download and cache menu icons

icon.java

			//Download menu icons
			if (menu != null && !menuImageURL.equals("")) {
				
				File cacheDir = new File (ClassificationActivity.this.getCacheDir(), "/ic_menu/");
				if (!cacheDir.exists()) cacheDir.mkdirs();
				List<String> existingFiles = Arrays.asList(cacheDir.list());
				for (int i = 0; i < menu.length(); i++) {
					try {
						String filename = menu.getJSONObject(i).getString("image");
						
						if (!existingFiles.contains(filename)) {
							try {
								File file = new File(cacheDir, filename);
								/* Open a connection to that URL. */
								URL	url = new URL(menuImageURL + filename);
		                        URLConnection ucon = url.openConnection();
		 
		                        /*
		                         * Define InputStreams to read from the URLConnection.
		                         */
		                        InputStream is = ucon.getInputStream();
		                        BufferedInputStream bis = new BufferedInputStream(is);
		 
		                        /*
		                         * Read bytes to the Buffer until there is nothing more to read(-1).
		                         */
		                        ByteArrayBuffer baf = new ByteArrayBuffer(50);
		                        int current = 0;
		                        while ((current = bis.read()) != -1) {
		                                baf.append((byte) current);
		                        }
		 
		                        /* Convert the Bytes read to a String. */
		                        FileOutputStream fos = new FileOutputStream(file);
		                        fos.write(baf.toByteArray());
		                        fos.close();
							} catch (MalformedURLException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							} catch (IOException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						} else {
							existingFiles.remove(filename);
						}
						
					} catch (JSONException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					
				}
				for (String string : existingFiles) {
					File image = new File(cacheDir, string);
					image.delete();
				}
			}