No I created a really simple programmatic callback handler that writes out the arguments to public void handle(Callback[] callbacks). There is only one line printed on the output. This means that the callback handler is only called once.
The output is
handle: [javax.security.auth.callback.NameCallback_at_faa9e2, javax.security.auth.callback.PasswordCallback_at_a7758e]
May 17, 2008 1:02:36 AM com.sun.enterprise.appclient.MainWithModuleSupport <init>
WARNING: ACC003: Application threw an exception.
com.sun.enterprise.InjectionException: Exception attempting to inject Resolved Ejb-Ref authea.AuthApplication/authSessionBeanBean_at_jndi: authea.ejb.AuthSessionBeanRemote - > AuthSessionBeanBean into class authea.AuthApplication
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