Re: JNDI searches

From:
Tom Anderson <twic@urchin.earth.li>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 9 Apr 2010 00:53:39 +0100
Message-ID:
<alpine.DEB.1.10.1004090046360.2090@urchin.earth.li>
On Thu, 8 Apr 2010, Tim Slattery wrote:

Tom Anderson <twic@urchin.earth.li> wrote:

The Tomcat form is what the standard specifies. If you use that in
WebLogic and JBoss, does it work?


Don't know about JBoss (that was a while ago), but it does not work in
Weblogic.


Okay, having dug into this a bit, i think the rule is that java:comp/env
has to be visible *from a J2EE component*, which i suspect in practice
means from an EJB. It's basically a private environment area that
surrounds each component - each component actually has a *different*
comp/env. I would guess, then, that you're making your lookups from
outside a component - from code somewhere in the region of the servlets,
perhaps? In that case, there is no proper comp/env defined. Exactly where
in the JNDI namespace your resources are bound is, inexplicably, not
specified, and containers can do what they like. Tomcat makes it look the
same as if the lookup came from a component, WebLogic doesn't.

I haven't found a good solution for this. Most of the suggestions are
along the lines of this:

If not, er, well, yes. Define a server-dependent JNDI name prefix and pass
it in as an env-entry or system property, perhaps?


No idea of that.


public class JNDILookupHelper {
  public static Object lookup(String name) throws some exceptions {
  String prefix = System.getProperty("jndi.prefix", "");
  String fullName = prefix + name;
  InitialContext ic = new InitialContext();
  return ic.lookup(fullName);
  }
}

Then apply -Djndi.prefix= as needed.

tom

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