> -----Original Message----- > From: Sebastiaan van Erk [mailto:[EMAIL PROTECTED] > Sent: Friday, April 27, 2007 7:24 PM > To: Tomcat Users List > Subject: Re: Comet: problem with request.getParameter() in > Comet POST requests > > > > GET parameters, ie parameters in the URL will work. > > However, using Comet you shouldn't rely on parameters in > the body, the > > body if for you usage, and your usage alone. > Seems to me that this is a pretty common use case though with AJAX > server side push: request, wait, response. > Comet is used to free the http thread while waiting, otherwise the > server would be out of http threads in no time. > The data posted is often in POST form (a scripted form post). > > You can still invoke getReader or getInputStream without actually > > reading from it, if that causes the parse to happen. > Yes, that is my current workaround, I use READ events and the > Content-Length header to parse the parameters myself.
Wouldn't every application which isn't as dumb as the chat example (which does not care about the content it reads but simply passes it back to it's clients) need to implement it's own mechanism to check whether there is enough input available to start parsing a chunk of data? According to my current understanding of Comet a READ event will be triggered after some tcp packet was received from the client. Thus, even if a client has sent a complete chunk of data (e.g. a SOAP request), the server side cannot be sure that it is completely available for parsing when a READ event is triggered. Thus, each application must implement it's own http like protocol to wrap each chunk of data transferred to the server: - The client must send the number of bytes of the following chunk before the actual chunk is sent. To be able to do this, it must care about content encoding (e.g. write character based data to a ByteArrayOutputStream first, determine it's length, send the number of bytes, and then the content of the byte array) - The servlet must read the length, allocate a byte buffer and start reading into the buffer. - Only if it has received a READ event that delivers the last expected byte of the chunk, the content of the byte buffer can be converted into a String (or another character based sequence) according to the character encoding specified by the client, and finally parsed. Is it really the intention of Comet that each application must care about these things? Is there no way to enable a Servlet to do a blocking read if it recognizes that a client has sent a chunk of data? It would not block for a long time in that situation (only until the missing tcp packets of the actual chunk have arrived). This would allow a much more convenient handling of input for most applications. Matthias --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
