toplink postgres default

Hi.
Java NetBeans 5.5
Database: PostgreSQL  Version: 8.2


I have field in datatable:

   sysdate timestamp without time zone NOT NULL DEFAULT now(),


How to use DEFAULT value from database in Java entity class.
My field mapping is:

     @[EMAIL PROTECTED]
(name = "sysdate", nullable = false,insertable =
false,updatable=false)
     @[EMAIL PROTECTED]
(Tem****alType.TIMESTAMP)
     private Date sysdate;

I try to use @[EMAIL PROTECTED]
 annotation but not work.