Analysis of HTTP protocol data structure

One: Network protocol HHTP

Hypertext Transfer Protocol

RFC2616

II: Main structure of HTTP message

1) Request

Method (Get,post)---request method

URL-------Request Address

Header------Request Header

Body--------Request Body

2) Response

Status code-------state codes

Header--------Response Header

Body--------Response Body

Three: HTTP status code

200: Success, this success only means that the server normal processing is complete, and does not represent the correctness of the logic

301,320: Jump, generally can see in the header location, that is, jump address, the difference is a temporary jump is a fixed jump

304: Unmodified, the server discovers that the resource file identity is not changed, and notifies the client to read the local cache file.

400: Client Request Information Format problem

403: Generally prohibit access, such as files, directories, etc. exist, but do have access restrictions

404: Generally a file, directory does not exist, but can also disguise other situations as non-existent

500: The appearance of this is generally the service side of the code directly throws an exception causes

502,503,504: This is similar, in the case of network anomalies and so on can appear, there are a lot of code thrown when the error occurs

Four: HTTP general header information and function (Request)

Host: must exist, domain name specified (similar and categorized, but Port used to differentiate access to that domain name)

Accept: Represents an acceptable type of information, similar to the recommendation, has children

User-agent: Client Identity information (System version, browser, kernel, etc.)

Cookies: Special information storage locations for automatic interaction without code interference

Referer: The source, that is, the request triggered by what page or file, if it is the browser address bar carriage return does not have this value

Connection: Control length link, tell the other side the current link status (Keep-alive,close)

Range: Specifies the range of information returned (breakpoint persistence subclass use)

Content-type: Type of request body, encoding and other information

Content-length: Request Body length

If-modifiled-since: Cache-dependent, local file identification validity period

If-none-match: Cache-dependent, local file signature, corresponding to the ETag in the return message

V: HTTP General header information and function (Reaponse)

Date: Time, typically the current time of the server

Content-encoding: Returns the compression encoding type of the body

Content-length: Returns the length of the body

Content-type: Returns the type of body, encoding and other information

Cache-control: Caching mechanisms and policies, time, methods, etc.

Etag: Returns the signature of the file information

Expires: The cache of returned file information has a deadline

Set-cookie: A Cookie that requires settings, header information that can occur multiple times

Location: Auto Redirect to other new addresses, general status 301,302 appears

Connection: Control long link, tell the other side of the current link state, the default keep, when both sides are keep when the link will be in the next

Analysis of HTTP protocol data structure