xpaths not working in java

Question

I am trying to access a url, get the html from it and use xpaths to get certain values from it. I am getting the html just fine and Jtidy seems to be cleaning it appropriately. However, when I try to get the desired values using xpaths, I get an empty NodeList back. I know my xpath expression is correct; I have tested it in other ways. Whats wrong with this code. Thanks for the help.

String url_string = base_url + countries[c];
URL url = new URL(url_string);

Tidy tidy = new Tidy();
tidy.setShowWarnings(false);
tidy.setXHTML(true);
tidy.setMakeClean(true);
Document doc = tidy.parseDOM(url.openStream(), null);
//tidy.pprint(doc, System.out);

String xpath_string = "id('catlisting')//a";
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile(xpath_string);

NodeList nodes = (NodeList)expr.evaluate(doc, XPathConstants.NODESET);
System.out.println("size="+nodes.getLength());
for (int r=0; r<nodes.getLength(); r++) {
    System.out.println(nodes.item(r).getNodeValue()); 
}

Answer 1

Try "//div[@id='catlisting']//a"