I am not familiar with the run-time structure of the JBoss environment, but in general, the relevant system properties for truststore and keystore are only read once per JVM invocation; changing them has no effect after they are read. The only other methods I know of for customizing these are explained in the JSSE Reference Guide.
Can you please let me know how you had successfully setup client-side trust-store in JBOSS ?
I have the similar scenario. My JBOSS server connects to other servers via HTTPS and now one such URL it cannot connect. So, I have obtained the public cert from the server into a client.truststore. Now, this client.truststore should be installed in the JBOSS so that it trusts the server it connects to.
hence, please let me know how you made it work successfully.