Methods
HEAD /echo/head/json HTTP/1.1
GET /echo HTTP/1.1
POST /echo/post/json HTTP/1.1
PUT /new.html HTTP/1.1
OPTIONS / HTTP/1.1
PUT vs POST
它們功能差不多, 不同在於對 Request-URI 的理解
PUT 用於 update or replace an existing resource on the server,
while the POST method is used to add a resource on the server.
PUT Request Method
If the Request-URI does not point to an existing resource,
the origin server MAY add a new resource with that URI.
To partially replace an existing resource, use the PATCH request method.