HEAD Object
描述：使用HEAD请求方式获取Object的Metadata。
请求格式：
HEAD /<ObjectName> HTTP/1.1
Host: <Your-Bucket-Name>.ss.bscstorage.com
Date: <date>
Authorization: <authorization string> #请参照《签名算法》
- 响应（无HTTP Body）：
HTTP/1.1 200 OK
Date: Tue, 08 Apr 2014 02:59:47 GMT
Connection: keep-alive
Content-Type: <object-mime-type>
Content-Length: <object-file-bytes>
ETag: "<文件的MD5值>"
Last-Modified: <最后修改时间>
x-amz-request-id: 0000106c-1608-0810-4621-00163e000064
x-amz-s2-requester: <Your UserName>
x-amz-meta-foo1: <value1> #自定义meta：foo1
x-amz-meta-foo2: <value2> #自定义meta：foo2
- Request Headers（请求头）：
| Name | Description | Required |
|---|---|---|
| Range |
Downloads the specified range bytes of an object. For more information about the HTTP Range header, go to http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35. • Type: String • Default: None • Constraints: None |
No |
| If-Modified-Since |
Return the object only if it has been modified since the specified time, otherwise return a 304 (not modified). • Type: String • Default: None • Constraints: None |
No |
| If-Unmodified-Since |
Return the object only if it has not been modified since the specified time, otherwise return a 412 (precondition failed). • Type: String • Default: None • Constraints: None |
No |
| If-Match |
Return the object only if its entity tag (ETag) is the same as the one specified; otherwise, return a 412 (precondition failed). • Type: String • Default: None • Constraints: None |
No |
| If-None-Match |
Return the object only if its entity tag (ETag) is different from the one specified; otherwise, return a 304 (not modified). • Type: String • Default: None • Constraints: None |
No |
- Response Headers（响应头）：
| Name | Description |
|---|---|
| Content-Type | Object的mime-type |
| Content-Length | Object的Size(bytes) |
| ETag | Object的hash值，一般是md5值 |
| Last-Modified | Object的最后修改时间 |
| x-amz-meta-* | 用户可自定义文件属性信息，读取时原值返回。 例如： x-amz-meta-UploadLocation: My Home X-amz-meta-ReviewedBy: test@test.net X-amz-meta-FileChecksum: 0x02661779 X-amz-meta-CheckSumAlgorithm: crc32 |
| x-amz-meta-crc32 | Object的CRC32值 |
- 请求示例：
curl -v -X HEAD -H "Date: Sat, 20 Nov 2286 17:46:39 GMT" -H "Authorization: AWS <access_key>:<ssig>" "http://<Your-Bucket-Name>.ss.bscstorage.com/<Object-Name>"