handler();
    private Runnable timerTask = new Runnable() {
        @Override
        public void run() {
            Calendar now = Calendar.getInstance();
            mClock.setText(String.format("%02d:%02d:%02d",
                    now.get(Calendar.HOUR),
                    now.get(Calendar.MINUTE),
                    now.get(Calendar.SECOND)) );
            mHandler.postDelayed(timerTask,1000);
        }
    };

    @Override
    public void onResume() {
        super.onResume();
        mHandler.post(timerTask);
    }

    @Override
    public void onPause() {
        super.onPause();
        mHandler.removeCallbacks(timerTask);
    }
}