question regarding setting anyURI from java

Hi all,

I am trying to get the below query working but i have trouble setting the
variable from Java.  If I use java.net.URI i get following
exception:javax.xml.xquery.XQException: Java object cannot be converted to an
XQuery value

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declare variable $uri as xs:anyURI external;
doc($uri)
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Can someone shed some light on this?

Thx in advance,
Robby