XMLHTTP中readState与status的状态值

status状态值:

100 Continue

101 Switching protocols

200 OK

201 Created

202 Accepted

203 Non-Authoritative Information

204 No Content

205 Reset Content

206 Partial Content

300 Multiple Choices

301 Moved Permanently

302 Found

303 See Other

304 Not Modified

305 Use Proxy

307 Temporary Redirect

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 Request Entity Too Large

414 Request-URI Too Long

415 Unsupported Media Type

416 Requested Range Not Suitable

417 Expectation Failed

500 Internal Server Error

501 Not Implemented

502 Bad Gateway

503 Service Unavailable

504 Gateway Timeout

505 HTTP Version Not Supported

readyState的状态值

0 (未初始化) 对象已建立，但是尚未初始化（尚未调用open方法）

1 (初始化) 对象已建立，尚未调用send方法

2 (发送数据) send方法已调用，但是当前的状态及http头未知

3 (数据传送中) 已接收部分数据，因为响应及http头不全，这时通过responseBody和responseText获取部分数据会出现错误，

4 (完成) 数据接收完毕,此时可以通过通过responseBody和responseText获取完整的回应数据