I want to put an SFSB into JNDI. So I generate the SFSB an put it with ctx.bin into the brunch "java/comp/env". But when I want to get it out of it, I always get an CastException when calling narrow. Have sombody done something like that? Can you post some code, please? I want to use the SFSB like an Singleton, a service. I think this is ok in JNDI, because if the application is running on more than one computer, all clients can use the SFSB. If I build up a Singleton, then I only have a "semi-singleton" (always bound to the local jvm).