Use 'default' keyword in call string while calling stored proc?

Question

I am calling following sql server stored procedure from java code using my jdbc driver for sql server: CREATE PROCEDURE test_findTbInfo (
@paramIn_Str varchar(10),
@paramOut_Int int OUT,
@paramIn_Int int = 20
AS
begin
set @paramOut_Int = @paramIn_Int * 100
end
If I make a call like this:
CallableStatement cs = conn.prepareCall(" { call test_findTbInfo(? , , ? ) }");
cs.setString(1, "test_tab");
cs.setInt(2, 4);
cs.execute();
It works without any error. But this is not a right behavior. !! The second parameter as you see is passed like an optional parameter. But in stored proc it is NOT an optional param and so if the value not passed it should fail...
Now if I change the code to
CallableStatement cs = conn.prepareCall(" { call test_findTbInfo(? , default, ? ) }");
it works correctly. Gives error that "Procedure 'test_findTbInfo' expects parameter '@paramOut_Int', which was not supplied." which is correct.
So is it a normal practice to use 'default' keyword while calling sql server stored procedures having optional parameters in jdbc ????
Anyone knows ??? As far as I know "call test_findTbInfo(? , , ? )" works fine except in some cases and also it forces users to put all optional parameters at the end of parameter list in stored proc.
Please let me know whether I should go with 'default' throuout for sql server stored proc while calling using my jdbc driver.
Amit

Answer 1

{?= call <procedure-name>[<arg1>,<arg2>, ...]}The question mark in the above is the result parameter
that must be registered.
That is not the same as an OUT argument.Yes that is true. The result value and OUT parameters are different but they both MUST be registered as per jdbc API
"The type of all OUT parameters must be registered prior to executing the stored procedure; their values are retrieved after execution via the get methods provided here."
Anyway, my original question still stays as it was. If there are some optional IN parameters in stored procedure
e.g.
PROCEDURE test_findTbInfo (
@paramIn_Int int = 20,
@paramOut_Int int OUT
how do you call this?
CallableStatement cs = conn.prepareCall(" { call test_findTbInfo( , ? ) }");
cs.registerOutParameter(1, Types.INTEGER);
cs.execute();
or
CallableStatement cs = conn.prepareCall(" { call test_findTbInfo(default, ? ) }");
Also note that I am intending to use ONLY sql server driver for this.
The first as well second seem to work. Except that second way is seems reliable. I just wanted a second opinion on that...
Amit