How can I make a JMenuItem open a JTextField when I click it?

Question

I am writing code that lets the user enter, search for and remove participants. Right now I have the JFrame that has a JMenu on it with a few JMenuItems. When I ran the program and have the JMenuItems print something, it works fine. But, for example with the addItem JMenuItem, when addItem is clicked, I want it to open up a JTextField. The code I have isn't working. Can anyone explain why? Or offer a solution where when the JMenuItems are clicked JTextFields will open? Thank you.

public class MyFrame extends JFrame implements ActionListener{

JMenuBar menuBar;
JMenu fileMenu;
JMenu exitMenu;
JMenuItem addItem;
JMenuItem searchItem;
JMenuItem groupItem;
JMenuItem removeItem;
JMenuItem exitItem;

MyFrame(){
    
    this.setTitle("Swim Lessons");
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setSize(250, 250);
    //this.setSize(1436, 810);
    this.setLayout(null);
    
    menuBar = new JMenuBar();
    
    fileMenu = new JMenu("File");
    exitMenu = new JMenu("Exit");
    
    addItem = new JMenuItem("Add Child");
    searchItem = new JMenuItem("Find Child");
    groupItem = new JMenuItem("Find Group");
    removeItem = new JMenuItem("Remove Child");
    exitItem = new JMenuItem("Exit");
    
    
    addItem.addActionListener(this);
    searchItem.addActionListener(this);
    groupItem.addActionListener(this);
    removeItem.addActionListener(this);
    exitItem.addActionListener(this);
    
    fileMenu.add(addItem);
    fileMenu.add(searchItem);
    fileMenu.add(groupItem);
    fileMenu.add(removeItem);
    exitMenu.add(exitItem);
    
    menuBar.add(fileMenu);
    menuBar.add(exitMenu);
    
    this.setJMenuBar(menuBar);
    
    this.setVisible(true);
    
}

@Override
public void actionPerformed(ActionEvent e) {
    if(e.getSource() == addItem) {
        JTextField name = new JTextField();
        name.setPreferredSize(new Dimension(100,100));
        this.add(name);
        this.setVisible(true);
    }
    if(e.getSource() == searchItem) {
        System.out.print("pee ");
    }
    if(e.getSource() == groupItem) {
        System.out.print("beep ");
    }
    if(e.getSource() == removeItem) {
        System.out.print("boop ");
    }
    if(e.getSource() == exitItem) {
        System.exit(0);
    }
}
}

Side note: I do have all my imports and the class header. This site just isn't letting me add them to the code section for some reason.

Answer 1

Start by taking a look at How to Make Dialogs

if (e.getSource() == addItem) {
    String input = JOptionPane.showInputDialog(this, "Item description", "Add item", JOptionPane.PLAIN_MESSAGE);
    if (input != null) {
        System.out.println("You have entered " + input);
    }
}

Don't use null layouts, these will come back to haunt you