code: public static void checkCopyToOK(Resource source, Resource target) throws IOException {
  	if (!source.isFile()) {
  	    if (source.isDirectory()) throw new IOException("can't copy [" + source.getPath() + "] to [" + target.getPath() + "], source is a directory");
  	    throw new IOException("can't copy [" + source.getPath() + "] to [" + target.getPath() + "], source file does not exist");
  	}
  	else if (target.isDirectory()) {
  	    throw new IOException("can't copy [" + source.getPath() + "] to [" + target.getPath() + "], target is a directory");
  	}
      }
docs: check if copying a file is ok with the rules for the Resource interface, to not change this
  rules.
  
  @param source
  @param target
  @throws IOException