HTTP

HTTPS

Support client, server mode: request-response model
Simple and fast: When requesting a service, only the request method and path need to be passed
Flexible: Allows transfer of data objects of any type
None connection: Only one request can be processed at a time. The server disconnects after the request is processed, saving resources
Stateless: Does not retain information about all previous request or response packets and has no memory for transaction processing

Example:

General head domain	describe
Connection	The type of connection that the browser wants to use preferentially for HTTP communication: keep-alive close (open and close persistent connections)
Cache-Control	Control the cache behavior: no-cache (forcing the server to verify again), no-store (not doing any caching), max-age=111111 (maximum time for caching resources in seconds), public (both client and proxy servers can use caching), private (proxy servers can not use caching)
Date	Time of packet Creation
Pragma	It is only used for request messages. The client requests that the intermediate server not return cached resources
Via	Information about the proxy server is added to each proxy server and is separated by commas
Transfer-Encoding	Transmission encoding: chunked block transmission
Upgrade	The Upgrade protocol used by the client must be websocket together with Connection: Upgrade
Warning	Warnings about cache-related issues

Request header field	describe
Accept	Media types that the client can receive correctly: Application/JSON text/plain
Accept-Charset	Acceptable character set: Unicode-1-1
Accept-Encoding	List of acceptable encoding formats: gzip Deflate
Accept-Language	List of languages that can be correctly received: zh-cn,zh; 1 = 0.9, en, 1 = 0.8
Authorization	Client authentication information: Bearer dSdSdFFlsfdjasd123, generally used for token storage
If-Match	If-mach: “123456, compared with the server file flag
If-Modified-Since	Local resource unmodified returns 304 (comparison time)
If-None-Match	Local resource unmodified returns 304 (comparison mark)
User-Agent	Client information, often used to identify the browser used by the client
Max-Forwards	Limit the number of times that can be forwarded by proxy and gateway
Proxy-Authorization	Sends authentication information to the proxy server
Range	Request a portion of something, used with if-range
Referer	The original URITE transport encoding of the request originating page, often used to prevent leasings and malicious requests

Response headers	describe
Accept-Ranges	Tells the client whether the server can accept range requests, bytes or None
Age	The amount of time a resource exists in the proxy cache
ETag	Resource identification, which changes when the resource changes
Location	The client redirects to a URL
Proxy-Authenticate	Sends authentication information to the proxy server
Server	Server name: Apache Nginx
WWW-Authenticate	Obtain the authentication scheme required by resources
Set-Cookie	The client information is used to identify users

Entity header fields	describe
Allow	The correct way to request resources is GET HEAD POST
Content-Encoding	Content encoding format: gzip Deflate
Content-Language	Content In the language: zh-CN
Content-Length	Request Body length (i.e. size of entity body) :
Content-Location	Alternate address to return data
Content-MD5	MD5 check value of content in Base64 encryption format
Content-Range	The content scope of the response body
Content-Type	The media type of the content (e.g. ‘application/json; Charset = utF-8 ‘;
Expires	The expiration time of the content
Last_modified	When the content was last modified

Extension header fields	describe
Cookie	Sends the value of the Cookie to the server
Set-Cookie	Sets the Cookie associated with the page
Refresh	The browser refreshes the document after a specified period of time or jumps to a specified location
Content-Disposition	Description of a downloadable resource by the server
# HTTP status code