How to arrange/sort string in Oracle SQL - 11g

I have a string an string "ADBDkK" and I need to sort it as "ABDDKk", like Arrays.sort() in java. I know it can be done by using PL/SQL but I need of this in Oracle SQL statement.

Input:

ADBDkK
ZXYABC

Output:

ABDDKk
ABCXYZ

SQL Fiddle

Oracle 11g R2 Schema Setup:

CREATE TABLE test ( value ) AS
SELECT 'ADBDkK' FROM DUAL UNION ALL
SELECT 'ZXYABC' FROM DUAL;

Query 1:

WITH chars ( id, value, ch, lvl ) AS (
  SELECT ROWNUM, value, SUBSTR( value, 1, 1 ), 1
  FROM   test
UNION ALL
  SELECT id, value, SUBSTR( value, lvl+1, 1 ), lvl+1
  FROM   chars
  WHERE  lvl < LENGTH( value )
)
SELECT LISTAGG( ch ) WITHIN GROUP ( ORDER BY ch ) AS value
FROM   chars
GROUP BY id
ORDER BY id

Results:

|  VALUE |
|--------|
| ABDDKk |
| ABCXYZ |

Query 2:

SELECT LISTAGG( COLUMN_VALUE )
         WITHIN GROUP ( ORDER BY COLUMN_VALUE ) AS value
FROM   (
  SELECT value,
         ROWNUM AS id
  FROM test
) t
CROSS JOIN
TABLE(
  CAST(
    MULTISET(
      SELECT SUBSTR( t.value, LEVEL, 1 )
      FROM   DUAL
      CONNECT BY LEVEL <= LENGTH( t.value )
    )
    AS SYS.ODCIVARCHAR2LIST
  )
) c
GROUP BY t.id
ORDER BY t.id

Results:

|  VALUE |
|--------|
| ABDDKk |
| ABCXYZ |