Errors with Blob

Question

Hi,
I'm working with servlets and jsp's but my error occurs at the Blob object level. In my jsp I have an <img> tag and the src="" of that image(which will be binary data) will be retrieved from a servlet that recieves a Blob(the image) from the session and writes it to the jsp. The error is a null pointer exception at the line where I try and get the binary stream from the Blob b, but after debugging I realize that the blob is not null. I'm not sure if the problem lies in the differences between the standard java Blob or Oracle's BLOB. I use java's but somehow, somewhere, I think it gets cast(implicity) to a BLOB. Anyone have an idea of why I get a null pointer exception and why I can't write it to the standard out
Here is some of my code:
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
resp.setContentType("image/jpeg");
HttpSession session = req.getSession(false);
Blob b = (Blob)session.getAttribute("image");
try
long length = 0L;
DataOutputStream dot = new DataOutputStream(resp.getOutputStream());
length = b.length();
InputStream blobStream = b.getBinaryStream(); ****EXCEPTION****
length = b.length();
byte x[] = new byte[10240];
for(int i = 0; (i = blobStream.read(x)) != -1;)
dot.write(x, 0, i);
blobStream.close();
Thanks

Answer 1

Sorry, small correction in the code.
the first appearence of: length = b.length();
shouldn't be there