public boolean isLogin(String user, String pass) throws Exception {

        PreparedStatement pr = null;
        ResultSet rs = null;

        String sql = "SELECT * FROM login where username  = ? and password = ?";

        try {
            pr = this.connection.prepareStatement(sql);
            pr.setString(1, user);
            pr.setString(2, pass);
            rs = pr.executeQuery();
            boolean boll;

            if (rs.next()) {
                return true;
            }
            return false;
        }
        catch(SQLException ex){
            return false;
        }
finally{
            pr.close();
            rs.close();
        }
    }