public List<PacketInterceptor> getInterceptors() {
        return Collections.unmodifiableList(globalInterceptors);
    }
Returns an unmodifiable list of global packet interceptors. Global
interceptors are applied to all packets read and sent by the server.

@return an unmodifiable list of the global packet interceptors.
xmppserver/src/main/java/org/jivesoftware/openfire/interceptor/InterceptorManager.java