I normally use this script when i replicate my production database do development or testing environment.
Script:
spool change_password_exe.sql
select 'alter user "'||username||'" identified by your_secrect_password;'
from dba_users
where username not in ('SYS','SYSTEM','DBSNMP',
'AURORA$JIS$UTILITY$','OSE$HTTP$ADMIN',
'OUTLN','PUBLIC','WEBSYS','AURORA$ORB$UNAUTHENTICATED','TRACESVR')
/
select 'alter user "'||username||'" account unlock ;'
from dba_users
where username not in ('SYS','SYSTEM','DBSNMP',
'AURORA$JIS$UTILITY$','OSE$HTTP$ADMIN',
'OUTLN','PUBLIC','WEBSYS','AURORA$ORB$UNAUTHENTICATED','TRACESVR')
/
spool off
set echo on
@change_password_exe.sql
set define on