Add node using JXPATH

Question

I am using jxpath to print all nodes and add a child node to the feature tag in this xml

<extracts>
<extract>
<id>1</id>
<features>
<feature>1</feature>
<feature>2</feature>
</extract>
</extracts>

This is what my code looks like (the part that works at least - it prints some information):

    import org.apache.commons.jxpath.ri.model.*;
    import org.apache.commons.jxpath.JXPathContext;
    import org.apache.commons.jxpath.Pointer;


try {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
ByteArrayInputStream bais = new ByteArrayInputStream(getBytesFromFile(file));
Document doc = builder.parse(bais);

JXPathContext jxpathCtx = JXPathContext.newContext(doc.getDocumentElement());
jxpathCtx.setLenient(true);

The first part of my requirement - which is to print these nodes -- is trivial:

for (Iterator iter2 = jxpathCtx.iterate("/extract/*"); iter2.hasNext();) 
{
    System.out.println("\n Value is : " + iter2.next().toString() +"\n");

}

The second part of my requirement is what gets to me

I need to add a new entry --a new < feature >3< /feature > node UNDER the existing <features> tag under < extract > programatically

It could be something along the lines of isolating that node - and then adding a child to it - i just dont know how to go about it :

org.apache.commons.configuration.HierarchicalConfiguration.NodeNode node = (Node)jxpathCtx.selectNodes("/extract/lastruns/lastrun");

for (Element node : nodes)
{

}

Any ideas/help would be appreciated

Answer 1

This XSLT transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:strip-space elements="*"/>

 <xsl:template match="node()|@*" name="identity">
  <xsl:copy>
   <xsl:apply-templates select="node()|@*"/>
  </xsl:copy>
 </xsl:template>

 <xsl:template match="feature[last()]">
  <xsl:call-template name="identity"/>
    <feature>3</feature>
 </xsl:template>
</xsl:stylesheet>

when applied on the provided XML document (corrected to be made well-formed):

<extracts>
    <extract>
        <id>1</id>
        <features>
            <feature>1</feature>
            <feature>2</feature>
        </features>
    </extract>
</extracts>

produces the wanted, correct result:

<extracts>
   <extract>
      <id>1</id>
      <features>
         <feature>1</feature>
         <feature>2</feature>
         <feature>3</feature>
      </features>
   </extract>
</extracts>

Explanation:

Proper use and overriding of the identity rule.