Need to get a JPG from stream, resize, convert again to JPG and save in DB

Question

Hi:
I have a J2EE Applicaction wich is a migration from a ASP.NET project to Java.
That web application is like a photo album service, where people can upload pictures. I take the pictures inside a bussiness object, containing two some fields, but one for the image is being uploaded and other one for the small representation of that picture, I mean a Thumbail or a resized image.
Everything works excepct one thing, I dont know how to generate the thumbail. I seen lot of information about that, included JAI, but the problem is the next... I need to resize the image, and then, to save it into my bussiness object as a JPG image. I found how to resize the image, but always explanations stop there, and I need to know if exists one esasier way to do that (JAI is simply great, but for my project should to be too much), and how to implement a solution for my problem.
In a few words:
1 I have the JPG picture (as byte[]) inside one property in one of my objects
2 I need to save in the other property a small version of the JPG picture, so I need to resize and preserve JPG format, and be able to get the byte[] of the picture.
If is posible to help my, it could help me so much!!!!
Plaase, excuse me for my horrible english, and greetings from Madrid.

Answer 1

Hi, thanks so much!... After of working on it, I got the nest code using JPEGEncode, but when trying to get image I get a expection wich says:
com.sun.image.codec.jpeg.ImageFormatException: Not a JPEG file: starts with 0x31 0xff
     sun.awt.image.codec.JPEGImageDecoderImpl.readJPEGStream(Native Method)
I'll post my code here, coz may be is something I am doing wrong, please if you could help me on it, it could be great. The code is about one servlet:
Thanks for all again!
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
boolean isMultiPart;
isMultiPart = ServletFileUpload.isMultipartContent(request);
DiskFileUpload fu = new DiskFileUpload();
fu.setSizeMax(10240*512);
fu.setSizeThreshold(40960);
fu.setRepositoryPath("/tmp");
try {
Iterator i = fu.parseRequest(request).iterator();
FileItem actual = null;
while (i.hasNext()){
actual = (FileItem)i.next();
String fname = actual.getName();
Photo oPhoto = new Photo();
oPhoto.setDesPhoto("sticked title");
oPhoto.setBytesOriginal(actual.get());
//creating the bufferedImage from a JPEG stream
InputStream in = new ByteArrayInputStream(actual.get());
JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(in);
BufferedImage image = decoder.decodeAsBufferedImage();
in.close();
//preparing thumbail numbers
int thumbWidth = 150;
int thumbHeight = 150;
double thumbRatio = (double)thumbWidth / (double)thumbHeight; //ratio for the thumbail
//obtain the picture width and height
int imageWidth = image.getWidth(null);
int imageHeight = image.getHeight(null);
//it will works if the size of image is bigger than thumbail details
if (imageWidth > 150 || imageHeight > 150) {
double imageRatio = (double)imageWidth / (double)imageHeight; //ratio in the original image
if (thumbRatio < imageRatio) {
thumbHeight = (int)(thumbWidth / imageRatio);
} else {
thumbWidth = (int)(thumbHeight * imageRatio);
// scale it to the new size on-the-fly
BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = thumbImage.createGraphics();
graphics2D.setRenderingHint(java.awt.RenderingHints.KEY_INTERPOLATION, java.awt.RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);
try {
ByteArrayOutputStream sout = new ByteArrayOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(sout);
JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);
int quality = Math.max(0, Math.min(650, 100));
param.setQuality((float)quality / 100.0f, false);
encoder.setJPEGEncodeParam(param);
encoder.encode(thumbImage, param);
oPhoto.setBytesThumb(sout.toByteArray());
sout.close();
} catch (java.io.IOException ioe) {
ioe.printStackTrace();
} // end if image width or height
oPhoto.setAlbumID(1);
if(oPhoto.getBytesOriginal().length > 1) {
oPhoto.add();
} catch (FileUploadException exception) {
out.close();
}