验证文本字段意外结果答案

【问题标题】：validation text field unexpected outcome验证文本字段意外结果
【发布时间】：2019-04-05 10:35:13
【问题描述】：

目前我正在为 java netbeans 编写代码以创建一个正常工作的登录表单。我的代码运行完美，但唯一的问题是我的验证没有按照我想要的方式工作。例如，当我为表单留下用户名文本字段时。它向我显示了输入凭据的提示。但是一旦我按下解雇提示。它提交带有空文本字段的表单。下面是我的代码：

我做错了什么？

   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);
   }

【问题讨论】：

嗯，问题正是您所描述的：尽管值无效，但您继续执行该方法的其余部分。您需要返回或使用else 块。您还需要正确缩进代码，以便阅读并理解其结构。
正确缩进您的代码，以便您更清楚地理解您的代码。然后在你关闭提示后在该行下一个断点，并逐行慢慢调试，以了解你的程序在哪里走错了。

标签： java swing netbeans joptionpane

【解决方案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);
   }

【讨论】：