How to pass variable parameter into XPath expression?

by

Given that you’re using the Axiom XPath library, which in turn uses Jaxen, you’ll need to follow the following three steps to do this in a thoroughly robust manner:

  • Create a SimpleVariableContext, and call context.setVariableValue("val", "value1") to assign a value to that variable.
  • On your BaseXPath object, call .setVariableContext() to pass in the context you assigned.
  • Inside your expression, use /a/b/c[x=$val]/y to refer to that value.

Consider the following:

package com.example;

import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.impl.common.AxiomText;
import org.apache.axiom.om.util.AXIOMUtil;
import org.apache.axiom.om.xpath.DocumentNavigator;
import org.jaxen.*;

import javax.xml.stream.XMLStreamException;

public class Main {

    public static void main(String[] args) throws XMLStreamException, JaxenException {
        String xmlPayload="<parent><a><b><c><x>val1</x><y>abc</y></c>" +
                                        "<c><x>val2</x><y>abcd</y></c>" +
                          "</b></a></parent>";
        OMElement xmlOMOBject = AXIOMUtil.stringToOM(xmlPayload);

        SimpleVariableContext svc = new SimpleVariableContext();
        svc.setVariableValue("val", "val2");

        String xpartString = "//c[x=$val]/y/text()";
        BaseXPath contextpath = new BaseXPath(xpartString, new DocumentNavigator());
        contextpath.setVariableContext(svc);
        AxiomText selectedNode = (AxiomText) contextpath.selectSingleNode(xmlOMOBject);
        System.out.println(selectedNode.getText());
    }
}

…which emits as output:

abcd

More Related Contents:

  1. How can I use XPath to find the minimum value of an attribute in a set of elements?
  2. How to find the max attribute from an XML document using Xpath 1.0
  3. How does XPath deal with XML namespaces?
  4. How to parse XML in Bash?
  5. XPath contains(text(),’some string’) doesn’t work when used with node with more than one Text subnode
  6. XPath query to get nth instance of an element
  7. Current node vs. Context node in XSLT/XPath?
  8. XPath to select element based on childs child value
  9. how to ignore namespaces with XPath
  10. Xml Namespace breaking my xpath!
  11. How to select following sibling/XML tag using XPath
  12. XPath to select multiple tags
  13. Using XPATH to search text containing  
  14. XSLT: How to convert XML Node to String
  15. XPath with multiple conditions
  16. How to ignore namespace when selecting XML nodes with XPath
  17. Finding the difference between two dateTimes in XSLT
  18. What is the difference between // and .// in XPath?
  19. If double slash (//) is used 2 times in XPath, what does it mean?
  20. XSLT Replace function not found
  21. Using XPath, How do I select a node based on its text content and value of an attribute?
  22. Concatenate multiple node values in xpath
  23. How to insert a new element under another with xmlstarlet?
  24. distinct in Xpath?
  25. How can I select an element with multiple classes with Xpath?
  26. What browsers support Xpath 2.0?
  27. WiX Installer: using xslt with heat.exe to update attributes
  28. XPath on an XML document with namespace
  29. xpath expression from xml with namespace prefix
  30. Is it possible to apply normalize-space to all nodes XPath expression finds?

Leave a Comment