Parsing Apache Tika XML Output returns Unknown Tag

Question

Basically, i parse several xml output from Apache Tika to get metadata (via meta tags) and list of embedded files using <div class="embedded" id="content">. However, i found my map had several key Unknown tag (0x...). I wonder if it caused by Tika's incomplete tag output because the error i get only related to unclosed tag - which i suspect within the body of XML instead of the output i want (meta, div). However, it is rather illogical where the only code that writes into the map are meta tags and divs (with embedded class) - which is only a small part of the document.

public class Parse {
    private class internalXMLReader extends DefaultHandler{
        public final Map<String, Object> entityList = new HashMap<>();

        @Override
        public void startElement(String uri, String localname, String qName, Attributes attributes) throws SAXException{
            String key, content;
            if(qName.equalsIgnoreCase("meta")){
                key = attributes.getValue("name");
                content = attributes.getValue("content");
                if(key.contains("Content-Type")){
                    String tmp[] = attributes.getValue("content").replace(' ', '\0').split(";");
                    if(tmp.length > 1){
                        content = tmp[0];
                    }
                }
                entityList.put(key, content);
            }
            else if(qName.equalsIgnoreCase("div")){
                if((attributes.getValue("class") != null) && (attributes.getValue("class").equalsIgnoreCase("embedded"))){
                    key = "embedded";
                    List<String> inlist;
                    if(entityList.containsKey("embedded") && (entityList.get("embedded") instanceof List)){
                        inlist = (List) entityList.get(key);
                    }
                    else{
                        inlist = new LinkedList<>();
                        entityList.put(key, inlist);
                    }
                    inlist.add(attributes.getValue("id"));
                }
            }
        }

        @Override
        public void endElement(String uri, String localname, String qName) throws SAXException{
            //no, i just did not want to validate or such..
        }

        @Override
        public void characters(char ch[], int start, int length) throws SAXException{
            //no, we don't actually read <something>this</something> yet
        }
    }
    public Entity parse(String xml, Entity in){
        try{
            InputSource xmlinput = new InputSource(new StringReader(xml));
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser parser = factory.newSAXParser();
            internalXMLReader handler = new internalXMLReader();
            parser.parse(xmlinput, handler);
            in.addMeta(handler.entityList);
        }
        catch(IOException | ParserConfigurationException | SAXException ex){
            Logger.getLogger(TikaParseNCluste.class.getName()).log(Level.SEVERE, null, ex);
        }
        return in;
    }
}

Perhaps i should take a look at my 800+ xml files.

Answer 1

Google and javadocs had no information regarding this thing and i'm rather impatient. However runs grep -i -l -r "name=\"unknown" . i got several jpg files had <meta name="Unknown..." contents="..."/> perhaps this is why. I don't expect ApacheTika would give such outputs. So, i changed my code to:

...
if(qName.equalsIgnoreCase("meta") && (attributes.getValue("name") != null)){
                key = attributes.getValue("name");
                if((key != null) && (!key.contains("Unknown"))){
                    content = attributes.getValue("content");
                    if(key.contains("Content-Type")){
                        String tmp[] = attributes.getValue("content").replace(' ', '\0').split(";");
                        if(tmp.length > 1){
                            content = tmp[0];
                        }
                    }
                    entityList.put(key, content);
                }
            }
...

I wonder if it's a bug or something else. So far, quick query to Google Search with keyword apache tika unknown tag only lead me here.