Basics of switching between forms in Java

Question

I am sure at the end of reading answers I will feel like a complete idiot, but I need help anyways. I am trying to create my first Java app with switching between forms. I am using IntelliJ IDE and using provided form designer I created some forms. My wish is to be able to switch between forms when clicking proper buttons. I tried to find answers to my questions but my problems come from my lack of experience and some basic knowledge about how to properly implement forms. I have found this, for example:

btnLogin.addActionListener(new ActionListener() 
{
    public void actionPerformed(ActionEvent e) {
        this.setVisible(false);
        new FrmMain().setVisible(true); // Main Form to show after the Login Form..
    }
});

And I am sure using this would help me achieve what I want to achieve, BUT this is not working. Maily because I have no idea what form's class file actually should contain. While making a single-form app I don't need to extend JFrame in form class, but I suppose (?) I need to when I am trying to switch between forms with this method? I don't know what should appear in contructors, I don't know if I need main functions (don't really think so) in classes other than the starting form's class. I will paste what I have now. Feel free to educate me on what should it look like. Right now I am unable to close the menu form and while opening the other form there are no contents (buttons etc, don't know why).

First form:

package ImplementedUCs;

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class MenuForm extends JFrame
{
    private JPanel MenuPanel;
    private JButton loginButton;
    private JButton profileButton;
    private JButton conferencesButton;
    private JButton usersButton;
    private JButton settingsButton;
    private JButton exitButton;
    private JLabel titleLabel;
    private JLabel logLabel;
    private JLabel userLabel;

    public static boolean loginStatus = false;
    public static UserTypes loginType = UserTypes.NOT_LOGGED_IN;
    public static MenuForm myMenuForm;

    public MenuForm()
    {
        myMenuForm = this;

        logLabel.setText("You are currently not logged in!");
        userLabel.setText("Please log in to use this application!");

        loginButton.addActionListener(new ActionListener()
        {
            @Override
            public void actionPerformed(ActionEvent e)
            {
                // want to close/hide menu form here
                new LoggingForm().setVisible(true);
            }
        });
    }

    public static void main(String[] args)
    {
        JFrame menuFrame = new JFrame("MenuForm");
        menuFrame.setContentPane(new MenuForm().MenuPanel);
        menuFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        menuFrame.pack();
        menuFrame.setTitle("ConferenceStation v1.0");
        menuFrame.setSize(800,600);
        menuFrame.setLocationRelativeTo(null);
        menuFrame.setResizable(false);
        menuFrame.setVisible(true);
    }
}

Second form:

package ImplementedUCs;

import javax.swing.*;

public class LoggingForm extends JFrame
{
    private JPanel loggingPanel;
    private JTextField loginField;
    private JPasswordField passwordField;
    private JButton remindButton;
    private JButton noAccButton;
    private JButton loginButton;
    private JLabel titleLabel;
    private JPanel properPanel;
    private JLabel loginLabel;
    private JLabel passwordLabel;
    private JLabel noAccLabel;
    private JLabel forgotLabel;

    public LoggingForm()
    {
        this.setTitle("ConferenceStation v1.0");
        this.setSize(800,600);
        this.setLocationRelativeTo(null);
        this.setResizable(false);
        this.setVisible(true);
    }
}

I am really trying to understand how it should look like and how to make it work, please, I need help.

Answer 1

Here is an example on how to use multiple JFrames even though I don't recommend it. For future reference, I suggest you use a CardLayout

MainFrame.java

import javax.swing.*;

public class MainFrame
{
    JFrame mainFrame = new JFrame("Main Frame");

    public MainFrame()
    {
        addComponents();
    }

    public void addComponents()
    {
        mainFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        mainFrame.setLocationRelativeTo(null);
        mainFrame.setExtendedState(JFrame.MAXIMIZED_BOTH);
        mainFrame.pack();
        mainFrame.setVisible(true);
    }

    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(LoginFrame::new);
    }
}

LoginFrame.java

import javax.swing.*;
import java.awt.*;

public class LoginFrame
{
    JFrame loginFrame = new JFrame("Login Frame");

    public LoginFrame()
    {
        addComponents();
    }

    public void addComponents()
    {
        JButton loginBtn = new JButton("Login");

        loginBtn.addActionListener(e -> {
            loginFrame.dispose();
            SwingUtilities.invokeLater(MainFrame::new);
        });


        loginFrame.add(loginBtn);
        loginFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        loginFrame.setLocationRelativeTo(null);
        loginFrame.setPreferredSize(new Dimension(300, 300));
        loginFrame.pack();
        loginFrame.setVisible(true);
    }
}