Downloading an Object

Functions

This operation downloads an object from OBS. Before using this GET operation, check that you have the read permission for the target object. If the object owner has granted anonymous users the read permission for the object, anonymous users can access this object without using the authentication header field.

Server-Side Encryption

If the object uploaded to the server is encrypted on the server using the encryption key provided by the client, downloading the object requires including the encryption key in the message.

Versioning

By default, the GET operation returns the current version of an object. If the current version of the object is a delete marker, OBS returns a code meaning that the object does not exist. To obtain an object of a specified version, the versionId parameter can be used to specify the desired version.

Cold Objects

If the object you want to download is in the Cold storage class, ensure that this object has been restored before you download it. The response varies depending on the object's restore state. If an object has been restored, the x-obs-restore header (indicating the expiry date of the object) is returned when the object is successfully downloaded. If you send a request to download Cold objects that are not restored or are being restored, a 403 Forbidden error will be returned.

Request Syntax

GET /ObjectName HTTP/1.1
Host: bucketname.obs.region.example.com
Date: date
Authorization: authorization
Range:bytes=byte_range
<Optional Additional Header>

Note

The field is optional. If it does not exist, you can obtain the whole content.

Request Parameters

In a GET request, you can override values for a set of message headers using the request parameters. Message headers that you can override are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. If the target object has multiple versions, use the versionId parameter to specify the version to be downloaded. For details, see Table 1.

Note

OBS does not process Accept-Encoding carried in a request or compress or decompress the uploaded data. The client determines whether to compress or decompress the data. Some HTTP clients may decompress data based on the Content-Encoding returned by the server. The client program needs to determine whether to decompress and how to decompress the data. To decompress the data, it can modify Content-Encoding (the object metadata stored in OBS) or rewrite Content-Encoding the object is downloaded. If an object download request specifies the rewrite header, the standard HTTP message header returned by OBS is subject to the rewrite content specified in the request.

Table 1 Request parameters

Parameter

Description

Mandatory

response-content-type

Rewrites the Content-Type header in the response.

Type: string

No

response-content-language

Rewrites the Content-Language header in the response.

Type: string

No

response-expires

Rewrites the Expires header in the response.

Type: string

No

response-cache-control

Rewrites the Cache-Control header in the response.

Type: string

No

response-content-disposition

Rewrites the Content-Disposition header in the response.

Type: string

Example:

response-content-disposition=attachment; filename*=utf-8''name1

In this example, the downloaded object is renamed name1. If the new name contains full-width characters, it must be URL-encoded.

No

response-content-encoding

Rewrites the Content-Encoding header in the response.

Type: string

No

versionId

Indicates the version ID of the object whose content is obtained.

Type: string

No

attname

Rewrites the Content-Disposition header in the response.

Type: string

Example:

attname=name1

Rename the downloaded object as name1.

No

Request Headers

This request uses common headers. In addition, you can add additional headers to this request. Table 2 describes the additional headers.

Table 2 Request headers

Header

Description

Mandatory

Range

Obtains the object content within the scope defined by Range. If the parameter value is invalid, the entire object is obtained.

Range value starts from 0, and the maximum value equals the object length minus 1. The start value of Range is mandatory. If only the start value is specified, the system obtains the object content from the start value to default maximum value.

After the Range header field is carried, the value of ETag in the response message is the ETag of the object instead of the ETag of the object in the Range field.

Type: string

bytes=byte_range

Example 1: bytes=0-4

Example 2: bytes=1024

Example 3: bytes=10-20, 30-40 (multiple ranges)

No

If-Modified-Since

Returns the object only if it has been modified since the time specified by this header. Otherwise, 304 Not Modified is returned.

Type: HTTP time character string complying with the format specified at http://www.ietf.org/rfc/rfc2616.txt

No

If-Unmodified-Since

Returns the object only if it has not been modified since the time specified by this header. Otherwise, 412 Precondition Failed is returned.

