The OC4J_SOA container never stops gracefully and the stop log from the default_group~<oc4j_container_name>~default_group~1.log file shows that it always stops on deactivation of the endpoint for ESB adapters.
This is due to the fact that the default stop timeout for OC4J, as specified in the
opmn.xml file, is 120, out of which most of the time is consumed by the initial process, that is, BPEL shutdown.
So, ESB does not have much time for the shutdown, so the Oracle Process Management Notification (OPMN) shuts it down forcibly. You can solve this problem by increasing the stop timeout for OC4J in the opmn.xml file.