Need help in JAVA UDF

Hi Experts,

I have a requirement where i need to do a lookup call to a web service and need to capture a value from the response message.I am using the below code t call a web service and able to get the response. but need help in retrieving the output value.

Requirement -

Response message looks like below -

<Lists xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

<Items>

<List>

<ID>gWmoJWo4UtuyqBIx101Gg$pdxyhgLZLzjYDA</ID>

<Name123</Name></List>

<List>

<ID>gWmoJWo4UtuypqV5oxmVyewtAPMVARXHnmg</ID>

<Name>456</Name>

</List>

.

.

.

.

.

.

.</Items>

</Lists>

I will many number of List nodes in the resposne message and need to get ID as the output value where the Name field = 456(which will be one).

I am using the below code -

AbstractTrace trace = container.getTrace();

String ID =""; 

try

  {

/* Determine a channel (Business system, Communication channel) */

  Channel channel = LookupService.getChannel("BC_Middleware","PI_Receiver");

/* Get an accessor for the soap channel */

  SystemAccessor accessor = null;

  accessor = LookupService.getSystemAccessor(channel);

/* Construct the REST Request Message*/

  String loginxml ="<?xml version=\"1.0\" encoding=\"UTF-8\"?><ns0:definitionId>definitionId</ns0:definitionId>";

InputStream inputStream = new ByteArrayInputStream(loginxml.getBytes());

/*  Create xml payload */

  Payload payload = LookupService.getXmlPayload(inputStream);

/* Execute lookup.*/

  Payload RESTOutPayload = null;

  RESTOutPayload = accessor.call(payload);  /*The SOAP call is made here and the response obtained is in the RESTOutPayload.*/

/* Parse the Payload to get the REST Response back.*/

  InputStream inp = RESTOutPayload.getContent();

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

  DocumentBuilder builder = factory.newDocumentBuilder();

  Document document = builder.parse(inp);

  XPathExpression expr = xpath.compile("//Lists/Items/List[Name = '456']");

  NodeList List = (NodeList) expr.evaluate(document, XPathConstants.NODESET);

  if (List.getLength() == 0 ){ // If no such Custom Field is found

  result.addValue("") ; // Blank value is added to the output

  }

  else{ // If  the desired Custom Field is found

     Node listnode = List.item(0); // index is 0 since there is only one value available under this node and no looping needed

     String ID = listnode.getFirstChild().getNodeValue() ; //Value is fetched here

     result.addValue(ID) ; // fetched value i added to the output.

     }

  }

  catch (Exception e)

  {     

  trace.addWarning("Error" + e); 

  }

I am not able to execute the UDF its giving error - cannot find symbol xpath. and i added all the libraries (org.w3c.domain, javax.xml.xpath.*)

Please help me on this

Thanks & regards

narayanareddy B