I got past this, not sure if this is the only solution as I am so new to this, but I do know that what I changed did make the error go away.
The problem appeared to be here :
The object patients was a java.util.List. It looks like the find method of getHibernateTmeplate looks for an array there. I took my list of Strings, created an array of Strings ( String ) and passed that instead. This worked.