code: public Document parse(String uri)
          throws SAXException, IOException {
          if (uri == null) {
              throw new IllegalArgumentException("URI cannot be null");
          }
  
          InputSource in = new InputSource(uri);
          return parse(in);
      }
docs: Parse the content of the given URI as an XML document
  and return a new DOM {@link Document} object.
  An <code>IllegalArgumentException</code> is thrown if the
  URI is <code>null</code> null.
  
  @param uri The location of the content to be parsed.
  @return A new DOM Document object.
  @exception IOException If any IO errors occur.
  @exception SAXException If any parse errors occur.
  @see org.xml.sax.DocumentHandler