A resource reference is an element in a deployment descriptor that identifies the component’s coded name for the resource. More specifically, the coded name references a connection factory for the resource. In the example given in the following section, the resource reference name is jdbc/SavingsAccountDB.
The JNDI name of a resource and the name of the resource reference are not the same. This approach to naming requires that you map the two names before deployment, but it also decouples components from resources. Because of this de-coupling, if at a later time the component needs to access a different resource, the name does not need to change. This flexibility also makes it easier for you to assemble J2EE applications from preexisting components.
The following table lists JNDI lookups and their associated references for the J2EE resources used by the Application Server.
Table 6–1 JNDI Lookups and Their Associated References
JNDI Lookup Name |
Associated Reference |
---|---|
java:comp/env |
Application environment entries |
java:comp/env/jdbc |
JDBC DataSource resource manager connection factories |
java:comp/env/ejb |
EJB References |
java:comp/UserTransaction |
UserTransaction references |
java:comp/env/mail |
JavaMail Session Connection Factories |
java:comp/env/url |
URL Connection Factories |
java:comp/env/jms |
JMS Connection Factories and Destinations |
java:comp/ORB |
ORB instance shared across application components |