How to retrieve XML element attribute having namespaces using java?

I have the below xml and I am trying to retrieve the value of id under BoostBuryDimensionValue tag using the java code but returns nothing. Can some one help me on this. Thanks in advance.

Input XML

 <?xml version="1.0" encoding="UTF-8"?>
<ContentItem type="OrganicZoneContent" xmlns="http://ift.tt/1LDy0Hm" >
  <TemplateId>OrganicResults</TemplateId>
  <Name>OrganicResults</Name>
  <Property name="navigation_records">
    <BoostBury rollupKey="grp_id" recspecField="grp_id" xmlns="http://ift.tt/1Bcusux">

      <BoostBuryRecords>
        <BoostBuryRecord recordType="CRITERIA" boostBuryType="BOOST">
          <BoostBurySearch terms="null" key="null"/>
          <BoostBuryDimensionValues>
            <BoostBuryDimensionValue id="4294965238" name="career" dimensionName="Occasion"/>
          </BoostBuryDimensionValues>
        </BoostBuryRecord>

      </BoostBuryRecords>
     </BoostBury>
  </Property>
</ContentItem>

and the java code i am using is

public static void main(String[] args) throws Exception { 
    InputStream xml = new FileInputStream("tempinput.xml");
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder(); 
    Document doc = db.parse(xml); 
    XPath xpath = XPathFactory.newInstance().newXPath(); 
    XPathExpression expr = xpath.compile("ContentItem/Property[@name='navigation_records']/BoostBury/BoostBuryRecords/BoostBuryRecord/@id");
    Object result = expr.evaluate(doc, XPathConstants.STRING); 
    System.out.println("BoostBuryDimensionValue id = " + result);

}