SQL & PL/SQL

I have a table that contains information about software. One of its columns is
VERSION varchar2(32) not null
The problem is that when I select from this table comparison must be something other the lexicographic. I.e. 1.11 < 11.1 or 2.0 > 2.0beta2.
So, I created the Java class Version that implements Comparable interface. Its method compareTo encapsulate all logic. I then loaded this class using loadjava utility and I am trying to test it.
I created
a) datatype using
create or replace type VERSION as object
external name 'com.mycompany.myproject.Version' language java using
SQLData (VALUE VARCHAR2(32));
b) table containing just two columns
create table TEST (TITLE varchar2(30) not null, VRSN VERSION);
I got no errors and can actually successfully insert data into the table.
However, if I am trying to retrieve data I am getting either empty value if no criteria specified, otherwise I am getting an error:
ORA-22950: cannot ORDER objects without MAP or ORDER method
I searched documentation and it mention these methods for UDTs but I did not find a single example.
Can someone point me to the right place or share a working example or, if you have an alternate idea how to achive the same result, I'd be glad to hear it too.