验证文本字段意外结果

Question

目前我正在研究java netbeans的代码来创建一个正常运行的登录表单。我的代码运行完美，但唯一的问题是我的验证不按照我希望的方式工作。例如，当我离开表单的用户名文本字段时。它向我显示输入凭据的提示。但是一旦我按下那个提示就解雇了。它使用空文本字段提交表单。这是我的代码如下：

我究竟做错了什么？

   try{
        String username;
        username = usernameTxt.getText();
        String password;
        password= new String (passwordTxt.getText());
     if(username.equals("")){
        JOptionPane.showMessageDialog(null,"Please Enter Your Username.");
    }
    if(password.equals("")){
        JOptionPane.showMessageDialog(null,"Please Enter Your Password.");
    }

    String confirmpassword = new String (confirmpassTxt.getText());

    if(password.equals(confirmpassword)){
       confirmpassLab.setText("");
    }
    else {
    confirmpassLab.setText("PASSWORD DOES NOT MATCH.");
    }
        PrintWriter pw = new PrintWriter (new BufferedWriter(new FileWriter("ResidentLoginCredentials.txt",true))); // TRUE is to get all the information from the form to send it into the database. this code is to send the information to the databse 
        pw.println(username); // passing that value to the file 
        pw.println(password); // passing the name value to the database 
        pw.close();
        JOptionPane.showMessageDialog(this,"Your Account Has Been Successfully Registered.","File Message", JOptionPane.INFORMATION_MESSAGE);
        usernameTxt.setText("");
        passwordTxt.setText("");
        this.setVisible(false); // this makes the current form disappear and the new form to open
    residentassignunit ru = new residentassignunit(); // this codes are to redirect user to another form
    ru.setVisible(true);

   }
   catch(IOException e)
   {
        JOptionPane.showMessageDialog(this,"File Not Found","File Error Message Box",JOptionPane.ERROR_MESSAGE);
   }

Answer 1

try{
        String username;
        username = usernameTxt.getText();
        String password;
        password= new String (passwordTxt.getText());

     if(username.equals("")){
        JOptionPane.showMessageDialog(null,"Please Enter Your Username.");
    }else if(password.equals("")){
        JOptionPane.showMessageDialog(null,"Please Enter Your Password.");
    }else if(!password.equals(confirmpassword)){
       confirmpassLab.setText("PASSWORD DOES NOT MATCH.");          
    }else{
       String confirmpassword = "";    

        PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("ResidentLoginCredentials.txt",true))); // TRUE is to get all the information from the form to send it into the database.this code is to send the information to the databse 

        pw.println(username); // passing that value to the file 
        pw.println(password); // passing the name value to the database 
        pw.close();
        JOptionPane.showMessageDialog(this,"Your Account Has Been Successfully Registered.","File Message", JOptionPane.INFORMATION_MESSAGE);
        usernameTxt.setText("");
        passwordTxt.setText("");
        this.setVisible(false); // this makes the current form disappear and the new form to open
    residentassignunit ru = new residentassignunit(); // this codes are to redirect user to another form
    ru.setVisible(true);
  }    
   }
   catch(IOException e)
   {
        JOptionPane.showMessageDialog(this,"File Not Found","File Error Message Box",JOptionPane.ERROR_MESSAGE);
   }