How to update/insert/delete an element from an XML document

[Ajan Balakrishnan]

Hi folks,
I have a sample XML document,

<doc>
  <package id=1>
     <service id=1>
     <service id=2>
     <service id=3>
  </package>
  <package id=2>
     <service id=1>
     <service id=2>
     <service id=3>
  </package>
</doc>

How to delete <service id=1> from <package id=1> and insert a new service, say <service id=4> within <package id=1> using a java program. I know how to read a node and stuff but not delete and insert. Any sample code is greatly appreciated

Thanks
AJan

[Ajan Balakrishnan]

Any luck for me guys

[Laurent Kempeneers]

I think the best to do when you have to manipulate a DOM in memory and querying in it, is to work with XPath. With XPath you can reach easily the node you are looking for and after you can manipulate it.
This is an example for removing a node:
****
Node aNode = ... result of an XPath query ...
Node parentNode = aNode.getParentNode();
parent.removeChild(aNode);
****
This is an example of a function for retrieving a list of nodes belonging to an XPath expression. This example works with Xalan.
public NodeList findNode(Document doc, String query) throws SAXException {
// query = xpath expression
// doc = the DOM object representing the XML document you want manipulate.
XPath xPath = new XPath();
XPathSupport xpathSupport = new XMLParserLiaisonDefault();
XPathProcessorImpl parser = new XPathProcessorImpl(xpathSupport);
PrefixResolverDefault prefixResolver = new PrefixResolverDefault(doc.getDocumentElement());
parser.initXPath(xPath, query, prefixResolver);
XObject xObject = xPath.execute(xpathSupport, doc.getDocumentElement(), prefixResolver);

return xObject.nodeset();
}

[Ajan Balakrishnan]

Thanks a lot Laurent

[ravi_r]

Originally posted by Laurent Kempeneers:
I think the best to do when you have to manipulate a DOM in memory and querying in it, is to work with XPath. With XPath you can reach easily the node you are looking for and after you can manipulate it.
This is an example for removing a node:
****
Node aNode = ... result of an XPath query ...
Node parentNode = aNode.getParentNode();
parent.removeChild(aNode);
****
This is an example of a function for retrieving a list of nodes belonging to an XPath expression. This example works with Xalan.
public NodeList findNode(Document doc, String query) throws SAXException {
// query = xpath expression
// doc = the DOM object representing the XML document you want manipulate.
XPath xPath = new XPath();
XPathSupport xpathSupport = new XMLParserLiaisonDefault();
XPathProcessorImpl parser = new XPathProcessorImpl(xpathSupport);
PrefixResolverDefault prefixResolver = new PrefixResolverDefault(doc.getDocumentElement());
parser.initXPath(xPath, query, prefixResolver);
XObject xObject = xPath.execute(xpathSupport, doc.getDocumentElement(), prefixResolver);

return xObject.nodeset();
}

How to import the XPath and other related classes?