WebSphere extensions to the Enterprise JavaBeans specification

This article outlines extensions to the Enterprise JavaBeans (EJB) specification that WebSphere Applicaion Server provides.

• 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. WAS 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.

  For more information, see the documentation for the IBM WebSphere Studio Application Developer product.

• Optimistic concurrency control for container-managed persistence

  WAS supports optimistic concurrency control of data access. For more information on concurrency control, see Concurrency control.

• Access intents for EJB persistence

  WAS supports the application of named data-access policies at the method level. For more information, see Access intent policies.

• Performance enhancements

  Through the lifetime-in-cache settings, WAS provides a way for you to improve performance for beans that are only occasionally updated. For more information, see Entity bean assembly settings .

  Some enterprise beans created with the IBM WebSphere Studio Application Developer product 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

  WAS supports IBM extensions of assembly and deployment options. IBM extensions are clearly marked in reference topics for assembly settings. For more information, see Assembly settings.