Java provides ImageIO class for reading and writing an image. To convert an image to a byte array –
import java.io.ByteArrayOutputStream; import java.awt.image.BufferedImage; import java.io.File; import javax.imageio.ImageIO; public class ImageToByteArray { public static void main(String args[]) throws Exception{ BufferedImage bImage = ImageIO.read(new File("sample.jpg")); ByteArrayOutputStream bos = new ByteArrayOutputStream(); ImageIO.write(bImage, "jpg", bos ); byte [] data = bos.toByteArray(); } }