Basic concepts of 1,HTTP requests
tcp/upd/http *2,http Meaning of the request header and Response header Request header: accept:text/html,image/* (type that the browser can receive) accept-charset:iso-8859-1 (the type of encoding the browser can receive) accept-encoding:gzip,compress (the browser can receive the compression encoding type) ACCEPT-LANGUAGE:EN-US,ZH-CN (language and country type that the browser can receive) host:www.it315.org:80 (browser-requested host and port) if-modified-since: Tue, 18:23:51 GMT (a page cache time) referer:http://www.it315.org/index.jsp (which page the request came from) user-agent: mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) (browser-related information) cookie: (Information sent by the browser staging server) connection:close (1.0)/keep-alive (1.1) (features of the HTTP request version) date:tue, 18:23:51 GMT (time to request the website) response header: location:http://www.it315.org/index.jsp ( Control which page the browser displays) server:apache tomcat (type of server) content-encoding:gzip (compression encoding sent by the server) content-length:80 ( The server sends the displayed bytecode length)  CONTENT-LANGUAGE:ZH-CN (the language and country name of the server sending the content) Content-Type:image/jpeg; Charset=utf-8 (Type and encoding type of content sent by the server) last-modified:tue, 18:23:51 GMT (the last time the server was modified)  REFResh:1;url=http://www.it315.org (Control browser 1 seconds after the forwarding URL points to the page) Content-Disposition:attachment; Filename=aaa.jpg (server control browser to download open file) transfer-encoding:chunked (server chunked pass data to client)  SET-COOKIE:SS=Q0=5LB_NQ ; Path=/search (server sends cookie-related information) expires:-1 (server control browser do not cache Web pages, default is cache) cache-control:no-cache ( server control browser do not cache Web pages) pragma:no-cache (server control browser do not cache Web pages) connection:close/keep-alive (features of HTTP request version) date:tue, 18:23:51 GMT (response to site time) *3,http Application scenario Refresh of request header and response header, regardless of cache, Fetch data from the server
Basic concepts of HTTP requests the meaning of HTTP request headers and Response headers