响应状态及其含义

当我们访问一个网页时，浏览器会向网页所在服务器发出请求。服务器返回给浏览器的信息中包含 HTTP 状态码的信息头，其中的状态码就是响应状态码。

HTTP 响应状态码分为五大类：

信息响应（1--）：服务器收到请求，需要请求者继续执行操作
成功响应（2--）：请求的操作被成功接收并处理
重定向（3--）：需要进一步操作以完成当前请求
客户端错误（4--）：请求包含语法错误或无法完成请求
服务端错误（5--）：服务器在处理请求的过程中发生了错误

请求详细定义看这里：RFC2616

1-- 信息响应

100 "continue"
101 "switching protocols"
102 "processing"
103 "early hints"

2-- 成功响应

200 "ok"
201 "created"
202 "accepted"
203 "non-authoritative information"
204 "no content"
205 "reset content"
206 "partial content"
207 "multi-status"
208 "already reported"
226 "im used"

3-- 重定向

300 "multiple choices"
301 "moved permanently"
302 "found"
303 "see other"
304 "not modified"
305 "use proxy"
307 "temporary redirect"
308 "permanent redirect"

4-- 客户端错误

400 "bad request"
401 "unauthorized"
402 "payment required"
403 "forbidden"
404 "not found"
405 "method not allowed"
406 "not acceptable"
407 "proxy authentication required"
408 "request timeout"
409 "conflict"
410 "gone"
411 "length required"
412 "precondition failed"
413 "payload too large"
414 "uri too long"
415 "unsupported media type"
416 "range not satisfiable"
417 "expectation failed"
418 "I'm a teapot"
421 "misdirected request"
422 "unprocessable entity"
423 "locked"
424 "failed dependency"
425 "too early"
426 "upgrade required"
428 "precondition required"
429 "too many requests"
431 "request header fields too large"
451 "unavailable for legal reasons"

5-- 服务端错误

500 "internal server error"
501 "not implemented"
502 "bad gateway"
503 "service unavailable"
504 "gateway timeout"
505 "http version not supported"
506 "variant also negotiates"
507 "insufficient storage"
508 "loop detected"
510 "not extended"
511 "network authentication required"