code: public static File getRelativePathTo(final File parent, final String separator,
  		final String folders, final String filename)
  	{
  		final List<String> list = new ArrayList<>(Arrays.asList(folders.split(separator)));
  		if (filename != null && !filename.isEmpty())
  		{
  			list.add(filename);
  		}
  		return getRelativePathTo(parent, list);
  	}
docs: Gets the file or directory from the given parent File object and the relative path given over
  the list as String objects.
  
  @param parent
  The parent directory.
  @param separator
  The separator for separate the String folders.
  @param folders
  The relative path as a String object separated with the defined separator.
  @param filename
  The filename.
  @return the resulted file or directory from the given arguments.