Ссылка на контекст из которого локапятся бины

Может это прояснит, хотя последнего вопроса я не понял -

The J2EE platform does define a limited naming policy for application components (read "comp"). This namespace is rooted with "java:comp". "comp" provides a sub-tree for component related bindings. "env" is bound to a sub-tree for component environment-related bindings, as defined in the components deployment descriptor. A typical setup for the "env" namespace is:

java:comp/env/ejb/{binded EJBs}
java:comp/env/jdbc/{binded JDBC datasources}
java:comp/env/jms/{binded JMS connection factories}
java:comp/env/mail/{binded Java mail connection factories}

"java:comp/env" is the namespace that a J2EE container uses to tie logical names to the various components being managed by the container.