Info: Data source is: opss-DBDS [EL Severe]: 2017-12-19 09:29:08.267--ServerSession(703395433)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.1.v20111018-r10243): org.eclipse.persistence.exceptions.DatabaseException Internal Exception: java.sql.SQLException: ORA-01017: invalid username/password; logon denied

Info: Data source is: opss-DBDS [EL Severe]: 2017-12-19 09:29:08.267--ServerSession(703395433)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.1.v20111018-r10243): org.eclipse.persistence.exceptions.DatabaseException Internal Exception: java.sql.SQLException: ORA-01017: invalid username/password; logon denied

                 Issue:-In my case OIM&OAM schema password got expired and schemas
                            passwords are reseted to old password.
                            So i tried starting Weblogic admin server i have started
                            facing below issue       
  
 Info: Data source is: opss-DBDS [EL Severe]: 2017-12-19 09:29:08.267-ServerSession(703395433)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.1.v20111018-r10243): org.eclipse.persistence.exceptions.DatabaseException Internal Exception: java.sql.SQLException: ORA-01017: invalid username/password; logon denied                                   

Troubleshooting and to resolving following above issue
1.Go to following location
        In  my case:-/u04/Oracle_IDM1/common/bin
        And run ./wlst.sh
2.Once you hit ./wlst.sh you will be connected wls:/offline>
          run following command :
modifyBootStrapCredential(jpsConfigFile="/u04/user_projects/domains/OAMDomain/config/fmwconfig/jps-config.xml",username="PROD_OPSS",password="XXXXXX")

3.Run above command and hit enter

4.Once above command is executed successfully you should be able to
    start Admin and Managed servers successfully