How to rotate an ellipse

Question

How would I change this code (shamelessly taken from one of DrLaszloJamf's posts) to rotate the ellipse around its center, I need an image with several ellipses at several different angles.
import java.awt.*;
import java.awt.image.*;
import javax.swing.*;
import java.io.*;
import javax.imageio.ImageIO;
public class BW
public static void main(String[] args) throws IOException
byte[] two = {0, (byte)0xff};
ColorModel cm = new IndexColorModel(1, 2, two, two, two);
WritableRaster raster = cm.createCompatibleWritableRaster(650, 100);
BufferedImage image = new BufferedImage(cm, raster, false, null);
Graphics2D g = image.createGraphics();
g.setColor(Color.WHITE);
g.fillArc(200, 10, 60, 30, 45, 360);
g.dispose();
ImageIO.write(image,"png",(new File("output.png")));

Answer 1

You need to use java.awt.geom.AffineTransform, either directly or through the transform that the Graphics2D
object has.
Here is a simple example that animates using rotation.
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
public class RotatingShape extends JPanel {
     private Shape shape;
     private double angle;
     private Timer timer = new Timer(500, new ActionListener(){
          public void actionPerformed(ActionEvent evt) {
               angle += Math.PI/50;
               repaint();
     //rotates shape around its origin, which is placed in center of component
     public RotatingShape(Shape shape) {
          this.shape = shape;
          timer.start();
     protected void paintComponent(Graphics g) {
          super.paintComponent(g);
          Insets insets = getInsets();
          int w = getWidth() - insets.left - insets.right;
          int h = getHeight() -insets.top  - insets.bottom;
          Graphics2D g2 = (Graphics2D) g.create(insets.left, insets.top, w, h);
          g2.setColor(getForeground());
          g2.translate(w/2.0, h/2.0);
          g2.rotate(angle);
          g2.setStroke(new BasicStroke(3));
          g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
          g2.draw(shape);
     public static void main(String[] args) {
          Shape shape = new Ellipse2D.Float(-100, -200, 200, 400);
          JComponent comp = new RotatingShape(shape);
          comp.setBackground(Color.BLACK);
          comp.setForeground(Color.GREEN);
          comp.setPreferredSize(new Dimension(450, 450));
          JFrame f = new JFrame("RotatingShape");
          f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          f.getContentPane().add(comp);
          f.pack();
          f.setLocationRelativeTo(null);
          f.setVisible(true);
}