Creating circular generic references
- by M. Jessup
I am writing an application to do some distributed calculations in a peer to peer network. In defining the network I have two class the P2PNetwork and P2PClient. I want these to be generic and so have the definitions of:
P2PNetwork<T extends P2PClient<? extends P2PNetwork<T>>>
P2PClient<T extends P2PNetwork<? extends T>>
with P2PClient defining a method of setNetwork(T network). What I am hoping to describe with this code is:
A P2PNetwork is constituted of
clients of a certain type
A P2PClient may only belong to a
network whose clients consist of the
same type as this client (the
circular-reference)
This seems correct to me but if I try to create a non-generic version such as
MyP2PClient<MyP2PNetwork<? extends MyP2PClient>> myClient;
and other variants I receive numerous errors from the compiler. So my questions are as follows:
Is a generic circular reference even
possible (I have never seen anything explicitly forbidding it)?
Is the above generic definition a
correct definition of such a circular
relationship?
If it is valid, is it the "correct"
way to describe such a relationship
(i.e. is there another valid
definition, which is stylistically
preferred)?
How would I properly define a
non-generic instance of a Client and
Server given the proper generic
definition?
