Helper class to download an image from a specified URL

BitmapHelper.java

public class BitmapHelper {
	
	class DownloadImageFromURL extends AsyncTask<String, String, Bitmap> {
		
		private final WeakReference<ImageView> imageViewReference;
		String mUrl;
		private int mWidth = 0;
		private int mHeigth = 0;

		private boolean isThumbnail = false;
		
		public DownloadImageFromURL (String url, ImageView imageview) {
			mUrl = url;
			imageViewReference = new WeakReference<ImageView>(imageview);
		}
		
		public DownloadImageFromURL (String url, ImageView imageview, int rWidth, int rHeight) {
			mUrl = url;
			imageViewReference = new WeakReference<ImageView>(imageview);
			isThumbnail = true;
			mWidth = rWidth;
			mHeigth = rHeight;
		}
		
			
		@Override
		protected Bitmap doInBackground(String... params) {
			if (isThumbnail) {
				return DownloadImageFromUrl(mUrl, mWidth, mHeigth);
			}
			return DownloadImageFromUrl(mUrl);
		}
		
		@Override
		protected void onPostExecute(Bitmap bitmap) {
			if(isCancelled()) {
				bitmap = null;
			}
			
			if (imageViewReference != null) {
			    ImageView imageView = imageViewReference.get();
			    DownloadImageFromURL bitmapDownloaderTask = getDownloaderTask(imageView);
			    if (this == bitmapDownloaderTask) {
			        imageView.setImageBitmap(bitmap);
			    }
			}
		}
			
	}
	
	private static DownloadImageFromURL getDownloaderTask(ImageView imageView) {
	    if (imageView != null) {
	        Drawable drawable = imageView.getDrawable();
	        if (drawable instanceof DownloadedDrawable) {
	            DownloadedDrawable downloadedDrawable = (DownloadedDrawable)drawable;
	            return downloadedDrawable.getTask();
	        }
	    }
	    return null;
	}
	
	static class DownloadedDrawable extends ColorDrawable {
	    private final WeakReference<DownloadImageFromURL> taskReference;

	    public DownloadedDrawable(DownloadImageFromURL task) {
	        super(Color.BLACK);
	        taskReference =
	            new WeakReference<DownloadImageFromURL>(task);
	    }

	    public DownloadImageFromURL getTask() {
	        return taskReference.get();
	    }
	}
	
	private static boolean cancelPotentialDownload(String url, ImageView imageView) {
	    DownloadImageFromURL downloaderTask = getDownloaderTask(imageView);

	    if (downloaderTask != null) {
	        String bitmapUrl = downloaderTask.mUrl;
	        if ((bitmapUrl == null) || (!bitmapUrl.equals(url))) {
	        	downloaderTask.cancel(true);
	        } else {
	            return false;
	        }
	    }
	    return true;
	}
	
	public void download(String url, ImageView imageView, boolean thumbnail) {
	     if (cancelPotentialDownload(url, imageView)) {
	    	 DownloadImageFromURL task;
	    	 if (thumbnail) {
	    		 task = new DownloadImageFromURL(url, imageView, 48, 48);
	    	 }
	    	 else {
	    		 task = new DownloadImageFromURL(url, imageView);
	    	 }
	         DownloadedDrawable downloadedDrawable = new DownloadedDrawable(task);
	         imageView.setImageDrawable(downloadedDrawable);
	         task.execute();
	     }
	}
	
	public int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
	    final int height = options.outHeight;
	    final int width = options.outWidth;
	    int inSampleSize = 1;

	    if (height > reqHeight || width > reqWidth) {
	        if (width > height) {
	            inSampleSize = Math.round((float)height / (float)reqHeight);
	        } else {
	            inSampleSize = Math.round((float)width / (float)reqWidth);
	        }
	    }
	    return inSampleSize;
	}
	
	public Bitmap decodeSampledBitmapFromResource(byte [] data, int reqWidth, int reqHeight) {

	    final BitmapFactory.Options options = new BitmapFactory.Options();
	    options.inJustDecodeBounds = true;
	    BitmapFactory.decodeByteArray(data, 0, data.length, options);

	    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

	    options.inJustDecodeBounds = false;
	    return BitmapFactory.decodeByteArray(data, 0, data.length, options);
	}
	
	public Bitmap DownloadImageFromUrl (String url, int width, int height) {
		
		Bitmap bitmap = null;
		HttpUriRequest request;
		HttpClient httpClient;
		HttpResponse response;
		StatusLine statusLine = null;
		int statusCode = 0;
		
		try {
			
			request = new HttpGet(url.toString());
		    httpClient = new DefaultHttpClient();
		    response = httpClient.execute(request);

		    statusLine = response.getStatusLine();
		    statusCode = statusLine.getStatusCode();
		    
		    if (statusCode == 200) {
		      HttpEntity entity = response.getEntity();
		      byte[] bytes = EntityUtils.toByteArray(entity);
		      bitmap = decodeSampledBitmapFromResource(bytes, width, height);		
		    }
		}
		    catch (Exception e) {
		    	Log.v(Constants.TAG, ("Download failed, HTTP response code " + statusCode + " - " + statusLine.getReasonPhrase()));
		}
		return bitmap;	
	}
	
	public Bitmap DownloadImageFromUrl (String url) {
		Bitmap bitmap = null;
		HttpUriRequest request;
		HttpClient httpClient;
		HttpResponse response;
		StatusLine statusLine = null;
		int statusCode = 0;
		
		try {
			
			request = new HttpGet(url.toString());
		    httpClient = new DefaultHttpClient();
		    response = httpClient.execute(request);

		    statusLine = response.getStatusLine();
		    statusCode = statusLine.getStatusCode();
		    
		    if (statusCode == 200) {
		      HttpEntity entity = response.getEntity();
		      byte[] bytes = EntityUtils.toByteArray(entity);
		      bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);		
		    }
		}
		    catch (Exception e) {
		    	Log.v(Constants.TAG, ("Download failed, HTTP response code " + statusCode + " - " + statusLine.getReasonPhrase()));
		}
		return bitmap;	
	}

}