How to set imageview resource from variable?

I have a lot of images (hundreds) and I need to put some of them as a resource of ImageView, but if I would create If Then set Image to Image name, I die from these tons of code. I want to set Image resource which name is inside a variable, but I can't find out how. If I have img.setImageResource(R.drawable.my_image); How can I assign variable name at my_image instead of true image name? Please help. Thanks.

Try this:

 String resourceName = "clouds";
 int resourceIdentifier = getResources().getIdentifier(resourceName, "drawable", Constants.CURRENT_CONTEXT.getPackageName());

Then

imgView.setImageResource(resourceIdentifier);