University Department of Management Science Sub Campus Osmanabad Seminar Topic Hypertext Transfer Protocol Guided By Mr. Varunraj Kalse Conducted By Mr. Vikrant S. Potdar M.C.A. Sem III
Introduction • Introduction to Hypertext Transfer Protocol(HTTP) • HTTP Communication • Request Headers • Request Methods • Responses • Status Codes • Error Status Codes
Introduction to Hypertext Transfer Protocol • It is a method of transferring information over world wide web. • It provides a way to publish HTML pages. • World wide web consortium and Internet Engineering Task Force(IETF) develops this protocol. • In these days we use Http1.1 version. • It is request / response protocol between clients and servers. • Web browsers are called user agents and specified servers are called as origin servers. • Http clients initiate request by establishing Transmission Control Protocol • connection to the remote host. • On receiving request servers sends a status line such as Http:/1.1 200 • to the clients.
HTTP Communication • Client sends request to server then new TCP/IP connections are open using Domain name, IP address, Port number. • If port number is not defined then it take default port number 80. • Then client places the request by issuing the word “GET”. • Then Client must wait for reply from server. Server Client
Request Headers • Request line such as GET/images/logo.gif http/1.1 which requests image from the image directory. • Headers are in the format of Accept – language : en or an empty line or an optional massage body. • The request line and headers must all end with CRLF(Carriage Return followed by Line Feed). • Some headers are optional while some required by http:/1.1 protocol.
Request Methods HEAD Useful for retrieving meta information written in response header. GET Request a representation of specified resource. POST Submit a data which is processed. PUT It is useful for uploading the resources. DELETE It is useful for deleting the resources. TRACE It is useful for getting echoes of send requests. Generally it is used in search engines.
Responses It generally contains the information about server like http:/1.1 200 ok date : (date with time) server: apache/1.3.27( Unix ) last modified: (date & time) accept range : bytes content length : size of resource connection : (State of connection open/close) content type : text/html
Status Codes The first line of http response is known as status line. Status line includes numeric status code such as 404. Status also includes textual reason phrase such as “not found”. When user agent encounters the code it uses Custom status code.
Error Status Codes If status code indicate problem then user agent shows the reason phrase and the nature of problem. The above described code is called as Error Status Code.