One way to return multiple values is to return a holder of some sort with multiple values inside it. In this case you're returning multiple rows each of which has multiple columns, so you can do this trick twice.
First, make a little class that represents one row. It just needs a field per column. Create a new instance of this class per row. Then make a collection of rows, perhaps some sort of List or Set. Look into the available
Collecitons and see which looks like a good fit.
Does this sound like an interesting way to go?