Updated on 2023-11-09 GMT+08:00

GET Object

API Description

You can user this API to download an object in a specified bucket.

Method

ObsClient.getObject

Request Parameters

Field

Type

Optional or Mandatory

Description

Bucket

String

Mandatory

Bucket name

Key

String

Mandatory

Object name

VersionId

String

Optional

Object version ID

ProgressCallback

Function

Optional

Callback function for obtaining the download progress

NOTE:

This callback function contains the following parameters in sequence: number of downloaded bytes, total bytes, and used time (unit: second).

IfMatch

String

Optional

Returns the source object if its ETag is the same as the one specified by this parameter; otherwise, an error code is returned.

IfModifiedSince

String

Optional

Returns the object if it is modified after the time specified by this parameter; otherwise, an error code is returned. This parameter must conform with the HTTP time format specified in http://www.ietf.org/rfc/rfc2616.txt.

IfNoneMatch

String

Optional

Returns the source object if its ETag is different from the one specified by this parameter; otherwise, an error code is returned.

IfUnmodifiedSince

String

Optional

Returns the object if it remains unchanged since the time specified by this parameter; otherwise, an error code is returned. This parameter must conform with the HTTP time format specified in http://www.ietf.org/rfc/rfc2616.txt.

Range

String

Optional

Download range. The value range is [0, object length-1] and is in the format of bytes=x-y. The maximum length of Range is the length of the object minus 1. If it exceeds this value, the length of the object minus 1 is used.

Origin

String

Optional

Origin of the cross-domain request specified by the pre-request. Generally, it is a domain name.

RequestHeader

String

Optional

HTTP headers in the cross-domain request

ResponseCacheControl

String

Optional

Rewrites the Cache-Control header in the response.

ResponseContentDisposition

String

Optional

Rewrites the Content-Disposition header in the response.

ResponseContentEncoding

String

Optional

Rewrites the Content-Encoding header in the response.

ResponseContentLanguage

String

Optional

Rewrites the Content-Language header in the response.

ResponseContentType

String

Optional

Rewrites the Content-Type header in the response.

ResponseExpires

String

Optional

Rewrites the Expires header in the response

SaveAsFile

String

Optional

The download path with the file name contained

SaveAsStream

Boolean

Optional

Whether the object is returned as a readable stream

SseC

String

Optional

Algorithm used in SSE-C decryption. The value can be:

  • AES256

SseCKey

Buffer

Optional

Key used in SSE-C decryption, which is calculated by using AES256.

  • SaveAsFile and SaveAsStream cannot be used together.
  • If the download request includes IfUnmodifiedSince or IfMatch, and IfUnmodifiedSince or IfMatch is not met, 412 Precondition Failed will be returned.
  • If the download request includes IfModifiedSince or IfNoneMatch, and IfModifiedSince or IfNoneMatch is not met, 304 Not Modified will be returned.

Returned Result (InterfaceResult)

Field

Type

Description

RequestId

String

Request ID returned by the OBS server

DeleteMarker

String

Whether the deleted object is a delete marker

LastModified

String

Time when the last modification was made to the object

ContentLength

String

Object size in bytes

CacheControl

String

Cache-Control header in the response

ContentDisposition

String

Content-Disposition header in the response

ContentEncoding

String

Content-Encoding header in the response

ContentLanguage

String

Content-Language header in the response

ContentType

String

MIME type of the object

Expires

String

Expires header in the response

ETag

String

Object ETag

VersionId

String

Object version ID

WebsiteRedirectLocation

String

Location where the object is redirected to, when the bucket is configured with website hosting

StorageClass

String

Storage class of the object. When the storage class is OBS Standard, the value is null.

Restore

String

Restore status of the object in the OBS Archive storage class

AllowOrigin

String

If Origin in the request meets the CORS rules of the bucket, AllowedOrigin in the CORS rules is returned.

AllowHeader

String

If RequestHeader in the request meets the CORS rules of the bucket, AllowedHeader in the CORS rules is returned.

