could disable java
Though it is enabled by default, I remember disabling it on my last installs since the app that I use oracle with (vCenter) doesn't need it.
SQL> select comp_name from dba_registry;
COMP_NAME
--------------------------------------------------------------------------------
Oracle Enterprise Manager
Oracle XML Database
Oracle Text
Oracle Workspace Manager
Oracle Database Catalog Views
Oracle Database Packages and Types
6 rows selected.
You can probably do it on the fly(as in don't have to reinstall) as well assuming you don't need it:
http://fast-dba.blogspot.com/2014/04/how-to-remove-unwanted-components-from.html