setNamespaceAware problem !!

[faris shomou]

I�m trying to pars un xml file (below), with setting �setNamespaceAware(false)�

My string s is always empty, I do not why.

I someone can help me, thanks in advance,

[e-mail]
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My xml file:
<?xml version="1.0" encoding="UTF-8"?>
<fs:Faris xmlns:fs="http://www.test.com">
<fs:Acknowledgement Receiver="salam" Sender="faris">
<fs:UUId>12322222</fs:UUId>
</fs:Acknowledgement>
</fs:Faris>

my code:
----------------------------------------------------
// JAXP
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;

// DOM
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(false);
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(new File("C:\\mytest.xml"));
XPath xpath;
xpath = XPathFactory.newInstance().newXPath();

String s = (String)xpath.evaluate("//Acknowledgement//@Receiver", doc,
XPathConstants.STRING);
System.out.println(s);


---------------------------------------------------------------





<?xml version="1.0" encoding="UTF-8"?>
<fs:Faris xmlns:fs="http://www.test.com">
<fs:Acknowledgement Receiver="salam" Sender="faris">
<fs:UUId>12322222</fs:UUId>
</fs:Acknowledgement>
</fs:Faris>

[Paul Clapham]

You didn't specify the namespace in your XPath object. I haven't used that class before but I see it has a "setNamespaceContext" method. And I am guessing you would have to include the namespace prefix in your XPath expression too.

[faris shomou]

Thank you for yore reponce.

The problem is that i do not know what is the prefix for the namesapace.

I want ust to use the xpath without the namesapace prefix.

[Paul Clapham]

The namespace prefix is part of the element name, or more precisely the namespace prefix is a surrogate for the namespace URI, which is part of the element name. So you need to know the namespace URI to create an XPath object that can find nodes involving that namespace. I have been looking at the API documentation and it looks to me like you have to do this:

// Create an XPath object
XPath xp = XPathFactory.newInstance().newXPath();
// Create a NamespaceContext for the namespace
// (Simplest possible version -- may be too simple)
NamespaceContext nc = new NamespaceContext() {
  public String getNamespaceURI(String prefix) {
    return "http://www.test.com";
    // This must match the URI in the XML document
  }
  public String getPrefix(String namespaceURI) {
    return "abc";
    // This can probably be anything but it must match the prefix in your
    // XPath expression
  }
  public Iterator getPrefixes(String namespaceURI) {
    return null;
    // You might have to do some work here. I have no idea.
  }
};
// Assign it to the XPath object
xp.setNamespaceContext(nc);
// Evaluate the expression
String s =
    (String)xpath.evaluate("//abc:Acknowledgement//@Receiver", doc, XPathConstants.STRING);

Now, I haven't ever tried this, so it is quite likely to have problems. So now it's your turn to hack around with it until you get it to work.

Note that you DO need to know the namespace URI of the element you are searching for. If you don't know that then you have a design problem.

[faris shomou]

I do like to thank you again, the problem is each time my client change his namespace�s prefix, so I�m asking if I could eliminate all the namespaces dynamically and the I can use the xpath without prefixes:

String s =
(String)xpath.evaluate("//Acknowledgement//@Receiver", doc, XPathConstants.STRING);

[Paul Clapham]

Namespace prefix doesn't matter. That's why your client can change it every time. It's the namespace URI that should not change.