String fnm = "cat"; //  this is image file name
String PACKAGE_NAME = getApplicationContext().getPackageName();
int imgId = getResources().getIdentifier(PACKAGE_NAME+":drawable/"+fnm , null, null);
System.out.println("IMG ID :: "+imgId);
System.out.println("PACKAGE_NAME :: "+PACKAGE_NAME);
//    Bitmap bitmap = BitmapFactory.decodeResource(getResources(),imgId);
your_image_view.setImageBitmap(BitmapFactory.decodeResource(getResources(),imgId));