Upload/Download speed of files using Java

Question

Hey All,
I have created a signed Java applet which, among various other things, allows uploading and downloading of files between the server and client. Both Upload and Download is handled through HTTP. For Upload I create a multi-part POST request to transfer the data to a script on the server which intercepts it. For download I craft a URL to http://myserver.com/filedirectory/file.extension. From that I form a HttpURLConnection and read from the stream to the file system of the client. This applet is only run on an internal network, which currently has 100mbit connection. However, I am noticing upload/download speeds of less than 1MB/s (I believe 100mbit = 12MB/s approx). I am currently using a buffer size of 8kb.
Can anyone think of any ways to increase download speed? Would it help to increase the buffer size, knowing we will always be on a closed network? Here Is my upload code, and my download is similar but in the opposite direction.
int bytesRead = 0;
byte b[] = new byte[BUFFER_SIZE];
BufferedInputStream bufin =  new BufferedInputStream(new FileInputStream(f));
while ((bytesRead = bufin.read(b)) != -1)  {
        * write output
     out.write(b, 0, bytesRead);
     out.flush();
out.close();
bufin.close();I have not included the rest of the code which creates the POST request because the upload is otherwise working perfectly despite the speed, and I have confined the bottleneck to this part using debug output.
Thanks much

Answer 1

Will removing the flush after every loop somehow decrease accuracy?No.
Ideally, files should be the same exact size on the server as the client after upload has finished.Deferring the flush() can't change that. It just lets you write in larger chunks, which is always good.
Which one is the socket receive buffer?The buffer whose size is set by Socket.setReceiveBufferSize().
Currently the size of BUFFER_SIZE in the example above is set to 8k.That's the application buffer. Good size.