I am trying to resize an image from by db. Below is the webservlet where I get the blob from my database and try to resize it using UtilImage.
Problem: The image i tried to resize isn't shown in my browser and my console hasn't listed any stacktraces. After the UtilImage.resize()
call, which returns a new BufferedImage, the imageType has changed from 5 to 1.
@WebServlet("/images")
public class BildService extends HttpServlet {
private static final long serialVersionUID = 1L;
@EJB
private LesenService lesenService;
private Veranstaltung veranstaltung;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Integer veranstaltungId = Integer.parseInt(request.getParameter("id"));
veranstaltung = lesenService.getVeranstaltungByVeranstaltungId(veranstaltungId);
if (veranstaltung == null) {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
response.setContentType(veranstaltung.getFormat());
OutputStream os = response.getOutputStream();
byte[] img = UtilImage.resizeScalr(veranstaltung.getBild(), veranstaltung.getFormat());
os.write(img);
}
}
This is my UtilImage class:
public class UtilImage {
public static final byte[] resizeScalr(byte[] img, String type) {
if (img != null) {
BufferedImage bImage = getBufferedImage(img);
double scaleFactor = getScaleFactor(bImage.getWidth(), UtilKonstanten.PICTURE_WIDTH);
int targetWidth = (int) (scaleFactor * bImage.getWidth());
int targetHeight = (int) (scaleFactor * bImage.getHeight());
// return getByteArray(Scalr.resize(bImage, targetWidth,
// targetHeight), type);
return getByteArray(Scalr.resize(bImage, Scalr.Method.BALANCED, targetWidth, targetHeight), type);
}
return null;
}
private static final double getScaleFactor(int width, int wishwidth) {
return (double) wishwidth / width;
}
private static final BufferedImage getBufferedImage(byte[] array) {
InputStream is = new ByteArrayInputStream(array);
BufferedImage img;
try {
img = ImageIO.read(is);
return img;
} catch (IOException e) {
// TODO
e.printStackTrace();
}
return null;
}
private static final byte[] getByteArray(BufferedImage img, String type) {
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(img, type, os);
byte[] byteArray = os.toByteArray();
os.close();
return byteArray;
} catch (IOException e) {
// TODO
e.printStackTrace();
}
return null;
}
}
Thanks a lot for your help!
Unfortunately I didn't post the answer to this question. As far as I know it was something with the type, that wasn't saved correctly and in cause of that the browser wasn't able to resolve the type. --> "img" instead of "application/img" or something like that.