Why doesn't .equals() compare these strings?

Question

I have txt file called samplename, in that file there are 3 lines values:

 samplename
 samplepassword
 %%%%%%%%%%%%%%%%%

The Programm is about a login-register system. When I type

 samplename

in the first JTextField and

  samplepassword +

in the second JTextField and press the login button, it supposed to check if I have such account, if it has the right username&password. The Programm reads the things in, just it cant compare it to the the JTextFields. What am i doing Wrong?!?:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;

import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JTextField;

public class SomeClass
{
  public JButton loginButton;

  public JTextField login_username;

  public JTextField login_password;

  String check = null;

  String check2 = null;

  public static void main(String[] args)
  {
    SomeClass someClass = new SomeClass();
    someClass.doSomething();
  }

  public void doSomething()
  {

    loginButton.addActionListener(new ActionListener()
    {

      @Override
      public void actionPerformed(ActionEvent e)
      {
        Scanner scanner = new Scanner(System.in);
        BufferedReader rd = null;
        String line;
        boolean gothrew = false;
        boolean ifDOES = false;
        String Username;
        String Password;
        Password = login_username.getText().trim();
        Username = login_password.getText().trim();
        try
        {
          rd = new BufferedReader(new FileReader(
              "C:\\users\\Dominik Gyarmati\\AppData\\Roaming\\KeepSafe\\users\\"
                  + login_username.getText() + ".txt"));
        }
        catch (FileNotFoundException ex)
        {
          JOptionPane.showMessageDialog(null, "Your Account doesn't exist");
        }
        try
        {
          while ((line = rd.readLine()) != null)
          {

            if (check == null)
            {
              check = line;
              check.trim();
              gothrew = true;
              System.out.println(check);
            }
            else if (gothrew == true)
            {
              check2 = line;
              check2.trim();
              System.out.println(check2);
              gothrew = false;
              ifDOES = true;
            }

            else if (check.equals(Username) && check2.equals(Password))
            {

              JOptionPane.showMessageDialog(null,
                  "You've logged into your account");
              check = null;
              check2 = null;
              ifDOES = false;
            }
            else
            {
              JOptionPane.showMessageDialog(null,
                  "Username or Password is wrong");
              check = null;
              check2 = null;
              ifDOES = false;
            }
          }
        }
        catch (IOException ioexex)
        {}
      }
    });
  }
}

EDIT: I just had to change

   else if (check.equals(Username) && check2.equals(Password))  

to

   else if (check.equals(login_username.getText().trim()) && 
  check2.equals(login_password.getText().trim())) {

Answer 1

First of all, your code smells bad:

• do not use capitalized names for variables,
• fix identation,
• use try-with-resources when read from file,
• do not use hardcoded strings,
• properly use String.trim() as strings are immutable,
• properly process exceptions and so on.

Secondly, try to use debug tools: debugging perfectly answers to your question.

And finally, check this lines:

Password = login_username.getText().trim();
Username = login_password.getText().trim();

Replace Password with Username and vice versa.