The J2EE specification provides a means for J2EE components to refer to resource manager connection factories by using "logical" names called resource manager connection factory references. You can use the deployment descriptor editors to define resource manager connection factory references.
A resource manager connection factory is an object that is used to create connections to a resource manager. For example, an object that implements the javax.sql.DataSource interface is a resource manager connection factory for java.sql.Connection objects that implement connections to a database management system.
At deployment, the resource manager connection factory references are bound to the actual resource manager connection factories that exist in the target operational environment.
Resource manager connection factory objects that are accessed through a reference are only valid within the component instance that performed the lookup.
For each resource manager connection factory reference that you define, a resourece-ref element is added to the deployment descriptor for that application component. The references are scoped to the application component where they are defined, so they are not accessible to other application components during run time. Other components can define resource manager connection factory references with the same name without causing a name conflict.
To define a resource manager connection factory reference: