Question

My goal : to get the root of the XML in a Node object , and then evaluate it !

My problem :

I’m trying to evaluate my expression from the ROOT of the XML file, I have this method ( I need to implement is) :

public Object evaluate(String expression, QName returnType);

Assume that I’ve already opened the XML with Document , like this :

        //load the document into a DOM Document
        this.domFactory = DocumentBuilderFactory.newInstance();

        domFactory.setNamespaceAware(true); // never forget this!

        this.builder = domFactory.newDocumentBuilder();
        this.doc = builder.parse("books.xml");

        //create an XPath factory
        this.factory = XPathFactory.newInstance();

        //create an XPath Object
        this.xpath = factory.newXPath();

Now when I do this , inside public Object evaluate(String expression, QName returnType);
:

String unitedString = " my characters " ; 
rootNode = doc.getChildNodes().item(0);
System.out.println(rootNode.getNodeName()); // this line presents the name of the root 
Object returnedObject= xpath.evaluate(unitedString,rootNode ,returnType);   // this line makes eclipse go crazy 

Eclispe says after line “4” : " DTMManagerDefault.getDTMHandleFromNode(Node) line: not available "
But in line “3” , Eclipse produces the name of the root , which is inventory …

So where did I go wrong ?

What’s wrong with it ?

Thank you all , Jack

Answer 1

first:

Your unitedString is not a valid xPath expression, it should be something like /root/node/ xPath’s describe paths to (a) specific node(s) to in your xml file.

second:

The root node of any xml is a special node called the DocumentElement, you can get to it by calling doc.getDocumentElement()