Suppose you have two EntityBean classes A and B which share some common
functionality and state by inheriting from the same superclass S. Then, if S
has some member variable, say a java.util.Vector called "foos", which is
part of the persistent state of both A and B, my question is this: When
should "foos" be initialized?
I am positive that the ejbCreate methods of A and B could include an
instantiation like "foos = new Vector();" but if I use this model, I have to
remember to write this instantiation into every subclass of S, and if S has
many member variables (and many subclasses) that becomes error prone. - Not
to mention that if I add a new member variable to S I have to modify all
subclasses A, B, etc. to make their ejbCreate(...) instantiate this new
variable.
My own suggestion is to define a method in S, lets call it "void
instantiateS()" and have subclasses A, B, etc. invoke this method in their
ejbCreate(...).
I believe this method should *not* be the (no-arg) constructor of S as I
expect this contructor will be called everytime an instance of A or B is
loaded from persistant storage (which is unnecessary).
What are your suggestions?
What do you do when using inheritance in your beans?
Any comments would be appreciated.
Randahl.
