xPath and namespace problem

[Jeppe Sommer]

Hello,

I am trying to query a xml file using xPath, but I am having some problem as I guess the xml file has namespace declarations.

I am trying to get the text of the element called: /Invoice/com:ID, but I just get a nullpointer.

Here is my code:

SAXBuilder saxBuilder = new SAXBuilder("org.apache.xerces.parsers.SAXParser", false );
Document doc = saxBuilder.build( "D://oioxml.xml" );
 
Namespace ns_com = Namespace.getNamespace("com", "http://rep.oio.dk/ubl/xml/schemas/0p71/common/");
 
org.jdom.xpath.XPath xp = org.jdom.xpath.XPath.newInstance("/Invoice/com:ID");
xp.addNamespace( ns_com );

org.jdom.Element myElement = ( ( org.jdom.Element )( xp.selectSingleNode ( doc ) ) );
 
if ( myElement != null ){
 
System.out.println("********* :"+myElement.getText() );
}

Here is the XML file:

<?xml version="1.0" encoding="UTF-8" ?> 
<Invoice xmlns="http://rep.oio.dk/ubl/xml/schemas/0p71/testpie/" xmlns:com="http://rep.oio.dk/ubl/xml/schemas/0p71/common/" xmlns:main="http://rep.oio.dk/ubl/xml/schemas/0p71/maindoc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:schemaLocation="D://programmer/resin-3.1/webapps/rekvisition/module/oioxml/ubl/xml/schemas/pieLax.xsd" xmlns:cp="http://www.cateringportal.dk/ubl/xml/schemas/0p71/common/">
<com:ID>9999-544</com:ID> 
...

Does anyone know what I do wrong?

Thanks in advance...

[Phil Fearon]

You're nearly there.

The problem is that XPath 1.0 doesn't understand the default namespace that is declared as:

xmlns="http://rep.oio.dk/ubl/xml/schemas/0p71/testpie/"

Try specifying a prefix for this namespace instead such as:

Namespace ns_com = Namespace.getNamespace("def", "xmlns="http://rep.oio.dk/ubl/xml/schemas/0p71/testpie/");

You should then be able to access the node using the following:

org.jdom.xpath.XPath xp = org.jdom.xpath.XPath.newInstance("/def:Invoice/com:ID");

[Jeppe Sommer]

Dear Phil,

Thanks for your reply.

I tried the following code but it still doesn�t work?! I am wondering if I have to to declare all the namespaces or just the one I want to access? Anyway I have tried to declare all namespaces but without a result.

Namespace ns_com = Namespace.getNamespace("com", "http://rep.oio.dk/ubl/xml/schemas/0p71/common/");
Namespace ns_def = Namespace.getNamespace("def", "xmlns=http://rep.oio.dk/ubl/xml/schemas/0p71/testpie/");
 
org.jdom.xpath.XPath xp = org.jdom.xpath.XPath.newInstance("/def:Invoice/com:ID");
xp.addNamespace( ns_com );
xp.addNamespace( ns_def );
 
org.jdom.Element e_bookValueDate = ( ( org.jdom.Element )( xp.selectSingleNode ( doc ) ) );
 
if ( e_bookValueDate != null ){
 
//It never prints out this line   
System.out.println("*********** "+e_bookValueDate.getText() );
}

Here is the XML code:

<?xml version="1.0" encoding="UTF-8" ?> 
- <Invoice xmlns="http://rep.oio.dk/ubl/xml/schemas/0p71/testpie/" xmlns:com="http://rep.oio.dk/ubl/xml/schemas/0p71/common/" xmlns:main="http://rep.oio.dk/ubl/xml/schemas/0p71/maindoc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:schemaLocation="D://programmer/resin-3.1/webapps/rekvisition/module/oioxml/ubl/xml/schemas/pieLax.xsd" xmlns:cp="http://www.cateringportal.dk/ubl/xml/schemas/0p71/common/">
  <com:ID>9999-544</com:ID>

[kadavul seelan]

Hye,
Are you find a solution?

[g tsuji]

The revised code segment as posted in posted Friday, May 30, 2008 5:46 PM should be working for the purpose. If it does not work out rightaway, it is only because of the conditioning where the segment is expected to execute, such as defective classpath or import statements or exception throwing...