Java Swing Tutorial

📌 Introduction to Java Swing

Java Swing is a powerful GUI (Graphical User Interface) toolkit that is part of Java’s standard library. It allows developers to build rich desktop applications with various interactive components like buttons, text fields, labels, and more.

Built on top of AWT (Abstract Window Toolkit), Swing offers more flexible and customizable components, making it a go-to choice for many developers.

🧱 Getting Started with Swing

To begin working with Swing, you don’t need to install anything extra if you're using an IDE like IntelliJ IDEA, Eclipse, or NetBeans.

Swing is part of the javax.swing package, which comes bundled with Java SE.

Basic Structure of a Swing Application:

import javax.swing.*;

public class MyFirstSwingApp {
    public static void main(String[] args) {
        JFrame frame = new JFrame("My Swing Window");
        frame.setSize(400, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

🖼️ Understanding JFrame and Basic Components

JFrame acts as the main window in any Swing application. Within this frame, you can add other components like:

• JButton - A clickable button
• JLabel - A text display element
• JTextField - A single-line text input field

Example: Adding a Button

JButton button = new JButton("Click Me");
frame.add(button);

📐 Working with Layout Managers

Layout managers control how components are arranged within containers. Java Swing provides several layout managers, such as:

• FlowLayout – Arranges components in a row, wrapping to the next line.
• BorderLayout – Divides the container into five regions: North, South, East, West, and Center.
• GridLayout – Places components in a grid of rows and columns.

Example: Using FlowLayout

frame.setLayout(new FlowLayout());
frame.add(new JButton("One"));
frame.add(new JButton("Two"));
frame.add(new JButton("Three"));

🧠 Handling Events in Swing

Event handling allows your application to respond to user actions like button clicks or key presses.

The most common way to handle events is by using ActionListener.

Example: Button Click Event

button.addActionListener(e -> {
    System.out.println("Button clicked!");
});

🛠️ Creating a Simple Login Form

Let’s create a basic login form with labels, text fields, and a button. This will help you understand how to organize components within a window.

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

public class LoginForm {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Login");
        frame.setSize(300, 150);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new GridLayout(3, 2));

        JLabel userLabel = new JLabel("Username:");
        JTextField userField = new JTextField();
        JLabel passLabel = new JLabel("Password:");
        JPasswordField passField = new JPasswordField();
        JButton loginButton = new JButton("Login");

        frame.add(userLabel);
        frame.add(userField);
        frame.add(passLabel);
        frame.add(passField);
        frame.add(new JLabel());
        frame.add(loginButton);

        frame.setVisible(true);
    }
}

🎨 Customizing the Look and Feel

Swing provides options to change the look and feel of the UI using the UIManager.

This allows your application to adapt to system styles or even third-party themes.

try {
    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
    e.printStackTrace();
}

🚀 Best Practices in Swing Development

• Always run Swing components on the Event Dispatch Thread (EDT) using SwingUtilities.invokeLater().
• Separate UI logic from business logic for better maintainability.
• Use layout managers instead of absolute positioning.

📌 Final Thoughts

Java Swing remains a solid option for creating desktop applications with Java. Although JavaFX offers a more modern approach, Swing is still widely used in many enterprise applications.

With its simplicity, flexibility, and wide range of components, Swing is a great toolkit for Java developers looking to build user-friendly interfaces.

In the next blog, we'll dive into JavaFX – the modern GUI toolkit for building responsive and stylish Java applications.