100 Continue
The server only received part of the request, but once the server has not rejected the request, the client should continue to send the rest of the request.
101 Switching Protocols
server conversion protocol: the server will comply with the client's request to convert to another protocol.
2xx: Success
200 OK
The request is successful (followed by the response document to the GET and POST requests)
201 The Created
request is created and a new resource is created.
202 Accepted
The request for processing has been accepted, but processing was not completed.
203 Non-authoritative Information
The document has been returned normally, but some response headers may be incorrect because a copy of the document was used.
204 No Content
There are no new documents. The browser should continue to display the original document. This status code is useful if the user periodically refreshes the page and the servlet can determine that the user's document is sufficiently up-to-date.
205 Reset Content
No new documents. But the browser should reset what it shows. Used to force the browser to clear form inputs.
206 Partial Content
The client sent a GET request with a Range header and the server completed it.
3xx: Redirect
300 Multiple Choices
. list of links. The user can select a link to reach the destination. Up to five addresses are allowed.
301 Moved Permanently
The requested page has been moved to the new url.
302 Moved Temporarily
The requested page has been temporarily moved to a new url.
303 See Other
The requested page can be found under another url.
304 Not Modified
The document was not modified as expected. The client has buffered documents and makes a conditional request (usually providing an If-Modified-Since header indicating that the client only wants documents newer than the specified date). The server tells the client that the original buffered document can still be used.
305 Use Proxy
The document requested by the client SHOULD be fetched through the proxy server indicated by the Location header.
306 Unused
This code was used in the previous version. It is no longer used, but the code is still preserved.
307 Temporary Redirect
The requested page has been temporarily moved to a new url.
4xx: Client error
400 Bad Request
The server failed to understand the request.
401 UnauthorizedThe requested page requires a username and password.
402 Payment Required
This code is not yet available.
403 Forbidden
Access to the requested page is forbidden.
404 Not Found
The server cannot find the requested page.
405 Method Not Allowed
The method specified in the request is not allowed.
406 Not AcceptableThe response generated by the server cannot be accepted by the client.
407 Proxy Authentication RequiredThe user must first authenticate with the proxy server before the request can be processed.
408 Request TimeoutThe request exceeded the server's wait time.
409 Conflict由于冲突，请求无法被完成。
410 Gone被请求的页面不可用。
411 Length Required"Content-Length" 未被定义。如果无此内容，服务器不会接受请求。
412 Precondition Failed请求中的前提条件被服务器评估为失败。
413 Request Entity Too Large由于所请求的实体的太大，服务器不会接受请求。
414 Request-url Too Long由于url太长，服务器不会接受请求。当post请求被转换为带有很长的查询信息的get请求时，就会发生这种情况。
415 Unsupported Media Type由于媒介类型不被支持，服务器不会接受请求。
416 Requested Range Not Satisfiable服务器不能满足客户在请求中指定的Range头。
417 Expectation Failed执行失败。
423锁定的错误。
5xx:服务器错误
500 Internal Server Error
请求未完成。服务器遇到不可预知的情况。
501 Not Implemented
请求未完成。服务器不支持所请求的功能。
502 Bad Gateway请求未完成。服务器从上游服务器收到一个无效的响应。
503 Service Unavailable
请求未完成。服务器临时过载或当机。
504 Gateway Timeout网关超时。
505 HTTP Version Not Supported服务器不支持请求中指明的HTTP协议版本