Oracle E-Business Suite uses three OC4J (oacore, oafm & forms) for Java Applications including Forms and HTTP Server for static HTML content.
All these four components are managed (including startup/shutdown) by OPMN (OracleProcess Manager & Notification) 
A. Script to start/stop OPMN in R12 – $ADMIN_SCRIPTS_HOME/ adopmnctl.sh
B. Script to start/stop HTTP Server in R12 – $ADMIN_SCRIPTS_HOME/ adapcctl.sh
C. Script to start/stop oacore OC4J in R12 – $ADMIN_SCRIPTS_HOME/ adoacorectl.sh
D. Script to start/stop oafm OC4J in R12 – $ADMIN_SCRIPTS_HOME/ adoafmctl.sh
E. Script to start/stop forms OC4J in R12 – $ADMIN_SCRIPTS_HOME/ adformsctl.sh