If you want to develop an XQJ application, you will find the classes of the CentraSite XQJ implementation in the jar file rts/bin/xqj.jar under the CentraSite installation location.

You can use the CentraSite XQJ interface to perform an XQuery on the basis of a standard XQExpression or an XQPreparedExpression. With a standard XQExpression, the query is parsed each time it is executed. If a query is to be executed many times, it can be more efficient to use an XQPreparedExpression, which is parsed only once.