inheritance and relationships with EJB?


EJB design: inheritance and relationships with EJB?

  1. inheritance and relationships with EJB? (2 messages)


    i'm trying to figure out if EJB 1.1 supports inheritance and 1:1, 1:M, and M:N type relationships. it looks to me that j2ee currently supports the 3 relationships, but only for bean-managed persistence. not sure about inheritance though. can anyone shed any light?


  2. Hi,

    Inheritance is supported by EJB 1.1 for certain limits. Probably, if you will have advanced (deep, complicated) inheritance relationship between you classes you can run into the trouble.
    I think there is the way to implement 1:1, 1:M, N:M relationships in CMP and BMP EJBs. One problem in CMP that you cannot map single EJB to multiple tables and your finder cannot search across multiple tables.
    There are number of Application Servers that almost ready for EJB 2.0 and they have their own implementation for using EJB relationship on CMP but until EJB 2.0 will be release, it is just proprietary solution.

    Best regards,


  3. see the ibm redbook for EJB development using Visual age java for some material on inheritance and relationship.