java - ActionListener 逻辑错误 (Java)

Question

我的 updateButtonResults 按钮有一个小问题。我有 JOptionPane 消息对话框，当用户更新 First Name、Last Name、E-mail 和 Sign-up date 这四个字段时，这些对话框被编程为弹出。我的问题是所有 4 条消息都会弹出，即使我只更新了一个字段。示例:我更新客户的姓氏，消息对话框将按此顺序弹出(名字、姓氏、电子邮件、注册日期)。

这是我的代码

//method for buttons on 'resultFrame'
public void BtnAction3() 
{                        
  updateButtonResults.addActionListener(
        new ActionListener()
        {
           //method for events that will be performed when updateButton is pressed
           public void actionPerformed(ActionEvent e) 
           {
              //instanciates variables to text in textfields
              String fname = fNameTextBoxResults.getText();
              String lname = lNameTextBoxResults.getText();
              String email = eMailTextBoxResults.getText();
              String signUpDate = signUpTextBoxResults.getText();

              try
              {
                 //statement that checks to make sure user enters only letters
                 if(fname.matches("[a-zA-Z]+"))
                 {
                    //updates 'Fname' field in db to text that user inputted in 'fname' textfield
                    rs2.updateString("Fname", fname);
                    JOptionPane.showMessageDialog(null, "Customer first name been updated!");
                 }

                 //statement that prompts user if they enter something other letters
                 else
                 {
                    JOptionPane.showMessageDialog(null, "Please enter first name in correct format!");
                    fNameTextBoxResults.setText("");
                 }

                 //statement that checks to make sure user enters only letters
                 if(lname.matches("[a-zA-Z]+"))
                 {   
                    //updates 'Lname' field in db to text that user inputted in 'lname' textfield                      
                    rs2.updateString("Lname", lname);
                    JOptionPane.showMessageDialog(null, "Customer last name been updated!");
                 }

                 //statement that prompts user if they enter something other letters
                 else
                 {
                    JOptionPane.showMessageDialog(null, "Please enter last name in correct format!");
                    lNameTextBoxResults.setText("");
                 }

                 //statement and actions if user enters a '.'
                 if(email.contains("."))
                 {  
                    //gets last period in "email"
                    int emailDotCheck = email.lastIndexOf(".");

                    //substring to period in variable "emailDotCheck"
                    String extensionCheck = email.substring(emailDotCheck);

                    //statement and actions if user doesn't enter email correctly           
                    if(!email.contains("@") || !extensionCheck.matches("\\.[a-z]{3}"))
                    {
                       JOptionPane.showMessageDialog(null, "Please enter email in correct format!");
                       eMailTextBoxResults.setText("");
                    }                   

                    //statement and actions if user enters email correctly
                    else
                    {
                       //updates 'E-mail' field in db to text that user inputted in 'email' textfield
                       rs2.updateString("E_mail", email);
                       JOptionPane.showMessageDialog(null, "Customer E-mail been updated!");
                    }
                 }

                 //action if user doesnt enter email correctly
                 else
                 {
                    JOptionPane.showMessageDialog(null, "Please enter email in correct format!");
                    eMailTextBoxResults.setText("");
                 }

                 //instance variables for 'signUpDate'
                 int month = 100;
                 int day = 100;
                 int year = 10000;

                 if(signUpDate.matches("\\d{2}/\\d{2}/\\d{4}"))
                 {
                    //instance variables
                    String monthStr = signUpDate.substring(0,2);
                    String dayStr = signUpDate.substring(3,5);
                    String yearStr = signUpDate.substring(6);

                    //parsing intstance variables to Integers
                    month = Integer.parseInt(monthStr);
                    day = Integer.parseInt(dayStr);
                    year = Integer.parseInt(yearStr);

                    //statement and actions if user doesn't follow correct format
                    if(month > 12 || day > 31 || year > 2100)
                    {
                       JOptionPane.showMessageDialog(null, "Please enter date in correct format! (dd/MM/yyyy)");
                       signUpTextBoxResults.setText("");
                    }

                    //statements and actions if user enters date correctly
                    else
                    {
                       //updates 'Sign-up date' field in db to text that user inputted in 'signUpDate' textfield
                       rs2.updateString("Sign_up_date", signUpDate);
                       JOptionPane.showMessageDialog(null, "Customer Sign-up date been updated!");
                    } 
                 }

                 //statement and actions if user doesn't follow correct format           
                 else 
                 {
                    JOptionPane.showMessageDialog(null, "Please enter date in correct format! (dd/MM/yyyy)");
                    signUpTextBoxResults.setText("");
                 }

                 //updates row in db
                 rs2.updateRow();
                 //JOptionPane.showMessageDialog(null, "Customer has been updated!");

              }

              catch(Exception ex)
              {

              }          
           }          
        });

我正在尝试学习遍历我的代码，我已经对其进行了调试，但仍然无法找出逻辑错误。

感谢您的帮助

Answer 1

您有四个文本字段:

fNameTextBoxResults
lNameTextBoxResults
eMailTextBoxResults
signUpTextBoxResults

与其尝试一次验证所有输入，不如尝试使这段代码更模块化。分离属于特定字段的所有逻辑，并将其作为 ActionListener 添加到该字段。示例:

 fNameTextBoxResults.addActionListener(
    new ActionListener()
    {
       public void actionPerformed(ActionEvent e) 
       {
             //statement that checks to make sure user enters only letters
             if(fname.matches("[a-zA-Z]+"))
             {
                //updates 'Fname' field in db to text that user inputted in 'fname' textfield
                rs2.updateString("Fname", fname);
                JOptionPane.showMessageDialog(null, "Customer first name been updated!");
             }

             //statement that prompts user if they enter something other letters
             else
             {
                JOptionPane.showMessageDialog(null, "Please enter first name in correct format!");
                fNameTextBoxResults.setText("");
             }
       }
    });

冲洗并重复其他三个字段。如果您需要完成某些类型的操作，则可以使用 updateButtonResults 来完成。否则，该按钮完全没有必要。