前言：摘抄自Laravel框架的resopn类中。

100 => 'Continue',101 => 'Switching Protocols',102 => 'Processing', // RFC2518103 => 'Early Hints',200 => 'OK',201 => 'Created',202 => 'Accepted',203 => 'Non-Authoritative Information',204 => 'No Content',205 => 'Reset Content',206 => 'Partial Content',207 => 'Multi-Status', // RFC4918208 => 'Already Reported', // RFC5842226 => 'IM Used', // RFC3229300 => 'Multiple Choices',301 => 'Moved Permanently',302 => 'Found',303 => 'See Other',304 => 'Not Modified',305 => 'Use Proxy',307 => 'Temporary Redirect',308 => 'Permanent Redirect', // RFC7238400 => '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', // RFC2324421 => 'Misdirected Request', // RFC7540422 => 'Unprocessable Entity', // RFC4918423 => 'Locked', // RFC4918424 => 'Failed Dependency', // RFC4918425 => 'Reserved for WebDAV advanced collections expired proposal', // RFC2817426 => 'Upgrade Required', // RFC2817428 => 'Precondition Required', // RFC6585429 => 'Too Many Requests', // RFC6585431 => 'Request Header Fields Too Large', // RFC6585451 => 'Unavailable For Legal Reasons', // RFC7725500 => 'Internal Server Error',501 => 'Not Implemented',502 => 'Bad Gateway',503 => 'Service Unavailable',504 => 'Gateway Timeout',505 => 'HTTP Version Not Supported',506 => 'Variant Also Negotiates', // RFC2295507 => 'Insufficient Storage', // RFC4918508 => 'Loop Detected', // RFC5842510 => 'Not Extended', // RFC2774511 => 'Network Authentication Required',