Update not journalized file

Hi,

I have a Java program run on AS400 using native JDBC driver.  I have no
problems to insert, delete or update any tables in DB2 database on AS400,
but when Java program inserts data from DB2 table into a flat file on AS400
library(which is not journalized), the error message says the file is not
journalized, that makes sense.  But I can do the same insert SQL statement
from Operation Navigator's SQL Editor.  I thought that may be autoCommit was
not set up as true, so I specifically set the autoCommit as true in program.
It still failed.  In this case, I do not need the file be journalized in
order to rollback.

I am not quite sure why it is OK to run SQL statement directly, but failed
in Java program?  Any help??

Thanks,

Wayne