This article is enough for HTTP protocol

HTTP protocol details

HyperText Transfer Protocol (HTTP) HyperText Transfer Protocol. It was originally designed to provide a way to publish and receive HTML pages. HTTP is a standard for requests and responses between clients (users) and servers.

• By the userThe Web browserorOther Software ToolstoSpecify the specified port of the server (default port 80)Make an HTTP request. Request to obtain some resources stored on the server, such as: HTML files, images, documents, etc.
• The HTTP serverIn theSpecify port (default port 80)Listen for client requests. Once a client request is received, the server returns a status to the client, such asHTTP / 1.1 200 OK; And return the requested content, such as files, pictures, etc. Or an error message corresponding to the request.

HTTP request

An HTTP request consists of three parts: the request line, request-header, and request-body

1.1. Request Line

Request line format: Method request-uri HTTP-version CRLF Request line example: GET /form. HTML HTTP/1.1 /r/ N

Methods The HTTP/1.1 protocol defines eight methods to manipulate a given resource in different ways:

Request-uri Specifies the unified resource ID. For example, www.baidu.com/ http-version Indicates the HTTP Version. Example: HTTP/1.1 CRLF carriage return line feed. Example: a/r/n

1.2, the request header

Request – the header, for example:

mob-token: iammobtokeniammobtokeniammobtoken User-Agent: Demo_Android Cookie: Client_i = android# v1.0.0 # deviceid# android6.0.1; [email protected]; client_urstoken=iamtokeniamtokeniamtoken Connection: Keep-Alive Host: demo.comCopy the code

Request-header Keywords are described in the following table:

HTTP response

After the server processes the client request, it returns an HTTP response message. Similar to the HTTP request, the HTTP response is composed of three parts, namely, the status line, response-header, and Response-body.

2.1. Status lines

Status line format: http-version status-code reason-phrase CRLF Status line example: HTTP/1.1 200 OK /r/n

Status-code Status Code: the Status Code consists of three digits, indicating whether the request is understood or fulfilled. The first number of the status code defines the category of the response; the next two numbers have no specific classification.

There are five possible values for the first number:

Examples of status codes:

2.2, the response headers

The response – the header, for example:

Server: xiaxl
Date: Thu, 29 Aug 2019 06:10:55 GMT
Content-Type: application/json; charset=UTF-8Transfer-Encoding: chunked
Connection: keep-alive
vary: Accept-Encoding
Set-Cookie: XIAXL=xiaxl; Domain=demo.com; Path=/
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Response-header keywords are described in the following table:

Examples of HTTP

Here are two examples:

• An Http GET request and response;
• An Http POST request and response;

3.1 examples of Http GET

HTTP GET packet capture data is as follows:

GET /demo/getData.do? DeviceId = 123 & userId = xiaxl HTTP / 1.1 / line/request mob - token: iammobtokeniammobtokeniammobtoken / / request - the header the user-agent: Demo_Android cookies: client_i = android# v1.0.0 # deviceid# android6.0.1; [email protected]; client_urstoken=iamtokeniamtokeniamtoken Connection: Keep-Alive Host: demo.comCopy the code

HTTP GET packet capture data is as follows:

HTTP / 1.1200OK // Response status lineServer: xiaxl											// response-header
Date: Thu, 29 Aug 2019 06:10:55 GMT
Content-Type:application/json; charset=UTF- 8 -
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Set-Cookie: XIAXL=xiaxl; Domain=demo.com; Path=/

{"code":200}											// response-body
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3.2. Example of Http POST

The packet capture data in the Http POST request is as follows:

POST /demo/postData.do? Sign = HTTP / 1.1 / ABC/request line mob - token: iammobtokeniammobtokeniammobtoken / / request - the header the user-agent: Demo_Android cookies: client_i = android# v1.0.0 # deviceid# android6.0.1; [email protected]; client_urstoken=iamtokeniamtokeniamtoken Content-Length: 371 Content-Type: application/x-www-form-urlencoded; charset=utf-8 Connection: Keep-Alive Host: demo.com [{"deviceId":"123","userId":"xiaxl"}] // request-bodyCopy the code

HTTP POST packet capture data is as follows:

HTTP / 1.1200OK // Response status lineServer: xiaxueliang										// response-header
Date: Thu, 29 Aug 2019 06:09:41 GMT
Content-Type:application/json; charset=UTF- 8 -
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Set-Cookie: XIAXL=xiaxl; Domain=demo.com; Path=/

{"code":200}											// response-body
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3.3. Upload Http Post files

Http POST file upload request. Packet capture data is as follows:

POST/demo/photoUpload. Do HTTP / 1.1 / line/request mob - token: iammobtokeniammobtokeniammobtoken / / request - the header the user-agent: Demo_Android cookies: client_i = android# v1.0.0 # deviceid# android6.0.1; [email protected]; client_urstoken=iamtokeniamtokeniamtoken Content-Length: 12345 Content-Type: multipart/form-data; Boundary = F9817FCB-6AD7-4445-9F7B-2AB30578C4AC Connection: keep-alive Host: demo.com // body File data omitted... // request-bodyCopy the code

The Http POST file is uploaded, and the packet capture data is as follows:

HTTP / 1.1200OK // Response status lineServer: xiaxl											// response-header
Date: Thu, 29 Aug 2019 06:10:55 GMT
Content-Type:application/json; charset=UTF- 8 -
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Set-Cookie: XIAXL=xiaxl; Domain=demo.com; Path=/

{"code":200}											// response-body
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4. The Reponse Header of some well-known websites contains the client IP address

The Reponse headers of some well-known websites contain client IP addresses

Look at its Response Header data

Five, reference:

Wikipedia: Hypertext Transfer Protocol zh.wikipedia.org/wiki/ Hypertext Transfer Protocol…

HTTP requests and MIME introduce www.cnblogs.com/Dev0ps/p/80…

The HTTP headers, rounding kb.cnblogs.com/page/92320/

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