how to merge two documents in memory

[mathew Jackson]

This may be a simple question or it may be a really tough one.
I have two xml documents that have been created and sent via servlets to another java app. I need to merge data from one document into the other without storing either to disk.
I know how to use the document() function if the document called is saved somewhere but how can I do it if they are both in memory?
Any help would be appriciated.

[Ajith Kallambella]

Assuming you have two documents in memory say document1 and document2, parsed as DOM trees, here's the code that will merge the documents

Document doc = new DocumentImpl();
Element root = doc.createElement( "MergedDocument" );
doc.importNode( document1.getDocumentElement(),true);  // see <a href="http://java.sun.com/xml/jaxp/dist/1.1/docs/api/org/w3c/dom/Document.html" target="_blank" rel="nofollow">Document.importNode() </a>
doc.importNode( document2.getDocumentElement(),true); 

Hope that helps!

[mathew Jackson]

I wish my problem were that simple. I need to basically pass one document through an xslt. In the xslt is a call to document(). what I need is to make that call to document() to a doc in memory rather than to one at a uri.
Instead of:
<xsl:variable name="myDoc" select="http://www.document.com"/>
I need:
<xsl:variable name="myDoc" select="SOME DOC VARIABLE IN THE APP"/>
Any one?

[Ajith Kallambella]

Sounds to me like you will have to perform in-memory transformation. Merge the two documents as I suggested in the above step. Then create a DOMSource with the root node.

Use the JAXPTransformer class, or for that matter any XSLT to apply the stylesheet in memory to obtain a DOMResult.
Checkout JAXP download for example programs.
Alternatively, you can use a publishing framework such as Cocoon to do in-memory tranformations.