Refcursor class not found

hello everybody,

I have created a function to display the rows in a table. The function is
returning the refcursor. I am calling the refcursor in Callable Statement, but
i am getting No class found for refcursor. I have seen these queries earlier in
this forum.

I am using postgresql 7.3.4 and pg73jdbc3.jar.

As per the solutions given for earlier queries i tried to give getString(1), but
i am getting null value.

i am attaching the code along with this mail.

This is my pl/pgsql

CREATE or REPLACE FUNCTION displayall() RETURNS refcursor AS '
DECLARE
cursor1 cursor for select pageid,keyword from Maintable;

BEGIN
    open cursor1;
    return cursor1;
END;

'language 'plpgsql';

My jdbc code is

con.setAutoCommit(false);
CallableStatement cstmt2=null;
cstmt2=con.prepareCall("{? = call displayall()}");
cstmt2.registerOutParameter(1,Types.OTHER);
cstmt2.executeUpdate();
ResultSet rs2=(ResultSet)cstmt2.getObject(1);

i am getting No class found for refcursor and the error is pointing to
cstmt2.executeUpdate() line.

I also tried to use

con.setAutoCommit(false);
CallableStatement cstmt2=null;
cstmt2=con.prepareCall("{? = call displayall()}");
cstmt2.registerOutParameter(1,Types.OTHER);
String test=cstmt2.getString(1);

But test is pointing to null.

Can anyone please help me in solving this problem. I need to sort out this issue
at the earliest as i need to use Callable Statement in JDBC and also pl/pgsql.

Reply awaited.

Regards,
deepthi