Practical Examples of Java Swing GUI Examples

Introduction to Java Swing GUI Examples

Java Swing is a powerful toolkit for building graphical user interfaces (GUIs) in Java. It allows developers to create visually appealing and interactive applications. In this article, we’ll explore three diverse and practical examples of Java Swing GUI applications. These examples are suitable for beginners and demonstrate different functionalities you can implement using Swing.

Example 1: Simple Calculator

Context

This example demonstrates a basic calculator application that performs addition, subtraction, multiplication, and division. It’s a great starting point for understanding how to handle user input and display results in a Swing GUI.

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

public class SimpleCalculator {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Simple Calculator");
        frame.setSize(400, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new GridLayout(4, 2));

        JTextField num1Field = new JTextField();
        JTextField num2Field = new JTextField();
        JTextField resultField = new JTextField();
        resultField.setEditable(false);

        JButton addButton = new JButton("Add");
        JButton subButton = new JButton("Subtract");
        JButton mulButton = new JButton("Multiply");
        JButton divButton = new JButton("Divide");

        addButton.addActionListener(e -> {
            double num1 = Double.parseDouble(num1Field.getText());
            double num2 = Double.parseDouble(num2Field.getText());
            resultField.setText(String.valueOf(num1 + num2));
        });

        subButton.addActionListener(e -> {
            double num1 = Double.parseDouble(num1Field.getText());
            double num2 = Double.parseDouble(num2Field.getText());
            resultField.setText(String.valueOf(num1 - num2));
        });

        mulButton.addActionListener(e -> {
            double num1 = Double.parseDouble(num1Field.getText());
            double num2 = Double.parseDouble(num2Field.getText());
            resultField.setText(String.valueOf(num1 * num2));
        });

        divButton.addActionListener(e -> {
            double num1 = Double.parseDouble(num1Field.getText());
            double num2 = Double.parseDouble(num2Field.getText());
            if (num2 != 0) {
                resultField.setText(String.valueOf(num1 / num2));
            } else {
                resultField.setText("Cannot divide by zero");
            }
        });

        frame.add(new JLabel("Number 1:"));
        frame.add(num1Field);
        frame.add(new JLabel("Number 2:"));
        frame.add(num2Field);
        frame.add(new JLabel("Result:"));
        frame.add(resultField);
        frame.add(addButton);
        frame.add(subButton);
        frame.add(mulButton);
        frame.add(divButton);

        frame.setVisible(true);
    }
}

Notes

• You can enhance this calculator by adding more functions, such as square root or percentage calculations.
• Consider adding input validation to ensure that users enter only valid numbers.

Example 2: To-Do List Application

Context

This example features a simple to-do list application, allowing users to add and remove tasks. This application showcases how to manage a list of items dynamically in a Swing GUI.

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

public class TodoListApp {
    private static DefaultListModel<String> taskListModel;

    public static void main(String[] args) {
        JFrame frame = new JFrame("To-Do List");
        frame.setSize(300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new BorderLayout());

        taskListModel = new DefaultListModel<>();
        JList<String> taskList = new JList<>(taskListModel);
        JScrollPane scrollPane = new JScrollPane(taskList);

        JTextField taskField = new JTextField();
        JButton addButton = new JButton("Add Task");
        JButton removeButton = new JButton("Remove Task");

        addButton.addActionListener(e -> {
            String task = taskField.getText();
            if (!task.isEmpty()) {
                taskListModel.addElement(task);
                taskField.setText("");
            }
        });

        removeButton.addActionListener(e -> {
            int selectedIndex = taskList.getSelectedIndex();
            if (selectedIndex != -1) {
                taskListModel.remove(selectedIndex);
            }
        });

        JPanel inputPanel = new JPanel();
        inputPanel.setLayout(new BorderLayout());
        inputPanel.add(taskField, BorderLayout.CENTER);
        inputPanel.add(addButton, BorderLayout.EAST);

        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(inputPanel, BorderLayout.NORTH);
        frame.add(removeButton, BorderLayout.SOUTH);

        frame.setVisible(true);
    }
}

Notes

• You can extend this application by implementing features like saving the to-do list to a file or adding deadlines for tasks.
• Consider using checkboxes to mark tasks as completed.

Example 3: Simple Text Editor

Context

This example showcases a basic text editor, which allows users to type and edit text. This application highlights text input and formatting features available in Java Swing.

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

public class SimpleTextEditor {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Simple Text Editor");
        frame.setSize(600, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JTextArea textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);
        frame.add(scrollPane);

        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        JMenuItem saveItem = new JMenuItem("Save");
        JMenuItem openItem = new JMenuItem("Open");

        saveItem.addActionListener(e -> {
            // Implement save functionality
            JOptionPane.showMessageDialog(frame, "Save feature not implemented yet.");
        });

        openItem.addActionListener(e -> {
            // Implement open functionality
            JOptionPane.showMessageDialog(frame, "Open feature not implemented yet.");
        });

        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        menuBar.add(fileMenu);
        frame.setJMenuBar(menuBar);

        frame.setVisible(true);
    }
}

Notes

• This simple text editor can be expanded to include additional features like cut, copy, paste, and undo functionality.
• You could also implement file chooser dialogs for saving and opening text files.

These examples of Java Swing GUI Examples provide a solid foundation for anyone looking to get started with creating graphical applications in Java. Each project can be expanded and improved upon, allowing you to grow your skills as a programmer!