Type: HTTP time character string complying with the format specified at http://www.ietf.org/rfc/rfc2616.txt

No

If-Match

Returns the object only if its ETag is the same as the one specified by this header. Otherwise, 412 Precondition Failed is returned.

Type: string

ETag example: 0f64741bf7cb1089e988e4585d0d3434

No

If-None-Match

Returns the object only if its ETag is different from the one specified by this header. Otherwise, 304 Not Modified is returned.

Type: string

ETag example: 0f64741bf7cb1089e988e4585d0d3434

No

x-obs-server-side-encryption-customer-algorithm

Indicates the encryption algorithm when SSE-C is used.

Type: string

Example: x-obs-server-side-encryption-customer-algorithm:AES256

Constraint: This header must be used together with x-obs-server-side-encryption-customer-key and x-obs-server-side-encryption-customer-key-MD5.

No. This header is required when SSE-C is used.

x-obs-server-side-encryption-customer-key

Indicates the key for decrypting objects when SSE-C is used.

Type: string

Example: x-obs-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=

Constraint: This header is a Base64-encoded 256-bit key and must be used together with x-obs-server-side-encryption-customer-algorithm and x-obs-server-side-encryption-customer-key-MD5.

No. This header is required when SSE-C is used.

x-obs-server-side-encryption-customer-key-MD5

Indicates the MD5 value of the encryption key when SSE-C is used. The MD5 value is used to check whether any error occurs during the transmission of the key.

Type: string

Example: x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==

Constraint: This header is a Base64-encoded 128-bit MD5 value and must be used together with x-obs-server-side-encryption-customer-algorithm and x-obs-server-side-encryption-customer-key.

No. This header is required when SSE-C is used.

Request Elements

This request involves no elements.

Response Syntax

HTTP/1.1 status_code
Content-Type: type
Date: date
Content-Length: length
Etag: etag
Last-Modified: time

<Object Content>

Response Headers

The response to the request uses common headers. For details, see Table 1.

In addition to the common response headers, the headers listed in Table 3 may be used.

Table 3 Additional response headers

Header

Description

x-obs-expiration

When an object has its lifecycle rule, the object expiration time is subject to its lifecycle rule. This header field is use expiry-date to describe the object expiration date. If the lifecycle rule is configured only for the entire bucket not individual objects, the object expiration time is subject to the bucket lifecycle rule. This header field uses the expiry-date and rule-id to describe the detailed expiration information of objects. If no lifecycle rule is configured, this header field is not contained in the response.

Type: string

x-obs-website-redirect-location

Indicates the redirected-to location. If the bucket is configured with website information, this parameter can be set for the object metadata so that the website endpoint will evaluate the request for the object as a 301 redirect to another object in the same bucket or an external URL.

Type: string

x-obs-delete-marker

Indicates whether an object is a delete marker. If the object is not marked as deleted, the response does not contain this header.

Type: boolean

Value options: true, false

The default value is false.

x-obs-version-id

Object version ID. If the object has no version number specified, the response does not contain this header.

Valid value: string

Default value: none

x-obs-server-side-encryption

This header is included in a response if SSE-KMS is used.

Type: string

Example: x-obs-server-side-encryption:kms

x-obs-server-side-encryption-kms-key-id

Indicates the master key ID. This header is included in a response when SSE-KMS is used.

Type: string

Format: regionID:domainID:key/key_id

regionID indicates the ID of the region where the key belongs. domainID indicates the ID of the tenant where the key belongs. key_id indicates the key ID used in this encryption.

Example: x-obs-server-side-encryption-kms-key-id:region:domainiddomainiddomainiddoma0001:key/4f1cd4de-ab64-4807-920a-47fc42e7f0d0

x-obs-server-side-encryption-customer-algorithm

Indicates a decryption algorithm. This header is included in a response if SSE-C is used.

Type: string

Example: x-obs-server-side-encryption-customer-algorithm:AES256

x-obs-server-side-encryption-customer-key-MD5

Indicates the MD5 value of a key used to decrypt objects. This header is included in a response if SSE-C is used.

