在這里我從文本字段中獲取值private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) {                                             String userName = txtUserName.getText();    char[] passwordArray = txtPassword.getPassword();    String password = " ";    for(int i = 0; i < passwordArray.length; i++){        password = password + passwordArray[i];    }    int numberOfRecords = 0;    if(userName.equals("") || password.equals("")){        JOptionPane.showMessageDialog(this, "Please fill the form properly:");    }else{        System.out.println("i am here");        numberOfRecords = userServices.tryLogin(userName, password);        System.out.println("after number of records");        if(numberOfRecords == 1){            this.dispose();            mainForm.setVisible(true);        }else{            JOptionPane.showMessageDialog(this, "Sorry user name or password is incorrect:");        }    }    txtUserName.setText(" ");    txtPassword.setText("");}這是我的嘗試登錄方法public int tryLogin(String userName, String password) {    int numberOfRecords = 0;    SQLQueryUtil sql = new SQLQueryUtil();   sql.connect(false);   String query = "SELECT COUNT(*) AS `number_of_records` FROM `user` "            + "WHERE `userName`='" + userName + "' AND `password`='" + password + "';";    System.out.println(query);    ResultSet resultSet;    try{       resultSet = sql.executeQuery(query);        resultSet.isBeforeFirst();       numberOfRecords = resultSet.getRow();         System.out.println("number of Records =" + numberOfRecords);    } catch (Exception ex) {        ex.printStackTrace();    } finally{        sql.disconnect();    }    System.out.println("i am here also..............................");    return numberOfRecords;}當我點擊登錄按鈕時，它顯示以下結果驅動程序加載連接建立語句創建選擇計數（*）number_of_records從user哪里userName=''和password=''；記錄數 =0