Java Swing GUI Example Program

This Java source code is an example of a Graphical User Interface (GUI) with different Java Swing GUI elements such as TextBox, Buttons, TextArea, Text Area and Labels. It is implemented using Java Swing API which provides a set of “lightweight” (all-Java language) components. This code example extends the functionality of JFrame class to show a JFrame window and Implements ActionListener on buttons to catch the click event on those buttons.

This Java Swing example uses several Swing components to create a graphical user interface (GUI). Here are the main components used in the code:

1. JFrame: The main window or frame of the GUI.
2. JComboBox: A dropdown list or combo box for selecting options.
3. JLabel: A non-editable text component used to display information or instructions.
4. JButton: A button component that triggers actions when clicked.
5. JTextArea: A multi-line text area where you can display or input text.
6. JScrollPane: A scrollable container that wraps around another component (in this case, the JTextArea) to provide scrolling functionality.
7. Container: A generic component that can hold and organize other components.
8. JCheckBox: A checkbox that allows the user to toggle a binary choice, such as enabling or disabling a feature. In this example, it’s labeled “Enable Feature.”
9. JRadioButton and ButtonGroup: JRadioButton components represent radio buttons that are grouped together using a ButtonGroup. Radio buttons within the same group ensure that only one of them can be selected at a time.
10. FlowLayout: A layout manager that arranges components in a left-to-right, top-to-bottom flow.
11. JMenuBar, JMenu, and JMenuItem: JMenuBar represents the menu bar at the top of the frame. JMenu represents a dropdown menu within the menu bar, and JMenuItem represents individual items within the menu.

These components are used to create a simple interactive program with buttons, a combo box, and text areas, providing a basic understanding of building a GUI in Java.

Java Swing GUI Example Code

Here is the java example code to show Swing GUI elements.

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

class Main extends JFrame implements ActionListener
{
    JComboBox help = new JComboBox();

    JLabel txtlabel = new JLabel("Coded by saqib at mycplus.com");

    JButton button1 = new JButton("First button");
    JButton button2 = new JButton("Second button");
    JButton button3 = new JButton("Third button");
    
    JRadioButton radioBtn1 = new JRadioButton("Option 1");
    JRadioButton radioBtn2 = new JRadioButton("Option 2");    
    ButtonGroup radioGroup = new ButtonGroup();
    
    JCheckBox checkBox = new JCheckBox("Enable Feature");

    //text area
    JTextArea output =
            new JTextArea("Output will show here in this GUI box", 14, 45);
    JLabel txtlabel2 = new JLabel("admin@mycplus.com");

    public Main()
    {
        super("Java Swing GUI Example");
        //create window
        setSize(550, 500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);

        //create content container
        Container contentArea = getContentPane();
        contentArea.setBackground(Color.gray);
        //create layout manager
        FlowLayout flowManager = new FlowLayout();
        contentArea.setLayout(flowManager);
        JComboBox help = new JComboBox();
        help.setForeground(Color.black);
        help.setBackground(Color.lightGray);

        setContentPane(contentArea);

        //combo box help
        help.addItem("Help - Dropdown Menu");
        help.addItem("-----------------");
        help.addItem("1. Menu item One");
        help.addItem("2. Menu item Two");
        help.addItem("3. Menu item Three");
        help.addItem("4. Menu item Four");

        contentArea.add(help);

        //text label
        txtlabel.setBackground(Color.darkGray);
        contentArea.add(txtlabel);
        setContentPane(contentArea);

        output.setForeground(Color.green);
        output.setBackground(Color.black);
        contentArea.add(output);
        setContentPane(contentArea);

        //scroll pane
        JScrollPane scroller = new JScrollPane(output,
                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
                JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        scroller.setForeground(Color.darkGray);
        contentArea.add(scroller);
        setContentPane(contentArea);

        //buttons
        button1.addActionListener(this);
        button1.setBackground(Color.lightGray);
        button1.setForeground(Color.black);
        contentArea.add(button1);
        setContentPane(contentArea);
        button2.addActionListener(this);
        button2.setBackground(Color.lightGray);
        button2.setForeground(Color.black);
        contentArea.add(button2);
        setContentPane(contentArea);
        button3.addActionListener(this);
        button3.setBackground(Color.lightGray);
        button3.setForeground(Color.black);
        contentArea.add(button3);
        setContentPane(contentArea);

        //text label
        txtlabel2.setBackground(Color.darkGray);
        contentArea.add(txtlabel2);
        setContentPane(contentArea);
        
        
        radioGroup.add(radioBtn1);
        radioGroup.add(radioBtn2);
        contentArea.add(radioBtn1);
        setContentPane(contentArea);
        contentArea.add(radioBtn2);
        setContentPane(contentArea);
        
        contentArea.add(checkBox);
        setContentPane(contentArea);
        
        createMenuBar();
        
        
    }

    public void actionPerformed (ActionEvent event)
    {
        if(event.getSource() == button1)
            output.setText("You pressed button1");
        if(event.getSource() == button2)
            output.setText("You pressed button2");
        if(event.getSource() == button3)
            output.setText("You pressed button3");
    }
    
    private void createMenuBar() {
        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        JMenuItem exitMenuItem = new JMenuItem("Exit");

        exitMenuItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });

        fileMenu.add(exitMenuItem);
        menuBar.add(fileMenu);

        setJMenuBar(menuBar);
    }

    public static void main (String [] args)
    {
        Main eg = new Main();
    }
}

Screenshot of the Swing GUI Example

When you compiler and run the above code, you will see a similar screens of the swing gui example as below.

Java Swing GUI Example