Type: string

Example: x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==

x-obs-object-type

If the object is not a normal one, this header field is returned. The value can be Appendable.

Type: string

x-obs-next-append-position

This header field is returned when the object is an appendable object.

Type: integer

Response Elements

This response contains no elements.

Error Responses

No special error responses are returned. For details about error responses, see Table 2.

Sample Request: Downloading an Object

GET /object01 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 04:24:33 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:NxtSMS0jaVxlLnxlO9awaMTn47s=

Sample Response: Downloading an Object

HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 8DF400000163D3F2A89604C49ABEE55E
Accept-Ranges: bytes
ETag: "3b46eaf02d3b6b1206078bb86a7b7013"
Last-Modified: WED, 01 Jul 2015 01:20:29 GMT
Content-Type: binary/octet-stream
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSQwxJ2I1VvxD/Xgwuw2G2RQax30gdXU
Date: WED, 01 Jul 2015 04:24:33 GMT
Content-Length: 4572

[4572 Bytes object content]

Sample Request: Downloading a Specified Range of an Object

Download the specified range of an object (download a range of an object).

GET /object01 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: Mon, 14 Sep 2020 09:59:04 GMT
Range:bytes=20-30
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:mNPLWQMDWg30PTkAWiqJaLl3ALg=

Download the specified range of an object (download multiple ranges of an object).

GET /object01 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: Mon, 14 Sep 2020 10:02:43 GMT
Range:bytes=20-30,40-50
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:ZwM7Vk2d7sD9o8zRsRKehgKQDkk=

Sample Response: Downloading a Specified Range of an Object

Download the specified range of an object (download a range of an object).

HTTP/1.1 206 Partial Content
Server: OBS
x-obs-request-id: 000001748C0DBC35802E360C9E869F31
Accept-Ranges: bytes
ETag: "2200446c2082f27ed2a569601ca4e360"
Last-Modified: Mon, 14 Sep 2020 01:16:20 GMT
Content-Range: bytes 20-30/4583
Content-Type: binary/octet-stream
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSn2JHu4okx9NBRNZAvBGawa3lt3g31g
Date: Mon, 14 Sep 2020 09:59:04 GMT
Content-Length: 11

[ 11 Bytes object content]

Download the specified range of an object (download multiple ranges of an object).

HTTP/1.1 206 Partial Content
Server: OBS
x-obs-request-id: 8DF400000163D3F2A89604C49ABEE55E
Accept-Ranges: bytes
ETag: "2200446c2082f27ed2a569601ca4e360"
Last-Modified: Mon, 14 Sep 2020 01:16:20 GMT
Content-Type: multipart/byteranges;boundary=35bcf444-e65f-4c76-9430-7e4a68dd3d26
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSIBWFOVW8eeWujkqSnoIANC2mNR1cdF
Date: Mon, 14 Sep 2020 10:02:43 GMT
Content-Length: 288

--35bcf444-e65f-4c76-9430-7e4a68dd3d26
Content-type: binary/octet-stream
Content-range: bytes 20-30/4583
[ 11 Bytes object content]
--35bcf444-e65f-4c76-9430-7e4a68dd3d26
Content-type: binary/octet-stream
Content-range: bytes 40-50/4583
[ 11 Bytes object content]
--35bcf444-e65f-4c76-9430-7e4a68dd3d26

Sample Request: Checking the ETag Value of an Object

Download an object if its ETag value is matched.

GET /object01 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 04:24:33 GMT
If-Match: 682e760adb130c60c120da3e333a8b09
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:NxtSMS0jaVxlLnxlO9awaMTn47s=

Sample Response: Checking the ETag Value of an Object (ETag Mismatch)

If the object's ETag value is not 682e760adb130c60c120da3e333a8b09, the system displays a download failure message.

