Java Database Connectivity (JDBC)

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