code: @Override
    public URL getURL() throws IOException {
      URL url = this.servletContext.getResource(this.path);
      if (url == null) { throw new FileNotFoundException(getDescription()
          + " cannot be resolved to URL because it does not exist"); }
      return url;
    }
docs: This implementation delegates to <code>ServletContext.getResource</code>,
  but throws a FileNotFoundException if no resource found.
  
  @see javax.servlet.ServletContext#getResource(String)