Well I don't really know too much Java but I know some c# which is extremely similar (I actually helped my friend debug a simple Java game :p)
What you could do is make a list, every time someone deposits something add an element to the list, when the command is done, display all the elements in the list (idk how to do this but it must be relatively simple).
EDIT:Since you couldn't add 2 seperate variables to one list (username and deposits it value), you would have to make a new variable that's requires 2 of them (user and value) I'll call it history. Then when you deposit you make a new history and add it to the list, then when you want to display it, you would instead display the values of each history in the list.
Does that make sense? I'm a pretty amature programmer.
@reggles44 does that make sense?