Question

How do you add an ActionListener to a JTextField in Java?

Answer 1

You can add an ActionListener to a JTextField in Java by calling the addActionListener() method, passing in an instance of a class that implements the ActionListener interface, like this:

textField.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("Text entered: " + textField.getText());
    }
});
 

Here is an example program that demonstrates some of these concepts:

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

public class TextFieldExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JTextField textField = new JTextField();
        textField.setPreferredSize(new Dimension(200, 20));

        textField.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("Text entered: " + textField.getText());
            }
        });

        frame.add(textField);
        frame.pack();
        frame.setVisible(true);
    }
}
 

This program creates a JFrame with a JTextField that has a preferred size of 200 pixels by 20 pixels. It also adds an ActionListener to the JTextField that prints out the text entered whenever the user presses the "Enter" key.