合并/分支实践(Merging/branching practices)

            PreparedStatement stmt = getCon().prepareStatement("SELECT * FROM MesLib.tblSchoolRecordsr where strstudName = ? and strDoubleCheckCode = ? and (lngstudID NOT LIKE '-[^0-9]') ");
            stmt.setString(1, studName);
            stmt.setString(2, DoubleCheck);
            stmt.setString(3, lngstudID);
 
 你的SQL中有 两个问号（？） 。 所以这个查询只需要两个参数。 但是你要设置三个参数 。 因此发生3个超出范围异常的索引 。 
 
 要避免此异常，请删除此行。 根据你的sql原因这行（下面）是不必要的 
 
            stmt.setString(3, lngstudID); 

            PreparedStatement stmt = getCon().prepareStatement("SELECT * FROM MesLib.tblSchoolRecordsr where strstudName = ? and strDoubleCheckCode = ? and (lngstudID NOT LIKE '-[^0-9]') ");
            stmt.setString(1, studName);
            stmt.setString(2, DoubleCheck);
            stmt.setString(3, lngstudID);
 
Here two question marks (?) in your sql. So this query wants only two parameter. But you are setting three parameters. Thus index of 3 out of range exception occurs.
 
To avoid this exception remove this line. Cause according to your sql this line (below) is unnecessary
 
            stmt.setString(3, lngstudID);