Thread: JButton by pressing the enter key.

Hi friends.
How can I do ActionListener to a button with pressing the Enter key in keyboard?
My code is this:

import javax.swing.*;
import java.awt.*;
public class myclass{
	public static void main(String args[]){
		JFrame window = new JFrame();
		JTextField username, password;
		JLabel usernamelabel, passwordlabel, sentence;
		JButton button;
 
		window.setSize(400, 200);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		window.setBackground(Color.white);
		window.setResizable(false);
		window.setLayout(null);
		window.setTitle("Wellcome.");
 
		usernamelabel = new JLabel("Username: ");
		usernamelabel.setBounds(100, 40,  80, 30);
		window.add(usernamelabel);
 
		username = new JTextField("");
		username.setBounds(180, 40, 120, 30);
		window.add(username);
 
		passwordlabel = new JLabel("Password: ");
		passwordlabel.setBounds(100, 80, 80, 30);
		window.add(passwordlabel);
 
		password = new JTextField("");
		password.setBounds(180, 80, 120, 30);
		window.add(password);
 
		button = new JButton("  OK  ");
		button.setBounds(160, 120, 80, 30);
		window.add(button);
 
		sentence = new JLabel("Please enter your username and password");
		sentence.setBounds(65, 8, 270, 30);
		sentence.setForeground(Color.DARK_GRAY);
		window.add(sentence);
		window.setVisible(true);
 
 
	}
}

You may want to re-organize your code to set it up for creating a listener, capturing the event and registering the listener to the appropriate JComponents. There are a few ways to do this, such as inner classes. Alternatively, you can use anonymous classes or keep them in separate classes/packages.

ActionListeners are not suitable for capturing keyboard events (KeyEvents). Instead, you should use a key listener, either by the KeyListener or KeyAdapter. The main method can be in the same class or different class.

Here is a short outline of how you may want to re-arrange your code:

package com.blah.gui;
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class MyClass extend JFrame {
     // write all of the JComponents that will be used in any of your listeners (do not have duplicates in your constructor)     
 
     public class MyActionListener implements ActionListener {
        // override actionPerformed(ActionEvent event) {...}
     }
 
    public class MyKeyListener implements KeyListener {
       // override the 3 methods OR extend a KeyAdapter then override whichever methods you need
    }
 
     public MyClass() {
        // place your GUI components here and add to the JFrame
       // register the appropriate JComponents to the listener classes. 
    }
 
}

Originally Posted by SunshineInABag

You may want to re-organize your code to set it up for creating a listener, capturing the event and registering the listener to the appropriate JComponents. There are a few ways to do this, such as inner classes. Alternatively, you can use anonymous classes or keep them in separate classes/packages.

Agree.

ActionListeners are not suitable for capturing keyboard events (KeyEvents). Instead, you should use a key listener, either by the KeyListener or KeyAdapter. The main method can be in the same class or different class.

Disagree.

KeyListeners are quite low-level listeners and in general should be avoided with Swing applications (as is stated in the tutorials). Instead you could:

• Create an ActionListener and give the same listener to your JTextFields as you give your JButton. A JTextField's ActionListener will be triggered by pressing ENTER while it has focus.
• Make your JButton the default button for the JFrame's RootPane. This way if any component in the GUI has focus and doesn't swallow the ENTER key, then pressing enter will trigger your JButton to be pressed. For example:
  myFrame.getRootPane().setDefaultButton(myButton);