If you are maintaining Oracle Application Server 10g Release 3 (10g AS R3) or Oracle Apps R12 (which uses 10g AS R3 as tech. stack) and you wish to reset OC4JADMIN password here are few pointers

1. oc4jadmin is superuser account created during installation (Installer prompts for oc4jadmin password if this is 10g AS R3)

2. This password is stored in encrypted format in file  system-jazn-data.xml $ORACLE_HOME/j2ee/home/config (In R12 there are two ORACLE_HOME in middle tier one for Web Server and another for Forms (third one is on database tier) and configuration file is under $ORA_CONFIG_HOME/ 10.1.3/ j2ee/ [oc4j_name]/ config). There are three OC4J in R12 so change in all three oc4j config file i.e. oacore, forms, and oafm

3. You can reset this password using enterprise console http:// machine : http_port/em ,    follow exact steps from here

4. If you can’t remember original OC4JADMIN password you can reset it by using documentation here

5. If your 10g AS R3 or R12 is configured to use Oracle Identity Management (OID) then you have to update OC4JADMIN password using /oiddas screen (in OID).

-
Related
466246.1  How To Reset The Password Of The oc4jadmin Account For Enterprise Manager
576587.1  How to change the OC4Jadmin Password
556031.1  How To Have The Password In Clear Text In Jazn-data.xml?
403678.1  How To Change The Passwords For BPELADMIN / OC4JADMIN / SOA Suite
-

Question for Readers ?
What is default oc4jadmin password in R12 ?