code: public InputStream getInputStream() throws IOException {
      InputStream is = this.servletContext.getResourceAsStream(this.path);
      if (is == null) { throw new FileNotFoundException("Could not open " + getDescription()); }
      return is;
    }
docs: This implementation delegates to <code>ServletContext.getResourceAsStream</code>,
  but throws a FileNotFoundException if no resource found.
  
  @see javax.servlet.ServletContext#getResourceAsStream(String)