how to identify the empty xml tag using statx parser

Question

I want to idendify the tag while parsing this XML content. we have method like isStartElement() or isEndElement(). but this is not comes under both category. pls help me. how to address this kind of tags.

Code :

 import java.io.StringReader;
 import java.util.Hashtable;
 import java.util.Iterator;

 import javax.xml.stream.Location;
 import javax.xml.stream.XMLEventReader;
 import javax.xml.stream.XMLInputFactory;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.events.EndElement;
 import javax.xml.stream.events.StartElement;
 import javax.xml.stream.events.XMLEvent;

 public class Sample {

public static void main(String[] args) {
    String xPath = "HAI/ONE";       
    String xml = "<HAI><ONE/></HAI>";
    try {
        System.out.println(getValueByXPath(xml,xPath));

    } catch (Exception e) {
        e.printStackTrace();
    }




}     
 public  String getValueByXPath(String xmlString, String xPathString){
    String value = "";
    String tagName = null;
    int index = 2;
    int hashIndex = 1;
    int tagBalance = 0;
    String tagIndex = null;
    String[] tagIndexArr = null;
    Hashtable<Integer,String> xPathHashtable = null;

    XMLInputFactory xmlInputFactory;
    XMLEventReader xmlEventReader;
    try{            
        xmlInputFactory = XMLInputFactory.newInstance();
        xmlInputFactory.setProperty  
          (XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES,Boolean.TRUE);       
        xmlInputFactory.setProperty
          (XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES,Boolean.FALSE);
        xmlInputFactory.setProperty(XMLInputFactory.IS_COALESCING, 
           Boolean.FALSE);   
        xmlEventReader = xmlInputFactory.createXMLEventReader(new StringReader
           (xmlString));

        //Split XPath 
        xPathHashtable = splitXPath(xPathString);

        tagIndex = xPathHashtable.get(hashIndex);
        tagIndexArr = tagIndex.split("=");
        tagName = tagIndexArr[0];
        index = Integer.parseInt(tagIndexArr[1])+1;

        while (xmlEventReader.hasNext()) { 
            XMLEvent e = xmlEventReader.nextEvent(); 

            if(tagBalance < 0 ){
                return "";
            }

            if(index==1 && e.isCharacters()){
                value = e.asCharacters().getData();
                hashIndex++;
                tagIndex = xPathHashtable.get(hashIndex);
                if(tagIndex == null)break;
                tagIndexArr = tagIndex.split("=");
                tagName = tagIndexArr[0];
                index = Integer.parseInt(tagIndexArr[1])+1;
                tagBalance = 0;
                System.out.println(tagName+"tag"+index);

            }
            if (e.isStartElement()) {                   
                StartElement startElement = e.asStartElement(); 
                if(tagName.equalsIgnoreCase(startElement.getName
                                                  ().getLocalPart())){
                    index--;
                    tagBalance++;
                }
            }   

            if (e.isEndElement()) { 

                EndElement endElement = e.asEndElement();

                if(tagName.equalsIgnoreCase(endElement.getName
                                                 ().getLocalPart())){                       
                    tagBalance--;
                                        }
            }
        }

    }catch(Exception e){
        e.printStackTrace();
    }
    return value;
}

public  Hashtable<Integer,String> splitXPath(String xPath){

    Hashtable<Integer,String> xPathHashtable = null;
    String[] xPathSplit = null;
    int hashIndex = 0;

    int index = 1;
    String tag= null;
    try{
        xPathHashtable = new Hashtable<Integer,String>();
        xPathSplit = xPath.split("[\\[\\]/]");

        for(int i=0;i<xPathSplit.length;i++){

            if(xPathSplit[i].isEmpty()) continue;

            try{
                index = Integer.parseInt(xPathSplit[i]);
            }catch(Exception e){
                tag = xPathSplit[i];
                index = 1;
                hashIndex++;
            }
            xPathHashtable.put(hashIndex, tag+"="+index);               
        }

    }catch(Exception e){
        e.printStackTrace();
    }

    return xPathHashtable;
}
 }

I am simulating XPath scenario with Stax parser.

Answer 1

I have had the same issue as you and couldn't find a solution anywhere.

What you want to do is use

xmlEventReader.peek().isEndElement()  

and handle however you'd like to. peek() doesn't move the element like .nextEvent() does.