Question

I am uploading some image files using servelt. I want to resize the images. I converts the source to BufferedImage using below lines.

InputStream imageStream = item.getInputStream();

BufferedImage imageBuffer = ImageIO.read(imageStream);

Then i resize the image and write in a location. But, all of the output files size is 0.

I am using the following code to resize the image.

AffineTransform at = new AffineTransform();
if(sx != 0)
    at.scale( sx , sx );
AffineTransformOp ato = new AffineTransformOp(at, AffineTransformOp.TYPE_BILINEAR);
uploadImage = ato.filter(uploadImage, null); //uploadImage == BufferedImage

Is there any good way to convert inputstream to bufferedImage without damaging the image?
I am sure that the image is getting uploaded. But, after the conversion to BufferedImage, the file damaged.

I am uploading by submitting a form to doPost() method. The below line gives me the InputStream from a list item.

InputStream imageStream = item.getInputStream();

And, i am writing it by

ImageIO.write(image, "jpg", new File(path + ".jpg"));

Update

java.awt.image.ImagingOpException: Unable to transform src image
at java.awt.image.AffineTransformOp.filter(Unknown Source)
at com.pricar.servlet.imageupload.ImageUploadServlet.reSize(ImageUploadServlet.java:100)
at com.pricar.servlet.imageupload.ImageUploadServlet.doPost(ImageUploadServlet.java:74)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:943)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

Any suggesstions or link woulb be appreciative!!!

Thanks!

Answer 1

The reason your code isn’t working is in

uploadImage = ato.filter(uploadImage, null); //uploadImage == BufferedImage

Your destination image is null.

You have to create a new BufferedImage to put the scaled version into, like this:

BufferedImage dstImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
ato.filter(uploadImage, dstImage);

Then, save the dstImage (using ImageIO.write).

Edit:

An easier way to scale down the image would be to just draw it into the dstImage at the right size:

int dstWidth = 100;
int dstHeight = 100;
InputStream imageStream = item.getInputStream();
BufferedImage srcImage = ImageIO.read(imageStream);
if (srcImage == null) { System.err.println("NO SOURCE IMAGE!"); }
BufferedImage dstImage = new BufferedImage(dstWidth, dstHeight,
    BufferedImage.TYPE_INT_RGB);
dstImage.getGraphics().drawImage(
    srcImage, 0, 0, dstWidth, dstHeight, null);
ImageIO.write(dstImage, "jpg", new File(path + ".jpg"));