image dimensions

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Posts: 237

posted 18 years ago

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Hi there,

I have a servlet that permits the upload of image files (gif, jpg). The code I have can restrict the size of the file being uploaded, but I don't know of a way to test the actual dimensions of the file (width and height). I would like to have that capability. Does anyone know how to measure the dimensions of an image programmatically once you have the image file?

Thanks, Alan

Here are snippets of my existing code:

ArrayList<Integer> byteArray = new ArrayList<Integer>();
byte[] byteData = null;
 
        
try
{
  //We'll allow a maximum of 60KBytes per file
  mp = new MultipartParser(request,60000);
}
catch(IOException ioe)
{
  //ioe.printStackTrace();
  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  out.println(ServletUtilities.headWithTitle("Content Length Exceeded") + 
    "<body><h1>Content Length Exceeded</h1><p>Posted content length exceeds limit of 60KBytes. You will need to reduce the size of your image file.</p><a href=\"/scholastic/admin/ChangeCompanyLogo.jsp\">Return to Previous Page</a></body></html>");
 
   return;
}
 
InputStream is = null;
BufferedInputStream in = null;
String name = "";
FilePart fp = null;
ParamPart pp = null;
Part part = null;
 
if(part.isFile())
{
  //System.out.println("Got the file...");
  fp = (FilePart)part;
  filename = fp.getFileName();
  if(filename.endsWith(".gif"))
     filetype = "gif";
  else if(filename.endsWith(".jpg"))
     filetype = "jpg";
  is = fp.getInputStream();
  in = new BufferedInputStream(is);
 
  int data;
  while((data = in.read()) != -1)
  {
     byteArray.add(new Integer(data));
  }
  //System.out.println("Finished reading in bytes");
  byteData = new byte[byteArray.size()];
 
  for(int i = 0; i < byteArray.size(); i++)
  {
     byteData[i] = byteArray.get(i).byteValue();
  }
  //System.out.println("Finished converting ints to bytes");                       
}

William Brogden

Author and all-around good cowpoke

Posts: 13078

posted 18 years ago

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It looks to me like the javax.imageio and related packages have the classes and methods you need.
Bill

Ulf Dittmer

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Posts: 43081

posted 18 years ago

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A quick and easy way to get the dimensions is to use the ImageInfo class.

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