Signing fragment element using XML XPATH transformer

[Hess Yvan]

Hi,

I would like to sign only a fragment (edoc:metadata) of my XML document
using an enveloped signature. Can somebody help me by giving me an example. 

I did like that but I am not sure I am right and I don't uderstand
XPathContainer class and xpath.getElement() result

         Transforms transforms = new Transforms(xmlDocument);
         
         XPathContainer xpath = new XPathContainer(xmlDocument);
         xpath.setXPathNamespaceContext("ds", Constants.SignatureSpecNS);
         xpath.setXPath("/edoc:e-document/edoc:metadata");
         

         transforms.addTransform(Transforms.TRANSFORM_ENVELOPED_SIGNATURE);
 
transforms.addTransform(Transforms.TRANSFORM_XPATH,xpath.getElement());
 
         sig.addDocument("", transforms, Constants.ALGO_ID_DIGEST_SHA1);

 
Thanks for your answer 

Yvan Hess