Image resizing with a servlet
I'm trying to write a servlet that will take an image's location and then save 3 different sized versions of it.
I've looked at the example that Joe Bella went through on the sun developer network and i understand most of it, but i can't seem to compile it. Here's the code:
publicclass ResizeImageServletextends HttpServlet
{
private String imageDir ="";
publicfinalvoid init( ServletConfig config )throws ServletException
{
// No initialization necessary
}
publicfinalvoid doGet( HttpServletRequest req, HttpServletResponse res )
throws ServletException, IOException
{
// No difference to us if it's a get or a post.
this.doPost(req,res);
}
publicfinalvoid doPost( HttpServletRequest req, HttpServletResponse res )
throws ServletException, IOException
{
try
{
int targetWidth=0;
int targetHeight=0;
// Get a path to the image to resize.
// ImageIcon is a kluge to make sure the image is fully
// loaded before we proceed.
Image sourceImage =new ImageIcon(Toolkit.getDefaultToolkit().
getImage(req.getPathTranslated())).getImage();
// Calculate the target width and height
float scale = Float.parseFloat(req.getParameter("scale"))/100;
targetWidth = (int)(sourceImage.getWidth(null)*scale);
targetHeight = (int)(sourceImage.getHeight(null)*scale);
BufferedImage resizedImage = this.scaleImage
(sourceImage,targetWidth,targetHeight);
// Output the finished image straight to the response as a JPEG!
res.setContentType("image/jpeg");
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder
(res.getOutputStream());
encoder.encode(resizedImage);
}
catch(Exception e)
{
res.sendError(HttpServletResponse.SC_BAD_REQUEST);
}
}
private BufferedImage scaleImage(Image sourceImage,int width,int height)
{
ImageFilter filter =new ReplicateScaleFilter(width,height);
ImageProducer producer =new FilteredImageSource
(sourceImage.getSource(),filter);
Image resizedImage = Toolkit.getDefaultToolkit().createImage(producer);
return this.toBufferedImage(resizedImage);
}
private BufferedImage toBufferedImage(Image image)
{
image =new ImageIcon(image).getImage();
BufferedImage bufferedImage =new BufferedImage(image.getWidth(null)
,image.getHeight(null),BufferedImage.TYPE_INT_RGB);
Graphics g = bufferedImage.createGraphics();
g.setColor(Color.white);
g.fillRect(0,0,image.getWidth(null),image.getHeight(null));
g.drawImage(image,0,0,null);
g.dispose();
return bufferedImage;
}
}
I've tried importing java.awt.* and java.util.* but it still doesn't recognise almost all of the methods at compile.
What am i doing wrong?
Thanks in advance
[5038 byte] By [
_toma_a] at [2007-10-2 1:25:21]
the main problem i'm having is that javax.servlet and javax.servlet.http are not installed on my machine - nor can i work out how to do so now i've downloaded them. So, i've rewritten it as a bean (as it doesn't really have to be a servlet anyway).
However, here are the errors i'm still getting:
ResizeImage.java:46: cannot find symbol
symbol : class BufferedImage
location: class resizeImage.ResizeImage
private BufferedImage scaleImage(Image sourceImage, int width, int height)
^
ResizeImage.java:56: cannot find symbol
symbol : class BufferedImage
location: class resizeImage.ResizeImage
private BufferedImage toBufferedImage(Image image)
^
ResizeImage.java:23: cannot find symbol
symbol : class ImageIcon
location: class resizeImage.ResizeImage
Image sourceImage = new ImageIcon(Toolkit.getDefaultToolkit().
^
ResizeImage.java:24: cannot find symbol
symbol : variable req
location: class resizeImage.ResizeImage
getImage(req.getPathTranslated())).getImage();
^
ResizeImage.java:27: cannot find symbol
symbol : variable req
location: class resizeImage.ResizeImage
float scale = Float.parseFloat(req.getParameter("scale"))/100;
^
ResizeImage.java:31: cannot find symbol
symbol : class BufferedImage
location: class resizeImage.ResizeImage
BufferedImage resizedImage = this.scaleImage
^
ResizeImage.java:35: cannot find symbol
symbol : variable res
location: class resizeImage.ResizeImage
res.setContentType("image/jpeg");
^
ResizeImage.java:36: cannot find symbol
symbol : class JPEGImageEncoder
location: class resizeImage.ResizeImage
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder
^
ResizeImage.java:37: cannot find symbol
symbol : variable res
location: class resizeImage.ResizeImage
(res.getOutputStream());
^
ResizeImage.java:36: cannot find symbol
symbol : variable JPEGCodec
location: class resizeImage.ResizeImage
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder
^
ResizeImage.java:42: cannot find symbol
symbol : variable HttpServletResponse
location: class resizeImage.ResizeImage
res.sendError(HttpServletResponse.SC_BAD_REQUEST);
^
ResizeImage.java:42: cannot find symbol
symbol : variable res
location: class resizeImage.ResizeImage
res.sendError(HttpServletResponse.SC_BAD_REQUEST);
^
ResizeImage.java:48: cannot find symbol
symbol : class ImageFilter
location: class resizeImage.ResizeImage
ImageFilter filter = new ReplicateScaleFilter(width,height);
^
ResizeImage.java:48: cannot find symbol
symbol : class ReplicateScaleFilter
location: class resizeImage.ResizeImage
ImageFilter filter = new ReplicateScaleFilter(width,height);
^
ResizeImage.java:49: cannot find symbol
symbol : class ImageProducer
location: class resizeImage.ResizeImage
ImageProducer producer = new FilteredImageSource
^
ResizeImage.java:49: cannot find symbol
symbol : class FilteredImageSource
location: class resizeImage.ResizeImage
ImageProducer producer = new FilteredImageSource
^
ResizeImage.java:58: cannot find symbol
symbol : class ImageIcon
location: class resizeImage.ResizeImage
image = new ImageIcon(image).getImage();
^
ResizeImage.java:59: cannot find symbol
symbol : class BufferedImage
location: class resizeImage.ResizeImage
BufferedImage bufferedImage = new BufferedImage(image.getWidth(null)
^
ResizeImage.java:59: cannot find symbol
symbol : class BufferedImage
location: class resizeImage.ResizeImage
BufferedImage bufferedImage = new BufferedImage(image.getWidth(null)
^
ResizeImage.java:60: cannot find symbol
symbol : variable BufferedImage
location: class resizeImage.ResizeImage
,image.getHeight(null),BufferedImage.TYPE_INT_RGB);
^
I know its an import error, i'm just not sure what i need to import
