private Data dereference(XMLCryptoContext context) throws XMLSignatureException { Data data = null; // use user-specified URIDereferencer if specified; otherwise use deflt URIDereferencer deref = context.getURIDereferencer(); if (deref == null) { deref = DOMURIDereferencer.INSTANCE; } try { data = deref.dereference(this, context); if (log.isLoggable(Level.FINE)) { log.log(Level.FINE, "URIDereferencer class name: " + deref.getClass().getName()); log.log(Level.FINE, "Data class name: " + data.getClass().getName()); } } catch (URIReferenceException ure) { throw new XMLSignatureException(ure); } return data; }