private int _nVersionCode = 0;	
private boolean _bNewVersion = false;


// onCreate
     	 _nVersionCode   = this.getPackageManager()
     	.getPackageInfo(this.getPackageName(), 0).versionCode;
     	Log.d(String.valueOf(_nVersionCode), "versionCode");

// onStart loadPreferences
 public void loadPreferences() {
			//SharedPreferences settings = getSharedPreferences(F.PREFERENCES_NAME, 0);
			SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
		int nOldVersionCode =	settings.getInt("_nVersionCode",  0);// old vesion
		if(_nVersionCode > nOldVersionCode)
			_bNewVersion = true;
	}

// onDestroy savePreferences	
	public void savePreferences() {
			SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
			SharedPreferences.Editor editor = settings.edit();
			editor.putInt("_nVersionCode", _nVersionCode); // save current version code
			editor.commit();
	}

try {
		String MYFILE = "my_file";
		String strText = "My text";

                // MODE_APPEND, MODE_WORLD_READABLE, MODE_WORLD_WRITEABLE
		// create new file or rewrite existing
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_PRIVATE);
                // append to file
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_APPEND);

		fos.write(strText.getBytes());
		fos.close();					
	} catch (IOException e) {
		e.toString();
    }	

try {
// new file    
BufferedWriter out = new BufferedWriter(
    		new FileWriter("outfilename"));
    // append text 
   BufferedWriter out = new BufferedWriter(new FileWriter("outfilename", true));
    out.write("some text");
    out.close();
 } catch (IOException e) {
   e.toString();
}			

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
			int quality) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		src.compress(format, quality, os);

		byte[] array = os.toByteArray();
		return BitmapFactory.decodeByteArray(array, 0, array.length);
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GRAY);
            
                        //  you need to insert some image flower_blue into res/drawable folder
			Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.flower_blue);
                        // Best of quality is 80 and more, 3 is very low quality of image 
			Bitmap bJPGcompress = codec(b, Bitmap.CompressFormat.JPEG, 3);
                   // get dimension of bitmap getHeight()  getWidth()
		   int h = b.getHeight();
           
           canvas.drawBitmap(b, 10,10, paint);
           canvas.drawBitmap(bJPGcompress, 10,10 + h + 10, paint);
           
		}

	}
}

    

        14 // error

        "18" // ok