[xsl] How to select nodes with explicitly set default namespace - DOM4J

["Barbara Worwood" <bworwood@xxxxxxxxxxxxx>]

Hi,

I am having a problem selecting nodes that are part of a default namespace. 
The xml format cannot be modified as it is part of an NHS UK standard.

For Example:  xmlns=="urn:hl7-org:v3"  is the default namespace, though a 
call to selectSingleNode from the root element will not return anything for 
me. See code below...

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<?xml version="1.0" encoding="UTF-8" ?>
<!-- The element below is the content of the first payload container -->
<PRSC_IN080000UK06 xmlns="urn:hl7-org:v3" 
xmlns:fo="http://www.w3.org/1999/XSL/Format"; 
xmlns:voc="urn:hl7-org:v3/voc"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xsi:schemaLocation="urn:hl7-org:v3../Schemas/PRSC_IN080000UK06.xsd">
<id root="A6C66142-1DD1-11B2-9062-8F5E91AA2DD7"/>
<creationTime value="20040913030014" />
<versionCode code="V3NPfIT2.0" />
<interactionId root="2.16.840.1.113883.2.1.3.2.4.12" 
extension="PRSC_IN080000UK06" />
<processingCode code="P" />
<processingModeCode code="T" />
<acceptAckCode code="NE" />
<communicationFunctionRcv>
<device>
<id root="2.16.840.1.113883.2.1.3.2.4.10" extension="RJR-0000217" />
</device>
</communicationFunctionRcv>
<communicationFunctionSnd>
<device>
<id root="2.16.840.1.113883.2.1.3.2.4.10" extension="T141A-0000202" />
</device>
</communicationFunctionSnd>
<ControlActEvent>
<subject>
<RequestAvailableSlots classCode="SPLY" moodCode="RQO">
<id root="A6C66142-1DD1-11B2-9062-8F5E91AA2DD7" />
<effectiveTime>
<low value="200411090000" inclusive="true" />
<high value="200412100000" inclusive="false" />
</effectiveTime>
<location typeCode="LOC">
<clinic classCode="SDLOC">
<id root="2.16.840.1.113883.2.1.3.2.4.2" extension="DAVID" 
displayable="true" />
</clinic>
</location>
</RequestAvailableSlots>
</subject>
</ControlActEvent>
</PRSC_IN080000UK06>
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/* Code */
InputStream is = 
CabCfg.class.getClassLoader().getResourceAsStream("testdoc.xml");  // 
testdoc.xml is doc above
Document doc = new SAXReader().read(is);
Element el = doc.getRootElement();
el.add(new Namespace("", "urn:hl7-org:v3"));
Element interIdEl = (Element)(el.selectSingleNode("//interactionId"));
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=======================================================================

interIdEl returns null.


Any help with this would be greatly appreciated!

Thanks,
Barbara