Clarification for client JNDI lookups needed

Question

Hello,
While analyzing j2eeguide directory samples under iAS 6.0 SP3 I could see that this code is used on the client side for JNDI lookups (from warehouse example):
Properties env = new Properties();
env.put("java.naming.factory.initial",
"com.sun.jndi.cosnaming.CNCtxFactory");
env.put("java.naming.provider.url", "iiop://" + host + ":"+port);
Context initial = new InitialContext(env);
Object objref = initial.lookup("ejb/MyWarehouse");
In runtime deployment descriptor for this sample we have these lines:
<ias-ejb-jar>
<enterprise-beans>
<session>
<ejb-name>MyWarehouse</ejb-name>
<guid>{a430b5c0-673f-11d4-a025-0010a4e78552}</guid>
Does it mean that iAS automatically places beans under java:comp/env/ejb directory? This is recommended (but not required) place by J2EE 1.3 spec. For other AppServers I need explicitly specify through <jndi-name> clause (in form <jndi-name>ejb/MyWarehouse</jndi-name>) in which place my bean should be placed and thus could put them under for example java:comp/env/testejb/MyWarehouse. Any comments on this?
Thank you,
Andrejus

Answer 1

I'm using a Singleton class to cache HomeInterfaces. The first time a
HomeInterface is requested, the JNDI lookup is done, after that, all
requests to that HomeInterface are handled by the cache. Works great, no
problems. AFAIK there are no problems with storing the HomeInterface
reference and reusing it.
Hope that helps,
Nils
Tiffany wrote:
>
JNDI lookups are expensive timewise. Our question is ... would it be
pratical to lookup all our EJB Home interfaces once at startup and store
these references in a global class accessible to all clients? These home
interfaces then become readily available factories for acquiring instances
of remote interfaces. Is there anything wrong with this picture? Is this a
problem because these home stubs are not reentrant and may be accessed
concurrently by more than one client? Is there a problem with have one home
reference create multiple remote references of an ejb?
Any light that can be shed on this question wouls be appreciated.
Thanks.
tiffany
San Diego--
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