Extracting Meta Tags

[Frank Apap]

Hi,

I'm trying to extract meta tags from webpages.  I'm using the code below
but am finding that only a small subset of meta tags are being returned.
There are meta tags like those for facebook open graph that i am interested
in that are not being returned?

public static void extractMetaFromUrl(String url) throws Exception{

  Any23 runner = new Any23();

  runner.setHTTPUserAgent("test-user-agent");

  HTTPClient httpClient = runner.getHTTPClient();

  DocumentSource source = new HTTPDocumentSource(

        httpClient,

        url

      );

  ByteArrayOutputStream out = new ByteArrayOutputStream();

  TripleHandler handler = new JSONWriter(out);

      try {

      //runner.extract(source, handler);

      final ExtractionParameters extractionParameters =
ExtractionParameters.newDefault();

        extractionParameters.setFlag("any23.extraction.head.meta", true);

      SingleDocumentExtraction sde = new SingleDocumentExtraction(source,

      new HTMLMetaExtractorFactory(),handler);

      SingleDocumentExtractionReport rpt = sde.run(extractionParameters);

      //System.out.println(rpt.toString());

      } finally {

      handler.close();

      }

      String n3 = out.toString("UTF-8");

      System.out.println(n3);

}