Working with Query classes

[Matt Honeycutt]

Is there a "good" way to work with Query and its concrete implementations?
I'd like to display a graphical representation of the user's query.  We're
parsing the user's input using the standard QueryParser class.  What I'd
like to do is extract all the criteria from the query and display them, but
I don't see anything in the abstract Query class that is suitable for this.
Is my only option to switch off the concrete type and treat each one
differently, or am I overlooking some simpler solution?