HEAD Object

最后更新时间:2020-11-30 20:10:10

    功能描述

    HEAD Object 接口请求可以判断指定对象是否存在和有权限,并在指定对象可访问时获取其元数据。该 API 的请求者需要对目标对象有读取权限,或者目标对象向所有人开放了读取权限(公有读)。

    版本控制

    当启用版本控制时,该 HEAD 操作可以使用 versionId 请求参数指定要返回的版本 ID,此时将返回指定版本的元数据,如指定版本为删除标记则返回 HTTP 响应码404(Not Found),否则将返回最新版本的元数据。

    请求

    请求示例

    HEAD /<ObjectKey> HTTP/1.1
    Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
    Date: GMT Date
    Authorization: Auth String

    Authorization: Auth String (详情请参见 请求签名 文档)。

    请求参数

    名称 描述 类型 是否必选
    versionId 当启用版本控制时,指定要查询的版本 ID,如不指定则查询对象的最新版本 string

    请求头

    此接口除使用公共请求头部外,还支持以下请求头部,了解公共请求头部详情请参见 公共请求头部 文档。

    名称                            描述 类型 是否必选
    If-Modified-Since 当对象在指定时间后被修改,则返回 HTTP 状态码为200(OK),否则返回 HTTP 状态码为304(Not Modified) string
    If-Unmodified-Since 当对象在指定时间后未被修改,则返回 HTTP 状态码为200(OK),否则返回 HTTP 状态码为412(Precondition Failed) string
    If-Match 当对象的 ETag 与指定的值一致,则返回 HTTP 状态码为200(OK),否则返回 HTTP 状态码为412(Precondition Failed) string
    If-None-Match 当对象的 ETag 与指定的值不一致,则返回 HTTP 状态码为200(OK),否则返回 HTTP 状态码为304(Not Modified) string

    服务端加密相关头部

    如果指定的对象使用了服务端加密且加密方式为 SSE-C 时,则需要指定服务端加密的相关头部来解密对象,请参见 服务端加密专用头部

    请求体

    此接口无请求体。

    响应

    响应头

    此接口除返回公共响应头部外,还返回以下响应头部,了解公共响应头部详情请参见 公共响应头部 文档。

    名称                          描述 类型
    Cache-Control RFC 2616 中定义的缓存指令,仅当对象元数据包含此项时才会返回该头部 string
    Content-Disposition RFC 2616 中定义的文件名称,仅当对象元数据包含此项时才会返回该头部 string
    Content-Encoding RFC 2616 中定义的编码格式,仅当对象元数据包含此项时才会返回该头部 string
    Expires RFC 2616 中定义的缓存失效时间,仅当对象元数据包含此项时才会返回该头部 string
    x-cos-meta-* 包括用户自定义元数据头部后缀和用户自定义元数据信息 string
    x-cos-storage-class 对象存储类型,枚举值请参见 存储类型 文档,例如 MAZ_STANDARD,MAZ_STANDARD_IA,STANDARD_IA,ARCHIVE,DEEP_ARCHIVE。仅当对象不是标准存储(STANDARD)时才会返回该头部 Enum
    x-cos-storage-tier 当对象的存储类型为智能分层存储时,该头部表示对象所处的存储层,有效值:FREQUENT、INFREQUENT。 enum

    归档类型对象相关头部

    当对象为归档类型且使用 POST Object restore 请求进行恢复操作时,该 HEAD 请求将返回下列响应头部:

    名称                           描述 类型
    x-cos-restore 指示当前恢复操作的状态:
  • 当恢复操作正在进行中时,该响应头部的值为ongoing-request="true"
  • 当对象已经恢复时,该响应头部包含 COS 即将删除临时副本的时间,例如ongoing-request="false", expiry-date="Tue, 19 Nov 2019 16:00:00 GMT"
  • string
    x-cos-restore-status 当恢复操作正在进行中时返回该响应头部,指示当前的恢复模式和恢复操作请求时间,例如tier="bulk"; request-date="Mon, 18 Nov 2019 09:34:50 GMT",有关恢复模式请参见 POST Object restore string

    版本控制相关头部

    启用版本控制的存储桶内的对象将返回下列响应头部:

    名称 描述 类型
    x-cos-version-id 对象的版本 ID string

    服务端加密相关头部

    如果指定的对象使用了服务端加密,则此接口将返回服务端加密专用头部,请参见 服务端加密专用头部

    响应体

    此接口响应体为空。

    错误码

    此接口遵循统一的错误响应和错误码,详情请参见 错误码 文档。

    实际案例

    案例一:简单案例(未启用版本控制)

