通过将登录代码与JavaGUI链接来创建登录

我一直在尝试将我的登录代码与我创建的java gui链接，但是在运行它时遇到了问题。 1） 代码不读取我创建的文本文件 2） 当我按下gui的登录时，它什么也不做。我希望它检查输入的用户名和密码与文本文件中的用户名和密码

请帮助我，我已经检查了其他解决方案，但我找不到任何与我的问题相关的解决方案。 我认为我没有把代码链接好，所以如果有人能帮上忙，那就太好了

头等舱： 导入java.awt.EventQueue

    import javax.swing.JFrame;
    import javax.swing.JOptionPane;
    import javax.swing.JTextField;
    import javax.swing.JPasswordField;
    import javax.swing.JLabel;
    import javax.swing.JButton;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.util.Scanner;


    public class Login extends JFrame{


public JFrame frame;
public JPasswordField passwordField;
public JTextField textField;
public JButton blogin;
public JButton btnNewUser;

/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                Login window = new Login();
                window.frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the application.
 */
public Login() {
    initialize();
}

/**
 * Initialize the contents of the frame.
 */
public void initialize() {
    frame = new JFrame();
    frame.getContentPane().setLayout(null);

    passwordField = new JPasswordField();
    passwordField.setBounds(90, 114, 105, 22);
    frame.getContentPane().add(passwordField);

    textField = new JTextField();
    textField.setBounds(90, 79, 105, 22);
    frame.getContentPane().add(textField);
    textField.setColumns(10);

    JLabel lblUsername = new JLabel("Username");
    lblUsername.setBounds(220, 82, 76, 16);
    frame.getContentPane().add(lblUsername);

    JLabel lblPassword = new JLabel("Password");
    lblPassword.setBounds(220, 117, 66, 16);
    frame.getContentPane().add(lblPassword);

    JButton blogin = new JButton("Login");
    blogin.setBounds(144, 158, 97, 25);
    frame.getContentPane().add(blogin);

    JButton btnNewUser = new JButton("New User ?");
    btnNewUser.setBounds(144, 196, 97, 25);
    frame.getContentPane().add(btnNewUser);


    frame.add(blogin);
    frame.add(passwordField);
    frame.add(textField);
}
Logincode lc = new Logincode();
public void actionlogin(){
    blogin.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent ae){

        Scanner sc;
        try {
            sc = new Scanner(new File("Logincode.txt"));
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Scanner scan = new Scanner(new File("Logincode.txt"));
        Scanner keyboard = new Scanner (System.in);

        String inpUser = keyboard.nextLine();
        inpUser = textField.getText();
        String inpPass = keyboard.nextLine();
        inpPass = passwordField.getText();// gets input from user

        String user = scan.nextLine();
        String pass = scan.nextLine(); // looks at selected file in scan

        if (inpUser.equals(user)&& inpPass.equals(pass)){
            System.out.print("your login message");
        }else {

    JOptionPane.showMessageDialog(null,"Wrong Password / Username");
        }
        }
        });
        }
        }

这是第二节课：

    import java.util.Scanner; // I use scanner because it's easier for me.
    import java.io.File;
    import java.io.FileNotFoundException;

    public class Logincode{
    public static void run() throws FileNotFoundException {
Scanner scan = new Scanner (new File("Logincode.txt"));
Scanner keyboard = new Scanner (System.in);

String inpUser = keyboard.nextLine();
String inpPass = keyboard.nextLine(); // gets input from user

String user = scan.nextLine();
String pass = scan.nextLine(); // looks at selected file in scan

if (inpUser.equals(user)&& inpPass.equals(pass)){
    System.out.print("your login message");
} else {
    System.out.print("your error message");
}

    }

public static void main(String[] args){

    try {
        run();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


}







    }

---

好的，有太多的错误需要记住并列出，但这里有几个：

其中一个错误是在类已经扩展了JFrame的情况下创建了JFrame，实际上使其成为JFrame

您也只在

actionlogin（）

方法中添加了登录按钮的操作侦听器，但从未调用过该方法

有多个扫描仪指向同一个文件

您尝试从控制台和文本字段读取输入，然后将它们分配给同一个变量，两次

您创建了第二个类，该类具有与“main”类相同的功能，并且都有main方法

我留下了一些你的代码，这样你可以看到一些错误和额外的花絮，你放进去，这是不需要的。我也没有修复您的框架，因为在构建GUI时，有许多宝贵的经验教训只能通过反复尝试才能学到

代码：

希望这有帮助

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JTextField;


public class Login extends JFrame{

   //public JFrame frame; //Extends JFrame already so 'this' IS a frame
   public JPasswordField passwordField;
   public JTextField textField;
   public JButton blogin;
   public JButton btnNewUser;

   /**
    * Launch the application.
    */
   public static void main(String[] args) {
       EventQueue.invokeLater(new Runnable() {
           public void run() {
               try {
                   Login window = new Login();
                   window.setVisible(true);
               } catch (Exception e) {
                   e.printStackTrace();
               }
           }
       });
   }

   /**
    * Create the application.
    */
   public Login() {
       initialize();
   }

   /**
    * Initialize the contents of the frame.
    */
   public void initialize() {

     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //DO NOT forget this, the instance will continue to run if not.
     setLayout(null);

     setSize(350,300); // only added so I didn't have to expand window as often

     passwordField = new JPasswordField();
     passwordField.setBounds(90, 114, 105, 22);
     add(passwordField);

     textField = new JTextField();
     textField.setBounds(90, 79, 105, 22);
     add(textField);
     textField.setColumns(10);

     JLabel lblUsername = new JLabel("Username");
     lblUsername.setBounds(220, 82, 76, 16);
     add(lblUsername);

     JLabel lblPassword = new JLabel("Password");
     lblPassword.setBounds(220, 117, 66, 16);
     add(lblPassword);

     JButton blogin = new JButton("Login");
     blogin.setBounds(144, 158, 97, 25);
     blogin.addActionListener(new ActionListener() { //moved from actionlogin()
         public void actionPerformed(ActionEvent ae){
            actionlogin();
         }
     });

     add(blogin);

     JButton btnNewUser = new JButton("New User ?");
     btnNewUser.setBounds(144, 196, 97, 25);
     add(btnNewUser);        

     add(blogin);
     add(passwordField);
     add(textField);
   }

   //Logincode lc = new Logincode(); Don't know why the second class was created or needed here.

   public void actionlogin(){

        //Scanner sc; not used
        Scanner scan=null;

        try {
            //sc = new Scanner(new File("Logincode.txt")); not used 
            scan = new Scanner(new File("Change to the path where your file is located ofcourse")); //make sure to add your path

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        //Scanner keyboard = new Scanner (System.in);       

        //String inpUser = keyboard.nextLine();
        String inpUser;
        inpUser = textField.getText();

        //String inpPass = keyboard.nextLine();
        String inpPass;
        inpPass = passwordField.getText();// gets input from user

        String user="";
        if(scan.hasNextLine()) //added to check if there is another line to read
           user = scan.nextLine();            

        String pass="";
        if(scan.hasNextLine())
           pass = scan.nextLine(); // looks at selected file in scan

            if (inpUser.equals(user)&& inpPass.equals(pass)){
                System.out.print("your login message");
            }else {
                JOptionPane.showMessageDialog(null,"Wrong Password / Username");
            }
   }       

}