code: public String getRootPath(){
  		if(this.isValid() && this.setRootPath!=null){
  			return StringUtils.substringBefore(this.getAbsolutePath(), this.setRootPath);
  		}
  		return null;
  	}
docs: Returns the root path which is either the absolute path or (if any directory is set and {@link #getSetRootPath()} returns not null) the path to the set-as-root path
  @return absolute or prefix path for the set-as-root path if the file info object is valid and a relative path was given to a constructor as directory, null otherwise