Network Deployment (Distributed operating systems), v8.0 > Migration and coexistence > Migrate EJB applications
Migrate enterprise bean code to the supported specification
Support for the EJB 3.1 specification is added for this product. There are no migration issues associated with using EJB 3.x beans. Existing applications continue to run as-is and compile without error.
The EJB 3.0 and EJB 3.1 specifications have deprecated the use of EJB 1.1 style entity beans. While using EJB 2.x and earlier modules in the product has not yet been deprecated, you are encouraged to start migrating to Java Persistence API (JPA) or JDBC. Follow these steps as appropriate for your application deployment.
Procedure
- Modify enterprise bean code for changes in the specification.
- We must migrate the v1.1 beans to v2.x beans and redeploy them on the product.
The EJB v2.0 specification mandates that before the EJB container runs a findByMethod query, the state of all enterprise beans enlisted in the current transaction be synchronized with the persistent store. This synchronization is done so that the query is performed against current data. When Version 1.1 beans are reassembled into an EJB 2.x-compliant module, the EJB container synchronizes the state of v1.1 beans, as well as that of v2.x beans. As a result, you might notice some change in application behavior even though the application code for the Version 1.1 beans has not been changed.
- Ensure WAS 32-bit to 64-bit compatibility. This is not an issue for a pureJava application. However, if the application code uses the Java Native Interface (JNI) code, be aware of the following considerations: the JNI allows Java code running in a virtual machine to operate with applications and libraries written in other languages, such as C, C++, and assembly. Therefore, if your J2EE application uses JNI in a 32-bit environment, your code must be recompiled in the 64-bit environment. It is possible that the JNI calls could be different after the compilation, as the JNI specifications can change from version to version.
- Reassemble and redeploy all modules to incorporate migrated code.
Related
Migrate enterprise bean code from v1.1 to v2.1
Adjust exception handling for EJB wrapped applications migrating from version 5 to version 7
Enterprise beans
Migrate applications to use data sources of the current Java EE Connector Architecture (JCA)
Task overview: Using enterprise beans in applications