byte[] png = dstemp.getBlobAsByteArray(i, "dpmnpng"); //讀入的png圖片
InputStream input = new ByteArrayInputStream(png);
BufferedImage bufferedImage = ImageIO.read(input);
if (bufferedImage.getTransparency() == Transparency.TRANSLUCENT) {
bufferedImage = get24BitImage(bufferedImage, Color.WHITE);
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "jpg", baos);
byte[] jpg = baos.toByteArray(); //得到的jpg圖片