What to do with those invalid JAVA CLASS object type objects in SYS prior to the upgrade the oracle db from 10g to 11g?
From this blog you can try this on development first...

SQL> spool resolve.sql;

SQL> select ‘alter java class “‘||object_name||’” resolve;’
  2  from user_objects
  3  where object_type like ‘%JAVA%’;

SQL> spool off;

SQL> @resolve 

The clean sweep approach would be to remove and reinstall the java JVM

The Java VM is created and populated with system classes during CREATE OR REPLACE JAVA SYSTEM command.  Run rmjvm.sql to remove the JVM first, then bounce the database then initjvm.sql

I repeat, these should be tried on your development stack first!