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HEAD Object

Last updated: 2024-09-27 19:12:21

    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).
    

    Authorization Description

    In the authorization policy, set action to cos:HeadObject. View all actions.

    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:
    Host:<BucketName-APPID>.cos.<Region>.myqcloud.com, where <BucketName-APPID> is the is the bucket name followed by the APPID, such as examplebucket-1250000000 (see Bucket Overview > Basic Information and Bucket Overview > Bucket Naming Conventions), and <Region> is a COS region (see Regions and Access Endpoints).
    Authorization: Auth String (See Request Signature for details.)

    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
    ARCHIVE_ACCESS
    DEEP_ARCHIVE_ACCESS
    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 response header will be returned if the restoration is ongoing, indicating the current restoration mode, the request time of the restoration and the expected completion time of restoration. tier="standard"; request-date="Mon, 18 Nov 2019 09:34:50 GMT";expect-restore-date="Fri, 27 Dec 2019 08:20:00 GMT"For more information on restoration modes, see POST Object restore
    Note:
    Only archive-type objects support displaying the expected completion time of restoration. Deep archive objects do not support displaying the expected completion time of restoration.
    
    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.
    Bucket replication-related headers
    If the object is the source or target object of bucket replication, the following response headers will be returned.
    Name
    Description
    Type
    x-cos-replication-status
    Current replication status. The source object shows Pending, Failed, or Complete. The target object shows Replica.
    string

    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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