Clarifying areas that Craig doesn't know. See intermixed. "Craig R. McClanahan" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > On Thu, 9 Jan 2003, Justin Ruthenbeck wrote: > > > Date: Thu, 09 Jan 2003 15:09:44 -0800 > > From: Justin Ruthenbeck <[EMAIL PROTECTED]> > > Reply-To: Tomcat Users List <[EMAIL PROTECTED]> > > To: Tomcat Users List <[EMAIL PROTECTED]> > > Subject: Content-Length header set automatically? > > > > > > All appservers I've worked with have included the Content-Length header in > > all HTTP responses without any specific setting by a developer. So far as > > I know, this is not a spec requirement, though it seems to be common > > practice. Anyone out there know Tomcat's specific behavior on this? Is > > the Content-Length header set on all requests by default? Is it set only > > on certain requests? > > > > In general, container setting of the content length is not required > because the length cannot always be known in advance. HTTP headers are > sent before the response body, so if your response is longer than the > amount that is being buffered, there's no way for Tomcat to predict what > it will be. > > > I ask because we're using persistent connections with HTTP 1.1 but have a > > custom client (non-browser) who requires and accurate Content-Length > > header. My preference would be to have Tomcat handle the setting of the > > header, but I'm seeing XML HTTP responses without the header set. > > > > Any thoughts on the topic would be greatly appreciated... > > [The following describes my understanding of how Coyote works for Tomcat > 4.x and 5.x -- don't know about 3.3 or responding through a webserver > connector.] > > Tomcat sets the content length automatically in two circumstances: > > * Static files delivered by the default file-serving servlet > (because the length is known ahead of time from the directory > entry for that file)
Same for Tomcat 3.3.x > > * When the response data is small enough to fit into the > response buffer, and has not been flushed yet, and no > content length header was set by the application. > > You can tweak the response buffer size (response.setBufferSize()) if you > want to increase the number of responses that fall into the second > category, but for anything longer than the response buffer size, it is > your responsibility to buffer the data you're generating so that you can > calculate and set the content length -- *before* writing any data to the > response. This also works with 3.3.x with the CoyoteConnector (which will first ship in release for 3.3.2, but is available now in the nightly, or by installing the Coyote jars in 3.3.1). With the Http10Connector, you don't want to know ;-). With mod_jk(2) this is not (currently) true. If the servlet doesn't specify content-length, then the response will be sent as chunked. In future versions, it is likely to change to conform with the above. I don't know mod_webapp well enough to comment. > > > > > Thanks, > > justin > > Craig -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
