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    HEAD Object

    Last updated: 2021-11-25 14:28:49
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      Overview

      This API is used to determine whether an object exists and whether you have permission to access it. You can use this API to get the object metadata if you can access it. To call this API, you need to have permission to read the object, or the object is set to public-read (i.e., everyone can read it).

      API Explorer is recommended.
      Debug
      API Explorer makes it easy to make online API calls, verify signatures, generate SDK code, search for APIs, etc. You can also use it to query the content of each request as well as its response.

      Versioning

      With versioning enabled, you can specify the versionId request parameter to get the metadata of an object of a specified version. If the version ID you specify corresponds to a delete marker, HTTP status code “404 (Not Found)” will be returned. If no version ID is specified, the metadata of the latest version will be returned.

      Request

      Sample request

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

      Request parameters

      Parameter Description Type Required
      versionId Specifies the version ID of the object if versioning is enabled; if this parameter is not specified, the latest version will be queried string No

      Request headers

      In addition to common request headers, this API also supports the following request headers. For more information about common request headers, please see Common Request Headers.

      Header Description Type Required
      If-Modified-Since If the object is modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned. string No
      If-Unmodified-Since If the object is not modified after the specified time, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned. string No
      If-Match If the ETag of the object is the same as the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “412 (Precondition Failed)” will be returned. string No
      If-None-Match If the ETag of the object is different from the specified value, HTTP status code 200 (OK) will be returned. Otherwise, “304 (Not Modified)” will be returned. string No

      Server-side encryption headers

      If server-side encryption is used for the specified object and the encryption method is SSE-C, you will need to specify the headers related to server-side encryption to decrypt the object. For more information, see Server-side Encryption Headers.

      Request body

      This API does not have a request body.

      Response

      Response headers

      In addition to common response headers, this API also returns the following response headers. For more information about common response headers, please see Common Response Headers.

      Header Description Type
      Cache-Control Cache directives as defined in RFC 2616, which will be returned only if it is contained in the object metadata string
      Content-Disposition Filename as defined in RFC 2616, which will be returned only if it is contained in the object metadata String
      Content-Encoding Encoding format as defined in RFC 2616, which will be returned only if it is contained in the object metadata string
      Expires Cache expiration time as defined in RFC 2616, which will be returned only if it is contained in the object metadata string
      x-cos-meta-* Contains user-defined metadata and header suffixes string
      x-cos-storage-class Object storage class. For the enumerated values, such as INTELLIGENT_TIERING, STANDARD_IA, ARCHIVE, and DEEP_ARCHIVE, please see Storage Class Overview. Note that this header will be returned only if the object’s storage class is not STANDARD. enum
      x-cos-storage-tier Specifies the access tier of INTELLIGENT TIERING objects. Valid values: FREQUENT, INFREQUENT enum

      Archived object−related headers

      If the storage class of the object is ARCHIVE and POST Object restore has been called to restore it, the following response headers will be returned:

      Header Description Type
      x-cos-restore Indicates the status of the restoration process:
    • If the restoration is ongoing, the value of the response header will be ongoing-request="true"
    • If the object has already been restored, the response header will include the time when COS will delete the temporary copy, e.g., ongoing-request="false", expiry-date="Tue, 19 Nov 2019 16:00:00 GMT"
      		•  string
      x-cos-restore-status This parameter will be returned if the restoration is ongoing, indicating what restoration mode was used and when the restoration was requested, e.g., tier="bulk"; request-date="Mon, 18 Nov 2019 09:34:50 GMT". For more information on restoration modes, see POST Object restore string

      Versioning-related headers

      If the target object is from a versioning-enabled bucket, the following response header will be returned:

      Header Description Type
      x-cos-version-id Object version ID string

      Server-side encryption headers

      If server-side encryption is used for the specified object, this API will return the server-side encryption headers. For more information, see Server-side Encryption Headers.

      Response body

      The response body of this API is empty.

      Error codes

      This API returns common error responses and error codes. For more information, please see Error Codes.

      Examples

      Example 1: simple use case (with versioning disabled)

      Request

      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

      Response

      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****

      Example 2: specifying search criteria through the request headers with HTTP status code 304 (Not Modified) returned

      Request

      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

      Response

      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****

      Example 3: specifying search criteria through the request header with HTTP status code 412 (Precondition Failed) returned

      Request

      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

      Response

      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****

      Example 4: using server-side encryption SSE-COS

      Request

      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

      Response

      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

      Example 5: using server-side encryption SSE-KMS

      Request

      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

      Response

      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****

      Example 6: using server-side encryption SSE-C

      Request

      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

      Response

      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****

      Example 7: requesting the latest version of an object (with versioning enabled)

      Request

      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

      Response

      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

      Example 8: requesting a specific version of an object (with versioning enabled)

      Request

      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

      Response

      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

      Example 9: requesting an archived object that is being restored

      Request

      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

      Response

      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

      Example 10: requesting an archived object which has been restored

      Request

      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

      Response

      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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