WebSphere extensions to the Enterprise JavaBeans specification
This topic outlines extensions to the Enterprise JavaBeans (EJB) specification provided with the product.
Inheritance in enterprise beans
In the Java language, inheritance is the creation of a new class from an existing class or a new interface from an existing interface. This product supports two forms of inheritance: standard class inheritance and EJB inheritance.
In standard class inheritance, the home interface, remote interface, or enterprise bean class inherits properties and methods from base classes that are not themselves enterprise bean classes or interfaces.
By contrast in enterprise bean inheritance, an enterprise bean inherits properties, such as container-managed persistence (CMP) fields and container-managed relationship (CMR) fields, methods, and method-level control descriptor attributes from another enterprise bean.
See documentation for the assembly tools.
Optimistic concurrency control for container-managed persistence
This product supports optimistic concurrency control of data access. See topic about concurrency control.
Access intents for EJB persistence
This product supports the application of named data-access policies.
Sequence grouping for container-managed persistence
By designating CMP sequence groups for entity beans, we can prevent certain types of database-related exceptions from occurring during the run time of our EJB application. Within each group we specify the order in which the beans update our relational database tables. For instructions, see the topic about setting the run time for CMP sequence groups.
Performance enhancements
Through the lifetime-in-cache settings, this product provides a way for you to improve performance for beans that are only occasionally updated. For more information, see the topic about entity bean assembly settings in the assembly tool documentation.
Some enterprise beans created with the assembly tools can utilize read-ahead for loading a bean and its related beans in a single database operation. An entire object graph or any part of the graph can be preloaded by configuring a finder method to use read-ahead.
Assembly and deployment extensions
This product supports IBM extensions of assembly and deployment options.
Related:
Development and assembly tools Concurrency control Access intent policies for EJB 2.x entity beans Read ahead scheme hints Sequence grouping for container-managed persistence in assembled EJB modules Set the run time for CMP sequence groups Developing enterprise beans Assembling EJB modules Rational Application Developer documentation