I have to parse this XML https://i.stack.imgur.com/YrIzS.jpg to extract the highlighted string under the "DetailPageURL" tag. I did a try but have quite confused ideas. I'm working on Android SDK
import android.os.AsyncTask;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
public class ReflinkFetcher extends AsyncTask<String, Void, String> {
String refLink = null;
@Override
protected String doInBackground( String... url){
Document doc = openXML(url[0]);
Element rootElement = doc.getDocumentElement();
refLink = getString("DetailPageUrl", rootElement);
return refLink;
}
public String getRefLink(){
return refLink;
}
private Document openXML(String url) {
Document doc = null;
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.parse(new URL(url).openStream());
} catch (SAXException e1) {
e1.printStackTrace();
} catch (ParserConfigurationException e1) {
e1.printStackTrace();
} catch (MalformedURLException e2) {
e2.printStackTrace();
} catch (IOException e3) {
e3.printStackTrace();
}
return doc;
}
private String getString(String tagName, Element element) {
NodeList list = element.getElementsByTagName("Items");
if (list != null && list.getLength() > 0) {
NodeList subList = list.item(0).getChildNodes(); //0=items
if (subList != null && subList.getLength() > 0) {
subList = subList.item(4).getChildNodes(); //4=item
if( subList != null && subList.getLength() >0 ) {
subList = subList.item(2).getChildNodes(); //2=DetailPageURL
if( subList != null && subList.getLength() >0 ) {
return subList.item(0).getNodeValue(); // Value??
}
}
}
}
return null;
}
}
The final return null is being executed. I think the "getString" method is quite poor too. How can I improve it?