ByteArrayOutputStream.size() to small?

[Ido M. Tamir]

Hi,

I am writing a ByteArrayOutputStream to a ServletOutputStream.
But my webserver tells me that i have specified an invalid length
as my contentLength.
It should be 2x + ~11 bytes longer. How could I get the correct size?


HttpServletResponse response = getResponse();
ByteArrayOutputStream bout = createStream();
response.setHeader("Content-disposition", "attachment; filename="
+ "myfile.ps");
response.setContentType("application/postscript");
response.setContentLength(bout.size() );
ServletOutputStream sout = response.getOutputStream();
bout.writeTo(sout);
bout.close();
response.flushBuffer();

 

[John C. Bollinger]

Hi,

I am writing a ByteArrayOutputStream to a ServletOutputStream.
But my webserver tells me that i have specified an invalid length
as my contentLength.
It should be 2x + ~11 bytes longer. How could I get the correct size?


HttpServletResponse response = getResponse();
ByteArrayOutputStream bout = createStream();
response.setHeader("Content-disposition", "attachment; filename="
+ "myfile.ps");
response.setContentType("application/postscript");
response.setContentLength(bout.size() );
ServletOutputStream sout = response.getOutputStream();
bout.writeTo(sout);
bout.close();
response.flushBuffer();

The code you show should get the correct size, as of the time at which
bout.size() is invoked. If, however, there is any chance that some
other thread is writing to the stream, then by the time you attempt to
dump it to the servlet's output stream it may be longer than it was when
you set the size on the response. If that doesn't explain it then I
would need to see a working example, as minimal as possible, that
exhibits the problem. Chances are that the bug is not in the part of
the code you showed.


John Bollinger
(e-mail address removed)