Compatibility Statement for BEA WebLogic Server 9.0
BEA attempts to support binary and source-level compatibility between the current version of WebLogic Server and all versions as far back as 7.0 in the areas of persistent data, generated classes, and API compatibility. In some cases, it is impossible to avoid incompatibilities. Where incompatibilities arise, they are fully documented in the Upgrading WebLogic Application Environments guide.
J2EE 1.4 Compatibility
BEA WebLogic Server is one hundred percent J2EE 1.4 compatible across all operating system platforms for a given WebLogic Server release. This allows a J2EE 1.4 compliant application to be developed on one operating system platform (such as a Windows platform) and deployed for production on another (such as UNIX, Linux, Tru64, OpenVMS, or HP NonStop), without requiring J2EE application code changes. BEA ensures this compatibility of J2EE application portability within a WebLogic Server release level.
Persistent Data Compatibility
Upgrading to WebLogic Server 9.0 does not require you to make any changes to WebLogic Server 7.0 or 8.1 persistent data storage, including configuration files, deployment descriptors, transaction logs, and JMS messages.
Generated Classes Compatibility
With one exception, upgrading to WebLogic Server 9.0 does not require you to recompile applications in order to create new generated classes.
The 9.0 version of the EJBGen utility recognizes only JDK 5.0 metadata annotation-style EJBGen tags and not the old Javadoc-style tags. This means that source files that use the Javadoc-style tags must be upgraded to use the equivalent annotation, and then recompiled using the 9.0 version of EJBGen.
WebLogic Server 7.0 and 8.1 applications deployed on WebLogic Server 9.0 will function without modification. Exceptions to this rule include cases where API behavior was changed in order to conform to a specification or to fix incorrect behavior. In certain circumstances, a correction may cause your application to behave differently.
Interoperability between WebLogic Server 9.0 and WebLogic Server 7.0 and 8.1 is supported in the following scenarios:
See JMX 1.2 Implementation in Upgrading WebLogic Application Environments.