How to force a one-element collection to render in json as an array?

[KARR, DAVID]

I have a colleague who complained to me about CXF's JSON handling.  He said 
that he couldn't figure out how to force CXF's JSON handling to render a JSON 
array for a one-element collection.  It was rendering it as a plain field.  I 
haven't looked into this, but is there an obvious way to deal with this?