AllowMethod

String

AllowedMethod in the CORS rules of the bucket

ExposeHeader

String

ExposeHeader in the CORS rules of the bucket

MaxAgeSeconds

String

MaxAgeSeconds in the CORS rules of the bucket

SseKms

String

Algorithm used in SSE-KMS decryption

SseKmsKey

String

Master key used in SSE-KMS decryption

SseC

String

Algorithm used in SSE-C decryption

SseCKeyMd5

String

MD5 value of the key used in SSE-C decryption

Expiration

String

Expiration details

Content

String or stream.Readable

Content of the object. The content is null when SaveAsFile is set. The content is an instance of stream.Readable when SaveAsStream is set to true. The content is an instance of Buffer when neither SaveAsFile nor SaveAsStream is set.

Metadata

Object

Customized metadata of the object

Sample Code

This example downloads part (length range: 0-1,023 bytes) of objectname from examplebucket and prints the progress.

// Use npm to install the client.
var ObsClient = require('esdk-obs-nodejs');

// Obtain an AK/SK pair using environment variables or import the AK/SK pair in other ways. Using hard coding may result in leakage.
// Obtain an AK/SK pair on the management console by referring to https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
const AK = process.env.AccessKeyID
const SK = process.env.SecretAccessKey
// (Optional) If you use a temporary AK/SK pair and a security token to access OBS, obtain them using environment variables.
const security_token= process.env.SecurityToken
// Set server to the endpoint corresponding to the bucket. EU-Dublin is used here as an example. Replace it with the one in your actual situation.
const server = "https://obs.eu-west-101.myhuaweicloud.com"

var obsClient = new ObsClient({
    access_key_id: AK,
    secret_access_key: SK,
    server: server,
});
const Bucket = 'examplebucket'
// Name of the object to be downloaded
const Key = 'objectname'
// Specify the object range to download in the format of bytes=x-y. The range must be from 0 to the total bytes of the object minus 1. If the specified range is beyond the allowed upper limit, the upper limit is used.
const Range = 'bytes=0-1023'
// Specify the download path with the file name contained.
const SaveAsFile = 'D:\\example'
try {
    obsClient.getObject({
        Bucket,
        Key,
        Range,
        SaveAsFile,
        // Progress callback
        ProgressCallback: function (transferredAmount, totalAmount, totalSeconds) {
            // Print the download speed in KB/s.
            console.log(transferredAmount * 1.0 / totalSeconds / 1024);
            // Print the upload percentage.
            console.log(transferredAmount * 100.0 / totalAmount);
        },
        // Specify whether to return the object as a readable stream.
        // SaveAsStream: true
    }, (err, result) => {
        if (err) {
            console.log('GetObject Failed')
            console.error('Error-->' + err);
        } else {
            if (result.CommonMsg.Status < 300) {
                console.log('GetObject Succeeded')
                console.log('RequestId-->' + result.InterfaceResult.RequestId);
                console.log('ETag-->' + result.InterfaceResult.ETag);
                // The following parameters are exclusive to versioned objects.
                console.log('VersionId-->' + result.InterfaceResult.VersionId);
                console.log('ContentLength-->' + result.InterfaceResult.ContentLength);
                // The following parameters are exclusive to versioned objects.
                console.log('DeleteMarker-->' + result.InterfaceResult.DeleteMarker);
                console.log('LastModified-->' + result.InterfaceResult.LastModified);
                // Object storage class. If the storage class is Standard, this parameter is left blank.
                console.log('StorageClass-->' + result.InterfaceResult.StorageClass);
                // console.log('Content-->' + result.InterfaceResult.Content.toString());
                console.log('Metadata-->' + JSON.stringify(result.InterfaceResult.Metadata));
            } else {
                console.log('GetObject Failed')
                console.log('ErrorCode-->' + result.CommonMsg.Code);
                console.log('ErrorMessage-->' + result.CommonMsg.Message);
            }
        }
    });
} catch (error) {
    console.log('GetObject Failed')
    console.error('Error-->' + error);
}