Use DOM as an argument of XSLT document() function

Question

I have in memory several DOM documents. I have not stored in file system the XML files that are represented by these DOMs. I want to process with a stylesheet
all of these DOMs (as DOMSource's) using document() function from the stylesheet. How can I refer to the secondary DOMs from document function if I haven't the files?
F.e.
<xsl:value-of select="document('file.xml')/.../..."/> file.xml only exists loaded in memory as DOM.
Can anybody help me?? Thanks

Answer 1

Thank you DrClap but I'm not sure about the use of URIResolver:
if my xslt:
<xsl:value-of select="document('file1.xml')\...\..."/>
<xsl:value-of select="document('file2.xml')\...\..."/>
I must define my own class that implements URIResolver and write my own resolve method, isn't it?
class Resuelve implements URIResolver{
     private Document doc1;
     private Document doc2;
     public Resuelve(Document doc1, Document doc2){
          this.doc1 = doc1;
          this.doc2 = doc2;
     public Source resolve(String href, String base){
          if(base.equalsIgnoreCase("file1.xml")){
               Source s1 = new DOMSource(doc1);
               return s1;
          else if(base.equalsIgnoreCase("file2.xml")){
               Source s2 = new DOMSource(doc2);
               return s2;
          else{
               return null;
I suppose that XSLT processor use automatically resolve method. I don't understand the href parameter...
Is this class correct? if not, can you show me an example please?
Thank you very much