remove "content-length" item from the http header of HttpServletResponse

[Hanks Wang (hanwan)]

Hi all,
 
All http response generated by tomcat owns a http header item
"content-length".
 
How can I remove the item from the header of httpServletResponse? 
 
The reason is generate chunked http response, according the RFC, there
should be no content-length item in http header when response is
chunked-encoding.
 
Thanks a lot!
Han