Username / Password Validation from a Text File

Lab1Frame.java

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.util.Scanner;

public class Lab1Frame extends JFrame
 {
  private static final int FRAME_WIDTH = 250;
  private static final int FRAME_HEIGHT = 200;
  private File userData;
  static JTextField userNameField;
  static JTextField passwordField;
 
 public Lab1Frame() throws FileNotFoundException
 {
 createComponents();
 setSize(FRAME_WIDTH, FRAME_HEIGHT);
 }

 private void createComponents() throws FileNotFoundException
 {
    userNameField = new JTextField(10);
    passwordField = new JTextField(10);
    
    JLabel userNameLabel = new JLabel("User Name");
    JLabel passwordLabel = new JLabel("Password");
    
    JButton loginButton = new JButton("Login");
    JButton exitButton = new JButton("Exit");
    
    JPanel panel = new JPanel();
    panel.add(userNameField);
    panel.add(userNameLabel);
    panel.add(passwordField);
    panel.add(passwordLabel);
    panel.add(loginButton);
    panel.add(exitButton);
    add(panel);

 ActionListener exitListener = new ClickListener1();
 ActionListener loginListener = new ClickListener2();
 exitButton.addActionListener(exitListener);
 loginButton.addActionListener(loginListener);
 }
 public class ClickListener1 implements ActionListener 
 {

   public void actionPerformed(ActionEvent event)
   {
     System.exit(0);
   }
  }
  public class ClickListener2 implements ActionListener 
 {

   public void actionPerformed(ActionEvent event)
   {
     File inputFile = new File("USERDATA.txt");
     
     String userNameInput = userNameField.getText();
     String passwordInput = passwordField.getText();
     
     try {
            Scanner in = new Scanner(new File("USERDATA.txt"));
            while (in.hasNextLine())
            {
              String s = in.nextLine();  
              String[] sArray = s.split(",");
              
              System.out.println(sArray[0]); //Just to verify that file is being read
              System.out.println(sArray[1]);

              
              if (userNameInput == sArray[0] && passwordInput == sArray[1])
              {
                JOptionPane.showMessageDialog(null,
                    "Login Successful", "Success",
                    JOptionPane.INFORMATION_MESSAGE);
              }
              else
              {
                JOptionPane.showMessageDialog(null,
                    "Invalid Username / Password Combo", "Error",
                    JOptionPane.ERROR_MESSAGE);
              }
            }
            
            in.close();
            
        } catch (FileNotFoundException e) {
            JOptionPane.showMessageDialog(null,
                    "User Database Not Found", "Error",
                    JOptionPane.ERROR_MESSAGE);
        }
    
   }
  }
}

Lab1Viewer.java

import javax.swing.JFrame;
import java.io.*;

 public class Lab1Viewer
{
 public static void main(String[] args) throws FileNotFoundException
 {
 JFrame frame = new Lab1Frame();
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 frame.setVisible(true);
 }
 }

USERDATA.txt

CharlieBrown,kdc*iJWw
Snoppy,3KnEgof9%
Linus,$R$ARo1g
PeppermintPatty,PD9wtik09+
Lucy,J!nyMdfp@7x

This helped me a lot, thanks man !!

the file can't be read, why is that?

it reads only the first line of text file

It will always display the Invalid Username/Password Combo it cannot read the USERDATA

I was able to get it to work successfully by putting the USERDATA.txt file directly into the target folder on the main project. Thanks for this works great!

instead of using ==
use userNameInput.equals(sArray[0] && passwordInput.equals(sArray[1]))
this will work