HTTP/1.1 412 Precondition Failed
Server: OBS
x-obs-request-id: 8DF400000163D3F2A89604C49ABEE55E
Content-Type: application/xml
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSQwxJ2I1VvxD/Xgwuw2G2RQax30gdXU
Date: WED, 01 Jul 2015 04:20:51 GMT

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Error>
  <Code>PreconditionFailed</Code>
  <Message>At least one of the pre-conditions you specified did not hold</Message>
  <RequestId>8DF400000163D3F2A89604C49ABEE55E</RequestId>
  <HostId>ha0ZGaSKVm+uLOrCXXtx4Qn1aLzvoeblctVXRAqA7pty10mzUUW/yOzFue04lBqu</HostId>
  <Condition>If-Match</Condition>
</Error>

Sample Response: Checking the ETag Value of an Object (ETag Matched)

If the object's ETag value is 682e760adb130c60c120da3e333a8b09, the download is successful.

HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 5DEB00000164A21E1FC826C58F6BA001
Accept-Ranges: bytes
ETag: "682e760adb130c60c120da3e333a8b09"
Last-Modified: Mon, 16 Jul 2015 08:03:34 GMT
Content-Type: application/octet-stream
x-obs-id-2: 32AAAQAAEAABAAAQAAEAABAAAQAAEAABCSbkdml1sLSvKnoHaRcOwRI+6+ustDwk
Date: Mon, 16 Jul 2015 08:04:00 GMT
Content-Length: 8

[ 8 Bytes object content]

Sample Request: Downloading an Object Using a Signed URL

GET /object02?AccessKeyId=H4IPJX0TQTHTHEBQQCEC&Expires=1532688887&Signature=EQmDuOhaLUrzrzRNZxwS72CXeXM%3D HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: Fri, 27 Jul 2018 10:52:31 GMT

Sample Response: Downloading an Object Using a Signed URL

HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 804F00000164DB5E5B7FB908D3BA8E00
ETag: "682e760adb130c60c120da3e333a8b09"
Last-Modified: Mon, 16 Jul 2015 08:03:34 GMT
Content-Type: application/octet-stream
x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCTlpxILjhVK/heKOWIP8Wn2IWmQoerfw
Date: Fri, 27 Jul 2018 10:52:31 GMT
Content-Length: 8

[ 8 Bytes object content]

Sample Request: Downloading an Object and Renaming It (with response-content-disposition Used)

Use the response-content-disposition parameter to download and rename an object.

GET /object01?response-content-disposition=attachment; filename*=utf-8''name1 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 04:24:33 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:NxtSMS0jaVxlLnxlO9awaMTn47s=

Sample Response: Downloading an Object and Renaming It (with response-content-disposition Used)

HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 804F00000164DB5E5B7FB908D3BA8E00
ETag: "682e760adb130c60c120da3e333a8b09"
Last-Modified: Mon, 16 Jul 2015 08:03:34 GMT
Content-Type: application/octet-stream
x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCTlpxILjhVK/heKOWIP8Wn2IWmQoerfw
Date: Fri, 27 Jul 2018 10:52:31 GMT
Content-Length: 8
Content-Disposition: attachment; filename*=utf-8''name1

[ 8 Bytes object content]

Sample Request: Downloading an Object and Renaming It (with attname Used)

Use the attname parameter to download and rename an object.

GET /object01?attname=name1 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: WED, 01 Jul 2015 04:24:33 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:NxtSMS0jaVxlLnxlO9awaMTn47s=

Sample Response: Downloading an Object and Renaming It (with attname Used)

HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 804F00000164DB5E5B7FB908D3BA8E00
ETag: "682e760adb130c60c120da3e333a8b09"
Last-Modified: Mon, 16 Jul 2015 08:03:34 GMT
Content-Type: application/octet-stream
x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCTlpxILjhVK/heKOWIP8Wn2IWmQoerfw
Date: Fri, 27 Jul 2018 10:52:31 GMT
Content-Length: 8
Content-Disposition: attachment; filename*=utf-8''name1

[ 8 Bytes object content]