XPath Select Attribute Values from Parent AND Child Nodes

Following is my XML File:

<?xml version="1.0" encoding="UTF-8"?>
   <query xmlns:yahoo="http://ift.tt/1apoFAW" yahoo:lang="en-GB">
      <results>

        <sector sectorid="1" sectorname="Basic Materials">
          <industry id="112" name="Agricultural Chemicals"/>
          <industry id="132" name="Aluminum"/>
          <industry id="110" name="Chemicals - Major Diversified"/>
          <industry id="131" name="Copper"/>
          <industry id="134" name="Gold"/>
          <industry id="121" name="Independent Oil and Gas"/>
          <industry id="120" name="Major Integrated Oil and Gas"/>
        </sector>

     </results>
   </query>

From the above XML file, I am looking to store the values of attributes: sectorid, id, and name in the appropriate variables (I'm using Java). I have been looking at different XPath expressions and I came up with the following code, however, a java.lang.NumberFormatException: For input string: "" exception is thrown when storing the value of id attribute. Here's my code:

public class XMLToDatabase {

    private static int __SectorID;
    private static int __IndustryID;
    private static String __IndustryName;

    public static void main(String[] args) throws SQLException, UnsupportedEncodingException, ParserConfigurationException, SAXException, IOException, XPathExpressionException {

        try {               
            File _XMLFile = new File("SectorsAndIndustries.xml");

            DocumentBuilderFactory _DocumentBuilderFactory = DocumentBuilderFactory.newInstance();
            _DocumentBuilderFactory.setNamespaceAware(true);

            DocumentBuilder _DocumentBuilder = _DocumentBuilderFactory.newDocumentBuilder();
            Document _Document = _DocumentBuilder.parse(_XMLFile);  

            _Document.getDocumentElement().normalize();

            XPath _XPath = XPathFactory.newInstance().newXPath();

            XPathExpression _XPathExpression = _XPath.compile("//sector | //industry");

            NodeList _NodeList = (NodeList) _XPathExpression.evaluate(_Document, XPathConstants.NODESET);


            for (int i = 0; i < _NodeList.getLength(); i++) {
                Node _Node = _NodeList.item(i);

                if(_Node.getNodeType() == Node.ELEMENT_NODE) {
                    Element _Element = (Element) _Node;

                    __SectorID = Integer.parseInt(_Element.getAttribute("sectorid"));
                    __IndustryID = Integer.parseInt(_Element.getAttribute("id"));
                    __IndustryName = _Element.getAttribute("name");
                }

            System.out.println(__SectorID + ", " + __IndustryID + ", " + __IndustryName);
            }
        } catch (Exception e) {
        e.printStackTrace();
        }

    }

}

Could someone please help me determine if it is the XPath Expression that I am making a mistake with, or if is the way I am storing the second variable __IndustryID? Because the first variable __SectorID correctly stores the value 1, but throws the above mentioned exception for __IndustryID. Ideally, I would want to store the values of all 3 attributes every time the for loop is executed, to save them to a database table. Please let me know if any more information is required.