Drawing a circle

Question

Hi Friends,
I have the following requirement. I am relatively new to Java
1. Draw a circle
2. Draw a rectange at the center of the circle
3. Draw lines from the top edge of the circle to various points in the circle.
4. Convert this graphic into a gif or a png image.
Can this be achieved using Java 2D. If yes, can you pls provide me some sample code if possible.
Thanks a lot for your help.

Answer 1

You can also use the TextLayout class for displaying text.
import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class GraphicsTest
    public static void main(String[] args)
        GraphicsPanel panel = new GraphicsPanel();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(panel.getUIPanel(), "North");
        f.getContentPane().add(panel);
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
class GraphicsPanel extends JPanel
    Font font;
    String text;
    public GraphicsPanel()
        font = new Font("lucida bright regular", Font.PLAIN, 22);
        text = "centered text";
        setBackground(Color.white);
    protected void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int w = getWidth();
        int h = getHeight();
        int cx = w/2;
        int cy = h/2;
        int dia = Math.min(w,h)*7/8;
        g2.setPaint(Color.blue);
        g2.draw(new Ellipse2D.Double(cx - dia/2, cy - dia/2, dia, dia));
        g2.setPaint(Color.orange);
        g2.draw(new Rectangle2D.Double(cx - dia/4, cy - dia/4, dia/2, dia/2));
        g2.setPaint(Color.blue);
        double theta = -Math.PI/2;
        double
            x1 = cx,
            y1 = cy + (dia/2) * Math.sin(theta),
            x2,
            y2 = cy + (dia/4) * Math.sin(theta);
        g2.draw(new Line2D.Double(x1, y1, x1, y2));
        theta = -Math.PI*3/4;
        x1 = cx + (dia/2) * Math.cos(theta);
        y1 = cy + (dia/2) * Math.sin(theta);
        x2 = cx + (dia/4) * Math.sqrt(2) * Math.cos(-Math.PI*5/4);
        y2 = cy + (dia/4) * Math.sqrt(2) * Math.sin(-Math.PI*5/4);
        g2.draw(new Line2D.Double(x1, y1, x2, y2));
        theta = -Math.PI/4;
        x1 = cx + (dia/2) * Math.cos(theta);
        y1 = cy + (dia/2) * Math.sin(theta);
        x2 = cx + (dia/4) * Math.sqrt(2) * Math.cos(Math.PI/4);
        y2 = cy + (dia/4) * Math.sqrt(2) * Math.sin(Math.PI/4);
        g2.draw(new Line2D.Double(x1, y1, x2, y2));
        g2.setFont(font);
        FontRenderContext frc = g2.getFontRenderContext();
        float textWidth = (float)font.getStringBounds(text, frc).getWidth();
        LineMetrics lm = font.getLineMetrics(text, frc);
        float x = (w - textWidth)/2;
        float y = (h + lm.getHeight())/2 - lm.getDescent();
        g2.drawString(text, x, y);
    public JPanel getUIPanel()
        JButton save = new JButton("save");
        save.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent e)
                saveImage();
        JPanel panel = new JPanel();
        panel.add(save);
        return panel;
    private void saveImage()
        int w = getWidth();
        int h = getHeight();
        BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = bi.createGraphics();
        paint(g2);
        g2.dispose();
        try
            ImageIO.write(bi, "png", new File("test.png"));
        catch(IOException ioe)
            System.out.println("IOE: " + ioe.getMessage());
}