如何计算java BufferedImage filesize

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class BufferedImageSize {

    public static void main(String[] args) throws IOException {
        BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
        int fileSize = getBufferedImageFileSize(image, "jpg");
        System.out.println("File size: " + fileSize + " bytes");
    }

    public static int getBufferedImageFileSize(BufferedImage image, String format) throws IOException {
        ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
        javax.imageio.ImageIO.write(image, format, byteStream);
        byte[] imageData = byteStream.toByteArray();
        return imageData.length;
    }
}