I have a many to many association using a join table, and the join table has some additional information.

In one case that additional info is a flag. Class A is many to many with class B, plus there is a flag. Like this:

Table A
A_ID

Table B
B_ID

Table A2B
A_ID
B_ID
FLAG

When I query to get all the object B in A that are flagged I can just use the column, but how do I properly represent the flag in the model so I can set it?

I have a similar scenario where I want to store a date on the join table (the date the association is created in this case).

(I'm using Hibernate3)