YD@MYDB.MU> CREATE or replace JAVA SOURCE
  2  NAMED "YdTimestamp"
  3  AS
  4  import java.lang.String;
  5  import java.sql.Timestamp;
  6
  7  public class YdTimestamp
  8  {
  9    public static String getTimestamp()
 10    {
 11     return (new
 12     Timestamp(System.currentTimeMillis())).toString();
 13    }
 14* };
YD@MYDB.MU> /

Java created.

YD@MYDB.MU> create or replace function my_timestamp return varchar2
  2  AS LANGUAGE JAVA
  3  NAME 'YdTimestamp.getTimestamp() return java.lang.String';
  4  /

Function created.

YD@MYDB.MU> select my_timestamp, to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual;

MY_TIMESTAMP
--------------------------------------------------------------------------------
TO_CHAR(SYSDATE,'YY
-------------------
2004-03-23 05:33:41.062
2004-03-23 09:33:32


YD@MYDB.MU>