But I quickly ran into a small problem. (And just as quickly, the solution.) Allow me to explain.
The problem: I want to search for nodes in the repository that have a (multivalued) "pets" attribute containing the value "dog." Note that the "pets" attribute might have multiple values. I want to filter against just one. Therefore I can't do an equality test. I must use the XPath contains() function.
My test query was:
This produced an InvalidQueryException, with a message of "Unsupported function: contains (500)".
I was a bit surprised that the servlet seemed to know nothing about any contains() function. A true "WTF moment."
Taking my hint from the stack trace, I quickly ran a Google Code Search on org.apache.jackrabbit.core.query.xpath, and immediately found the answer in XPathQueryBuilder.java: It turns out you have to use the function's qualified name, jcr:contains(). Like so:
I'm so much of an XPath newb that I don't even know if I should have been surprised by this, but it did stymie me briefly. Anyway, it works now and I'm thrilled to be able to do XPath queries right from the GET-go.