Help need with transforming Java lists/collections or something

Question

I have a list of objects returned from getJdbcTemplate().query

that look like this

object(test,test,test,1)
object(test,test,test,2)
object(test,test,test,3)

How can I transpose these into one object that looks like this

object(test,test,test,list<t>({1,2,3}))

Hopefuly you get the idea from my ropey psuedo object representation :)