3xx 重定向 (Redirection)

完成请求需要进一步的动作（通常是转到另一个 URL）。301、302 是典型代表。

300Multiple ChoicesThe request has more than one possible response; the client or user should choose one.301Moved Permanently 常用The resource has permanently moved to a new URL given in the Location header.302Found 常用The resource temporarily resides at a different URL; keep using the original URL.303See OtherThe response is at another URL and should be retrieved with GET.304Not Modified 常用The cached copy is still valid, so no body is sent.305Use ProxyThe resource must be accessed through the proxy in the Location header. Deprecated.307Temporary RedirectTemporary redirect that requires the client to reuse the same HTTP method.308Permanent RedirectPermanent redirect that requires the client to reuse the same HTTP method.