1.javaee site; the servlet; JSP; EL, JSTL, dom, MVC; ajax; 2. software architecture classified c / s architecture: client / server (qq, online games), also known as fat client; advantages: to make full use resource client, the server is relatively small pressure; disadvantages: high maintenance costs; B / S architecture: browser / server; also called thin client; advantages: easy maintenance, do not need to install the client application; disadvantages: pressure server Great; 3.http protocol; HTTP protocol is a hypertext transfer protocol (hypertext transfer protocol) characteristics: it is TCP / IP as the basis of an application layer protocol; HTTP protocol is based on the treatment protocol request / response; HTTP It is a stateless protocol, a connectionless protocol; 4.http works created tcp connection transmission request returns the response closes the connection;
if HTTP1.1, connected to a plurality of requests may be concurrently transmitted; structure http; a request (request) of specification; 1. A request line, a plurality of message header, a body of the request (optional) request line: the GET URL protocol version; example: GET index.jsp HTTP / 1.1 message header: Some additional information about a client to a server provided () ; request body: data content sent by the client to the server;
PS:. 1 in the browser address bar enter or accessed through a hyperlink, then the request method is GET
2. If the request method is POST, the message header a little more item: content-length, is the length of the request body
3. POST request might be a request body, GET request does not request the body must
transfer data 4.GET method, POST method of communicating data through the request line (non-secure information) by the content body specification response (response) of 1. a status line, a plurality of message header, a content thereof; status line protocol status code status description HTTP / 1.1 200 ok message header: the body content: content server is returned to the client;