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:17:36 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542656;1586549856&q-key-time=1586542656;1586549856&q-header-list=date;host&q-url-param-list=&q-signature=cde88925e00d1c90ba74985ca43b610bdf6b****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:17:36 GMT
    ETag: "ee8de918d05640145b18f70f4c3aa602"
    Last-Modified: Fri, 10 Apr 2020 18:17:25 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MGI4NDBfNjFjODJhMDlfMzY2NjVfMjNi****

    案例二:通过请求头指定查询条件并返回 HTTP 状态码为304(Not Modified)

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Wed, 29 Jul 2020 06:51:49 GMT
    If-None-Match: "ee8de918d05640145b18f70f4c3aa602"
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1596005509;1596012709&q-key-time=1596005509;1596012709&q-header-list=date;host;if-none-match&q-url-param-list=&q-signature=9d087f05c259ca271efe91fc780cdced75c6****
    Connection: close

    响应

    HTTP/1.1 304 Not Modified
    Content-Type: application/xml
    Content-Length: 0
    Connection: close
    Date: Wed, 29 Jul 2020 06:51:49 GMT
    Server: tencent-cos
    x-cos-request-id: NWYyMTFjODVfZDNjODJhMDlfMWU1MWVfOTUy****
    x-cos-trace-id:  OGVmYzZiMmQzYjA2OWNhODk0NTRkMTBiOWVmMDAxODczNTBmNjMwZmQ0MTZkMjg0NjlkNTYyNmY4ZTRkZTk0NzJmZTI0ZmJhYTZmZjYyNmU5ZGNlZDI5YjkyODkwYjNhZjhlNGQ0MDY1ZGIxNDEwMWYwOTg1NDc4Mzg4MTE3****

    案例三:通过请求头指定查询条件并返回 HTTP 状态码为412(Precondition Failed)

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Wed, 29 Jul 2020 06:51:50 GMT
    If-Match: "aa488bb80185a6be87f4a7b936a80752"
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1596005510;1596012710&q-key-time=1596005510;1596012710&q-header-list=date;host;if-match&q-url-param-list=&q-signature=38afe94fc61ca0b3aa763e00b23fd90ac23e****
    Connection: close

    响应

    HTTP/1.1 412 Precondition Failed
    Content-Type: application/xml
    Content-Length: 0
    Connection: close
    Date: Wed, 29 Jul 2020 06:51:50 GMT
    Server: tencent-cos
    x-cos-request-id: NWYyMTFjODZfMzBjMDJhMDlfMmU3ZF9kYTE4****
    x-cos-trace-id: OGVmYzZiMmQzYjA2OWNhODk0NTRkMTBiOWVmMDAxODczNTBmNjMwZmQ0MTZkMjg0NjlkNTYyNmY4ZTRkZTk0NzJmZTI0ZmJhYTZmZjYyNmU5ZGNlZDI5YjkyODkwYjNhZDRkOWFlZjczOWExNjZmY2RiNjhjNGIwZWQ3YjYw****

    案例四:使用服务端加密 SSE-COS

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:18:19 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542699;1586549899&q-key-time=1586542699;1586549899&q-header-list=date;host&q-url-param-list=&q-signature=6a6d4dd5b5a9e6379f300715985bfb60b947****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:18:19 GMT
    ETag: "ee8de918d05640145b18f70f4c3aa602"
    Last-Modified: Fri, 10 Apr 2020 18:18:08 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MGI4NmJfNmRjMDJhMDlfZGQwNl8xZmE4****
    x-cos-server-side-encryption: AES256

    案例五:使用服务端加密 SSE-KMS

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:18:30 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542710;1586549910&q-key-time=1586542710;1586549910&q-header-list=date;host&q-url-param-list=&q-signature=7c8a1c93b9701e653c2ab00419f976397d00****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:18:30 GMT
    ETag: "00ca268468481b847fc2d8a9bd84578d"
    Last-Modified: Fri, 10 Apr 2020 18:18:19 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MGI4NzZfN2FjODJhMDlfMjU3N18xYTEz****
    x-cos-server-side-encryption: cos/kms
    x-cos-server-side-encryption-cos-kms-key-id: 48ba38aa-26c5-11ea-855c-52540085****

