HTTP EXAMPLE 1 1. User makes request 2. Browser sends HTTP request to server GET /comp1274/randyc/lab10done/enter_country.htm HTTP/1.1 Accept: */* Accept-Language: en-us,en-ca;q=0.5 Accept-Encoding: gzip, deflate User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1; .NET CLR 2.0.50727) Host: csweb2.mtroyal.ca Connection: Keep-Alive http://en.wikipedia.org/wiki/HTTP_persistent_connection Sử dụng cùng một TCP connection cho nhiều HTTP request HTTP Request Browser Web Server 3. Server receives and processes the HTTP request HTTP Request Browser Web Server Retrieve Requested file 4. Server sends HTTP response back HTTP/1.1 200 OK Server: Microsoft-IIS/5.0 Date: Thu, 30 Mar 2006 19:50:54 GMT Server Content-Type: text/html Accept-Ranges: bytes Last-Modified: Fri, 24 Mar 2006 17:50:50 GMT HTTP Response Content-Length: 209 Browser <HTML><HEAD><TITLE>Enter A Country</TITLE></HEAD> <BODY> <FORM METHOD=POST ACTION=form_filter.asp> Enter Country Search: <INPUT TYPE=TEXT NAME=Search><P> <INPUT TYPE=SUBMIT> </FORM> </BODY></HTML> 5. Browser displays response 6. User submits data 7. Browser sends HTTP request to server POST /comp1274/randyc/lab10done/form_filter.asp HTTP/1.1 Accept: */* Referer: http://csweb2.mtroyal.ca/comp1274/randyc/lab10done/enter_country.htm Accept-Language: en-us,en-ca;q=0.5 Content-Type: application/x-www-form-urlencoded Accept-Encoding: gzip, deflate User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1; .NET CLR 2.0.50727) Host: csweb2.mtroyal.ca Content-Length: 13 Connection: Keep-Alive Cache-Control: no-cache Search=Canada User entered form data goes here in the http request header as a name=value pair Digression: What if GET rather than POST? <FORM METHOD=GET ACTION=form_filter.asp> Then the user entered form data is added to the requested URL GET /comp1274/randyc/lab10done/form_filter.asp?Search=Canada HTTP/1.1 Ve