Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Developer's Guide

- Previous: Accessing EJB Components Using the CosNaming Naming Context
- Next: Naming Environment for Lifecycle Modules

## Accessing EJB Components in a Remote Application Server

The recommended approach for looking up an EJB component in a remote Application Server from a client that is a servlet or EJB component is to use the Interoperable Naming Service syntax. Host and port information is prepended to any global JNDI names and is automatically resolved during the lookup. The syntax for an interoperable global name is as follows:

    corbaname:iiop:host:port#a/b/name

This makes the programming model for accessing EJB components in another Application Server exactly the same as accessing them in the same server. The deployer can change the way the EJB components are physically distributed without having to change the code.

For J2EE components, the code still performs a `java:comp/env` lookup on an EJB reference. The only difference is that the deployer maps the `ejb-reference` element to an interoperable name in an Application Server deployment descriptor file instead of a simple global JNDI name.

For example, suppose a servlet looks up an EJB reference using `java:comp/env/ejb/Foo`, and the target EJB component has a global JNDI name of `a/b/Foo`.

The `ejb-ref` element in `sun-web.xml` looks like this:

    <ejb-ref>
       <ejb-ref-name>ejb/Foo</ejb-ref-name>
       <jndi-name>corbaname:iiop:host:port#a/b/Foo</jndi-name>
    <ejb-ref>

The code looks like this:

    Context ic = new InitialContext();
    Object o = ic.lookup("java:comp/env/ejb/Foo");

For a client that doesn’t run within a J2EE container, the code just uses the interoperable global name instead of the simple global JNDI name. For example:

    Context ic = new InitialContext();
    Object o = ic.lookup("corbaname:iiop:host:port#a/b/Foo");

Objects stored in the interoperable naming context and component-specific (`java:comp/env`) naming contexts are transient. On each server startup or application reloading, all relevant objects are re-bound to the namespace.

- Previous: Accessing EJB Components Using the CosNaming Naming Context
- Next: Naming Environment for Lifecycle Modules

- © 2010, Oracle Corporation and/or its affiliates