Configuring Applications

Of course, the driving purpose of a J2EE server is the configuration and deployment of J2EE applications. Fortunately, most of your server-side code can be portable and doesn't need to change to run within OC4J. However, like most other J2EE servers, OC4J extends basic J2EE with additional features that can be configured through server-specific configuration files, which in turn get packaged and deployed alongside the standard J2EE deployment descriptors.

For example, in addition to the standard ejb-jar.xml that defines EJBs, transaction attributes, and security settings, you can include an orion-ejb-jar .xml that maps fields to underlying tables and columns and configures the database isolation level.

Table 4-9 maps each J2EE descriptor to the corresponding OC4J descriptor and indicates where this is covered in the book.

Table 4-9: Mapping OC4J Deployment Descriptors to J2EE Deployment Descriptors

J2EE Descriptor	OC4J Descriptor	Refer To
application.xml	orion-application.xml	Chapter 9
web.xml	orion-web .xml	Chapter 10
ejb-jar.xml	orion-ejb-jar.xml	Chapter 11
ra.xml	oc4j-ra.xml	Chapter 12
application-client .xml	orion-application-client.xml	Chapter 13

Once you've customized all of your descriptors and packaged the application, you can deploy and run it without any further configuration. See Chapter 9 for more information about J2EE packaging and deployment.