normaly I make department bean and location bean and set up M:M association,I will have tables: department ,location, locDept

but,I have a tables:codetable,association:

codetable:

codetype codevalue description
--------------------------------
department 1 HR
department 2 IT
location 1 Toronto
location 2 new york
...others codes....

and an assoication table to associate department and location like

assoctype priAssoc secAssoc
-----------------------------
locdept 1 1
locdept 2 1
...others association....

as I learnt from EJB2.1 CMR relationship i should make a entity bean for codetable,but not for association table,but in this case,how can i make bean and set up relationship?