You need to place the "jndi.properties" file in the client classpath(the place from where you are executing your standalone java client). Sample jndi.properties will contain something like the following:
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces java.naming.provider.url=jnp://localhost:1099
It sounds to be better now.
One more question where can I find the specification related to this "jndi.properties" (format, use,...).
Many thanks for your help.