Commons-fileupload-1.2.1. 4 kB limit

Question

Hi everybody.
I am using apache commons-fileupload-1.2.1.jar to upload files (multipart data). I have copy/pasted the code from their example page:
[http://commons.apache.org/fileupload/streaming.html]
However, I have problems. When I open the inputStream to a file, and check for stream.available(), it always returns 3904 - 3916. And then I write that data down to a blob and from there save it to a file and the file is always 4 kB long.
I have checked the limits of my Apache Tomcat. It allows files up to 20 MB.
I have used this code to get the data:
            File tem = new File("/");
            FileItemFactory factory = new DiskFileItemFactory(10000000,tem);
            // Create a new file upload handler
            ServletFileUpload upload = new ServletFileUpload();
            // Parse the request
            // maximum size before a FileUploadException will be thrown
            upload.setSizeMax(10000000);
            upload.setFileSizeMax(10000000);
            upload = new ServletFileUpload(factory);
            // Parse the request
            FileItemIterator iter = upload.getItemIterator(request);
            while (iter.hasNext()) {
                FileItemStream item = iter.next();
                String name = item.getFieldName();
                InputStream stream = item.openStream();
                if (item.isFormField()) {
                     // source to do with form fields   
                } else {
                    BufferedInputStream bis = new BufferedInputStream(stream, 1000000);
                    out.println("Stream has: " + stream.available());
                    // prints out 3904 - 3916, depends on the file
                    byte[] temp = new byte[stream.available()];
                    int bytesRead = stream.read(temp );
                    out.print("Number of bytes read: " +bytesRead + "<br>");
                    // prints out 3904 - 3916, depends on the file
            Any ideas what to add or where the 4 kB limit is?

Answer 1

It's indeed a blocking/buffered stream. Commons FileUpload comes along with excellent documentation and examples of how to use it. Go read them. Especially the 'User Guide' and 'Frequently Asked Questions' sections at their homepage.
If you really want to know the content length beforehand, you need HttpServletRequest#getContentLength(). Only keep in mind that the client has full control over the request header values, so your code shouldn't rely that much on this.
That said, in the future you should be posting Servlet related questions at the Servlet forum.