How do I draw a rectangle in Java 2D?

The code snippet below show you how to use the Graphics2D class the draw a rectangle. You can see the snippet in the paintComponent(Graphics g) method defined in the anonymous JPanel object.

To draw a rectangle we use the Rectangle2D.Double static-inner class. The constructor of this class accept the information about the rectangle x, y coordinates and its width and height.

package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Rectangle2D;

public class DrawRectangle {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            JFrame frame = new JFrame("Draw Rectangle");
            frame.add(new JPanel() {
                protected void paintComponent(Graphics g) {
                    // Draw a rectangle using Rectangle2D class
                    Graphics2D g2 = (Graphics2D) g;

                    double x = 100;
                    double y = 100;
                    double width = x + 200;
                    double height = y + 50;

                    // Draw the red rectangle
                    g2.draw(new Rectangle2D.Double(x, y, width, height));

                    // Draw the blue rectangle
                    g2.draw(new Rectangle2D.Double(150, 50, 200, 250));
            }, BorderLayout.CENTER);

            frame.setSize(new Dimension(500, 400));

Here is the result you’ll get when you run the snippet:

Draw 2D Rectangle

Draw 2D Rectangle



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