Is the struts example itself is multi-thread safe?

[Maya Muchnik]

Hi,

In "A Walking Tour of the Struts App", the author has mentioned that "There is only 
one object for each action (URI), so your action objects must be
multi-thread safe". Is the example itself is multi-thread safe?
I am asking this, because are several actions here, but not one of them use 
"synchronized" statement.

Maybe I am missing something...

THANKS in advance.

Maya