Java Graphics How to - Convert BufferedImage to Data URI for HTML image data:image/png;base64

Question

We would like to know how to convert BufferedImage to Data URI for HTML image data:image/png;base64.

Answer

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
//from   www . ja va  2s.  c o m
import javax.imageio.ImageIO;
import javax.xml.bind.DatatypeConverter;

public class Main {

    public static void main(String[] args) throws Exception {
        int size = 200;
        BufferedImage image = new BufferedImage(
                size, size, BufferedImage.TYPE_INT_ARGB);

        Graphics2D g = image.createGraphics();
        g.setRenderingHint(
                RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        g.setColor(Color.BLUE);
        for (int i = 0; i < size; i += 5) {
            g.drawOval(i, i, size - i, size - i);
        }
        g.dispose();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(image, "png", baos);

        String data = DatatypeConverter.printBase64Binary(baos.toByteArray());
        String imageString = "data:image/png;base64," + data;
        String html = "<html><body><img src='" + imageString + "'></body></html>";
        System.out.println(html);
    }
}

The code above generates the following result.