How to implement drawing board functionality using Java?

To create a drawing board functionality, you can use Java’s Swing library to create a simple drawing application. Here is a basic example code for implementing drawing board functionality:

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class DrawingBoard extends JFrame {

    private int startX, startY, endX, endY;
    private Color currentColor = Color.BLACK;

    public DrawingBoard() {
        setTitle("Drawing Board");
        setSize(800, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel controlPanel = new JPanel();
        JButton redButton = new JButton("Red");
        redButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                currentColor = Color.RED;
            }
        });

        JButton blackButton = new JButton("Black");
        blackButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                currentColor = Color.BLACK;
            }
        });

        controlPanel.add(redButton);
        controlPanel.add(blackButton);

        JPanel drawingPanel = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.setColor(currentColor);
                g.drawLine(startX, startY, endX, endY);
            }
        };

        drawingPanel.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                startX = e.getX();
                startY = e.getY();
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                endX = e.getX();
                endY = e.getY();
                drawingPanel.repaint();
            }
        });

        getContentPane().add(controlPanel, BorderLayout.NORTH);
        getContentPane().add(drawingPanel, BorderLayout.CENTER);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                DrawingBoard drawingBoard = new DrawingBoard();
                drawingBoard.setVisible(true);
            }
        });
    }
}

This code creates a simple drawing board application where users can draw straight lines on the canvas and choose the color of their drawings. Users can draw lines by pressing and dragging the mouse. You can extend this example code as needed to implement more complex drawing features, such as drawing different shapes, using different brush styles, and so on.