I am using hibernate version 3.3 to persist my class STUDENT. I am using derby as the underlying database. I want to set id using some generator when the id is not given to my Student entity class and use the existing id if its given to INSERT a record into STUDENT table.
Can any one guide me how would my annotation look like for student id property?
Does derby support sequence in the first place? If so how do I create sequence in derby?
How will my dao save method look like?

This is how I am planning to do it as I think derby does not support sequence as of now.
1) create a sequence table to store seed and manage next val.
2) Implement IdentifierGenerator and based on whether entity id property is set or not; in the generate method return the next val or existing id.
3) For the entity the id genrator will be annotated with GenericGenerator and appropriate properties to get the table names etc are set with the parameter annotation.

Any thoughts?