Invoking Web Services From a Java Client

Question

I have a simple web app that runs inside Tomcat. I need to call a web service from this web app and I'm not sure how to go about it. It seems there are two methods depending on whether you are using a managed or unmanaged environment:

JNDI service lookup (managed)

and

JAX-RPC ServiceFactory (unmanaged)

...So which technique should I use?

Answer 1

If it is a web-service, why not use apache's httpclient?