The second Public Draft of Enterprise JavaBeans 2.0 specification has been released for public review under the Java Community Process, and is available for download at http://java.sun.com/products/ejb/docs.html. Based on feedback from the expert group and the EJB community, we made several changes to the following areas in the specification. We have added a list of the significant changes since the June Public Draft to Appendix E which should provide the details regarding the changes which we highlight below: Container Managed Persistence: We have received feedback to relax the restrictions in the specification relating to the ownership of dependent objects and to allow sharing of dependent objects by multiple entity beans. This change allows a network of objects to be accessed and shared among multiple entity beans and provides the flexibility to the Bean Programmer in modelling applications. As a result of this change, we introduced requirements and protocol for dependent object creation and deletion based on expert feedback. We have introduced dependent object identity that is specified by primary keys. These modifications also allow us to be clearer about the semantics of "detached" dependent object instances. We now allow dependent objects to exist on their own in a detached state when created but not used within relationships or when removed from relationships. We have introduced a section about assignment and relationship semantics which explains the necessary conditions for relationship maintenance in full detail. EJB QL: Many of the changes for EJB QL reflect our relaxation of a number of restrictions in the CMP model or are in response to feedback we have received. We now allow queries to range over dependent object type extents, as denoted by the dependent-name deployment descriptor element and we changed the EJB QL equality semantics to reflect the introduction of primary keys for dependent objects. We have introduced the full BNF for EJB QL and eliminated the FOR clause. We made several enhancements to the EJB QL definition to incorporate basic primitive functions, expressions for testing collections and we also clarified several of the constructs and restrictions in the specification. Changes to Message-driven beans: We have removed the requirement that the MessageDrivenBean interface extend javax.jms.MessageListener, and have added the requirement that the message-driven bean class implement javax.jms.MessageListener. The reason for this change is that we wish to position EJB for future support for other types of messaging in addition to JMS. We have added the requirement that the container must support deployment of a message driven bean as a consumer of a JMS queue or durable subscription. Other changes: We have updated the sections that dealt with local transaction optimizations to reflect enhancements that will be added to the J2EE Platform spec that describe how containers may implement local transaction optimizations in a manner that is transparent to the applications. Deployment Descriptor Changes: The Deployment Descriptor is modified to be aligned with the changes that are listed above. As always, please send feedback on this draft to [EMAIL PROTECTED] Best Regards, Umit Yalcinalp and Linda DeMichiel EJB 2.0 Architects Java 2 Platform, Enterprise Edition Java Software, Sun Microsystems =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
