process Xquery with saxon9

I'm new with saxon9- and i want to processing a Xquery against a XML, i use this XML

<catalog>
  <cd>
   <title>Empire Burlesque</title>
   <artist>Bob Dylan</artist>
   <country>USA</country>
   <company>Columbia Records</company>
   <price>10.90</price><year>1985</year>
  </cd>
  <cd>
   <title>Hide Your Heart</title>
   <artist>Bonnie Tyler</artist>
   <country>UK</country>
   <company>CBS Records</company>
   <price>9.90</price><year>1988</year>
  </cd>
  <cd>
   <title>Best of Enya</title>
   <artist>Enya</artist>
   <country>UK</country>
   <company>ABC Records</company>
   <price>9.90</price>
   <year>1995</year>
  </cd>
</catalog>

I want to execute any Xquery against this xml, i have seen in saxon9api but i don't understand somethings, i find this code in saxon9 but i dont understand it

public void runXquery(String file, String expresion) throws SaxonApiException{
    Processor proc = new Processor(false);
    XQueryCompiler comp = proc.newXQueryCompiler();
    comp.declareNamespace("xsd", "http://ift.tt/tphNwY");
    XQueryExecutable exp = comp.compile("<catalog>{//ITEM[1]}</catalog>");
    XQueryEvaluator qe = exp.load();

    File inputFile = new File("xmlToHtml/catalog.xml");
    FileInputStream fis;
    try {
        fis = new FileInputStream(inputFile);
    } catch (FileNotFoundException e) {
        throw new SaxonApiException(
                "Input file not found. The current directory should be the Saxon samples directory");
    }
    SAXSource source = new SAXSource(new InputSource(fis));
    source.setSystemId(inputFile.toURI().toString());

    qe.setSource(source);

    ContentHandler ch = new XMLFilterImpl() {

        public void startElement(String uri, String localName, String qName) throws SAXException {
            System.out.println("start element {" + uri + "}" + localName);
        }

        public void endElement(String uri, String localName, String qName) throws SAXException {
            System.out.println("End element {" + uri + "}" + localName);
        }

    };
    qe.run(new SAXDestination(ch));


}