Parsing XML tagnames in Java from a URL

Question

I am trying to retrieve content from xml tagnames from a url, but my int numberOfDetails has a length of 0. What am I doing wrong?

//Edited Code

public String[] dumpTitles(String[] xmlFiles) {


        String[] elementsArray = null;
        try { 
            URL xmlContent = new URL("http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml");
            DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document doc = db.parse(new InputSource(xmlContent.openStream()));


            Toast.makeText(this, "xml file: " + xmlContent, 1000).show();

            NodeList detailsNodeList = doc.getElementsByTagName("Details");
            int numberOfDetails = detailsNodeList.getLength();
            String str = String.format("There are %d Details elements", numberOfDetails);
            Log.println(Log.DEBUG, TAG, str);
            Toast.makeText(this, "number of details: " + str, 1000).show();
            elementsArray = getElementByTagName("ProductName", numberOfDetails, detailsNodeList);
        }
        catch (Exception ex) {
            Log.println(Log.DEBUG, TAG, "XML Parsing failed: " + ex.getMessage());
        }

        return elementsArray;  

    }

  public String[] getElementByTagName(String detailTagName, int numberOfDetails, NodeList detailsNodeList) throws Exception {
      String[] elementsArray = null;
      ArrayList<String> elementsArrayList = new ArrayList<String>();
      Toast.makeText(this, "TEST2", 1000).show();
        for (int k = 0; k < numberOfDetails; k++) {
            Toast.makeText(this, "TEST3", 1000).show();
            Element nDetails = (Element)detailsNodeList.item(k);
            NodeList elementNodeList = ((Document) nDetails).getElementsByTagName(detailTagName);
            Node nodeName = elementNodeList.item(k);
            String nodeString = String.format("%s", nodeName);
            elementsArrayList.add(nodeString);
            elementsArray = elementsArrayList.toArray(elementsArray);
            Log.println(Log.DEBUG, TAG, nodeString);
            Toast.makeText(this, "TEST4", 1000).show();
            Toast.makeText(this, "ELEMENT" + elementsArray[0], 1000).show();

        }

        return elementsArray;
}

// Original Code String xmlContent = "http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml"; Log.println(Log.DEBUG, TAG, "FILE NAME: " + xmlContent); String[] elementsArray = null; try { DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder(); Toast.makeText(this, "xml file: " + xmlContent, 1000).show(); Document doc = db.parse(new InputSource(new StringReader(xmlContent))); NodeList detailsNodeList = doc.getElementsByTagName("Details"); int numberOfDetails = detailsNodeList.getLength();

Answer 1

You shouldn't use StringReader to read from url. StringReader reads string you passed in constructor, it doesn't download file from the web. You can use URL class instead:

URL xmlContent = new URL("http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml");
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = db.parse(new InputSource(xmlContent.openStream()));

Another way:

You can use constructor of InputSource which takes String :

String pathToDocument = "http://webdev4.matcmadison.edu/mab/AmazonXML/georgeEliot.xml";
Document doc = db.parse(new InputSource(pathToDocument));