    案例六:使用服务端加密 SSE-C

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:18:41 GMT
    x-cos-server-side-encryption-customer-algorithm: AES256
    x-cos-server-side-encryption-customer-key: MDEyMzQ1Njc4OUFCQ0RFRjAxMjM0NTY3ODlBQkNE****
    x-cos-server-side-encryption-customer-key-MD5: U5L61r7jcwdNvT7frmUG****
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542721;1586549921&q-key-time=1586542721;1586549921&q-header-list=date;host;x-cos-server-side-encryption-customer-algorithm;x-cos-server-side-encryption-customer-key;x-cos-server-side-encryption-customer-key-md5&q-url-param-list=&q-signature=99ad258fc295f43feb0546bb2346c8269dc5****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:18:41 GMT
    ETag: "582d9105f71525f3c161984bc005efb5"
    Last-Modified: Fri, 10 Apr 2020 18:18:31 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MGI4ODFfN2NiODJhMDlfMmFmYTVfMWRh****
    x-cos-server-side-encryption-customer-algorithm: AES256
    x-cos-server-side-encryption-customer-key-MD5: U5L61r7jcwdNvT7frmUG****
    

    案例七:请求对象最新版本(启用版本控制)

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:19:15 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542755;1586549955&q-key-time=1586542755;1586549955&q-header-list=date;host&q-url-param-list=&q-signature=7909dc19780873dfaa51c8b238254098ca1a****
    Connection: close
    

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 26
    Connection: close
    Date: Fri, 10 Apr 2020 18:19:15 GMT
    ETag: "22e024392de860289f0baa7d6cf8a549"
    Last-Modified: Fri, 10 Apr 2020 18:19:04 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 11596229263574363878
    x-cos-request-id: NWU5MGI4YTNfZDZjODJhMDlfYmU0MV8xM2Y5****
    x-cos-version-id: MTg0NDUxNTc1MzA5NjQ2ODI5MTg
    

    案例八:请求对象指定版本(启用版本控制)

    请求

    HEAD /exampleobject?versionId=MTg0NDUxNTc1MzA5NzU4ODg1Mjg HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 10 Apr 2020 18:19:04 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1586542744;1586549944&q-key-time=1586542744;1586549944&q-header-list=date;host&q-url-param-list=versionid&q-signature=1307acd3e8649087c738ecca452a54fa5a79****
    Connection: close
    

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:19:04 GMT
    ETag: "ee8de918d05640145b18f70f4c3aa602"
    Last-Modified: Fri, 10 Apr 2020 18:18:53 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MGI4OThfN2RiNDBiMDlfMTk1MTBfMWZj****
    x-cos-version-id: MTg0NDUxNTc1MzA5NzU4ODg1Mjg

    案例九:归档存储正在恢复中

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Fri, 27 Dec 2019 08:19:35 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1577434775;1577441975&q-key-time=1577434775;1577441975&q-header-list=date;host&q-url-param-list=&q-signature=72408a09a5fc00d77d389559a0cfa5c98e31****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 13
    Connection: close
    Date: Fri, 27 Dec 2019 08:19:35 GMT
    ETag: "b62e10bcab55a88240bd9c436cffdcf9"
    Last-Modified: Fri, 27 Dec 2019 08:19:23 GMT
    Server: tencent-cos
    x-cos-request-id: NWUwNWJlOTdfN2VjODJhMDlfOGI1N18yYjYz****
    x-cos-restore: ongoing-request="true"
    x-cos-restore-status: tier="expedited"; request-date="Fri, 27 Dec 2019 08:19:29 GMT"
    x-cos-storage-class: ARCHIVE

    案例十:归档存储已恢复

    请求

    HEAD /exampleobject HTTP/1.1
    Host: examplebucket-1250000000.cos.ap-beijing.myqcloud.com
    Date: Thu, 02 Jan 2020 18:09:51 GMT
    Authorization: q-sign-algorithm=sha1&q-ak=AKID8A0fBVtYFrNm02oY1g1JQQF0c3JO****&q-sign-time=1577988591;1577995791&q-key-time=1577988591;1577995791&q-header-list=date;host&q-url-param-list=&q-signature=ff23b3a44945f019916450add646e963c29b****
    Connection: close

    响应

    HTTP/1.1 200 OK
    Content-Type: image/jpeg
    Content-Length: 16
    Connection: close
    Date: Fri, 10 Apr 2020 18:17:36 GMT
    ETag: "ee8de918d05640145b18f70f4c3aa602"
    Last-Modified: Fri, 10 Apr 2020 18:17:25 GMT
    Server: tencent-cos
    x-cos-hash-crc64ecma: 16749565679157681890
    x-cos-request-id: NWU5MWRiZjFfMmViMDJhMDlfNjIwOF8zNTU0****
    x-cos-restore: ongoing-request="false", expiry-date="Mon, 13 Apr 2020 16:00:00 GMT"
    x-cos-storage-class: ARCHIVE

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