SPARQL QUERY using a URI

I'm doing the SPARQL query below (using Jena) where uriNode is a
Stringrepresenting a
URI. But this query doesn't give me any result. I've already checked the
database and this URI does exist there.

*what's the problem?*


*QUERY:*

String queryString2 = "PREFIX rdf:
<http://www.w3.org/1999/02/22-rdf-syntax-ns#> " +
                    "PREFIX dc: <http://purl.org/dc/elements/1.1/>
SELECT ?author WHERE { " +
                    "?document dc:creator ?author." +
                    "FILTER (?document = \"" + uriNode + "\" ). }";

Thank you!