Is the HTTP message exchange of data between server and client
There are two types of messages:
- Request - sent by the client to a server on the triggering action
- Appropriate - response from the server
First, the configuration of the HTTP response
State 1, Line
HTTP response start line is called a status line, contains the following information:
- Protocol version, usually HTTP / 1.1
- Status code, indicating that the request is a success or failure. Common status code 202,404, or 302
- Status text. A brief, purely informational, status code via text description to help people understand the HTTP message
2、Headers
Corresponding HTTP headers and any other header follow the same structure: a case-insensitive string, followed by a code number (:) and the value of a structure depends on the type of header, the entire header (including the value) appears as a single line form
3、Body
The last part of the response is a body, not all responses have body: specific response status code (e.g., 201 or 204) is not usually the body
Second, the common status codes
1 success
- 200-ok
- 201-created
2. Redirect
- 300-Mutiple Choice
- 301-Moved Permanently
- 302-Found
3, client error
400-Bad Request
401-Unauthorized
402-Payment Required
403-Forbidden
404-Not Found
4, client error
500-Internal Server Error
501-Not Implemented
502-Bad Gateway