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.

For more information, see the documentation for the assembly tools.

Optimistic concurrency control for container-managed persistence

This product supports optimistic concurrency control of data access. For more information, see the 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, you can prevent certain types of database-related exceptions from occurring during the run time of your EJB application. Within each group you specify the order in which the beans update your 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 concepts
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
Related tasks
Setting the run time for CMP sequence groups
Developing enterprise beans
Related information
Rational Application Developer documentation
Reference topic Reference topic    

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