HTTP

Hyper Text Transfer Protocol

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  • Stateless : every Request is INDEPENDENT
    • regard each request as a single transaction
    • use cookie session localStorage … to enhance user experience( memorize the state from the user )

HTTPS

Hyper Text Transfer Protocol Secure

  • Data sent is encrypt
    • SSL – Secure Sockets Layer
    • TLS – Transfer Layer Security
  • install certificate on web host to use HTTPs

Message

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Headers

  • General
    • Request URL、Request Method、Status Code、Remote Address、Referrer Policy
  • Request
    • Cookies、Accept-xxx、Content-Type、Content-Length、Auhurization、User-Agent、Referrer
  • Response
    • Server、Set-Cookie、Content-Type、Content-Length、Date

Status Code

Status Code Means
1xx request received / processing
2xx Success received, understood, accepted
3xx Further action must be taken / redirect
4xx Client error
5xx Server error
  • 200 - OK
  • 201 - OK created
  • 301 - Move to new URL
  • 304 - Not Modified (Cached version)
  • 400 - Bad Request （❌ not sending correct data）
  • 401 - Unauthorized （missing token）
  • 404 - Not Found (resources do not exsist)
  • 500 - Internal Server Error

HTTP2

multiplexing

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