HTTP is stateless, what does that mean?
The server does not know the previous HTTP request
In HTTP everything is sent and received in…
Clear text
HTTPS
HTTP over a secured TLS connection (HTTPS)
HTTP request content
HTTP Method -> GET, PUT, PATCH, POST, DELETE
Target -> URL
Protocol Version -> HTTP/1.1, HTTP/2
Headers -> meta information
Body -> data
HTTP Request Header Fields
Accept -> what kind of response resource type to accept
User-Agent -> the product sending the request
Cookie -> Sends a cookie to the server
Authorization -> Authorization method and credentials…
HTTP Response content
Protocol Version -> HTTP/1.1, HTTP/2
Status Code -> e.g., 200, 404
Status Text -> e.g., OK, Not Found
Headers -> meta information
Body -> e.g., the requested resource or an error page
HTTP Response Header Fields
Age: estimate of seconds since the response was generated
Expires: at what date/time is the response considered “stale” (=outdated)
Allow: list of http methods allowed for this resource
Content-Type: media type of the resource
Set-Cookie: saves a cookie on client side
What does URL stand for?
Uniform Resource Locator
HTTP Methods (Verbs)
9 different kinds of requests
Common:
GET -> request a representation of the specified resource
POST-> submit an entity to the specified resource
PUT-> replaces the target resource with the request payload
PATCH-> apply partial modifications to a resource
DELETE-> Delete the specified resource
HTTP Method Properties
Safe -> Does not cause any side effect on the server(GET)
Idempotent-> the effect on the server is the same, no matter how many times it is executed (DELETE, PUT)
Cacheable-> the response to the request can be stored for future re-use (GET, POST)
HTTP response codes
1xx -> Informational 2xx -> Success 3xx -> Redirection 4xx -> Client error 5xx -> Server error
Cookies
NOT EVIL >:)
Text saved on the client side (in browser)
The server sets the cookie, the client returns it
Can be modified
Can be deleted
