Updated on 2024-06-21 GMT+08:00

Modifying an Object (SDK for Go)

Function

This API modifies the content of an object in a parallel file system from the specified position.

Restrictions

Method

func (obsClient ObsClient) ModifyObject(input *ModifyObjectInput) (output *ModifyObjectOutput, err error)

Request Parameters

Table 1 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

input

*ModifyObjectInput

Yes

Explanation:

Input parameters for modifying an object. For details, see Table 2.

Table 2 ModifyObjectInput

Parameter

Type

Mandatory (Yes/No)

Description

Bucket

string

Yes

Explanation:

Bucket name

Restrictions:

  • A bucket name must be unique across all accounts and regions.
  • A bucket name:
    • Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed.
    • Cannot be formatted as an IP address.
    • Cannot start or end with a hyphen (-) or period (.).
    • Cannot contain two consecutive periods (..), for example, my..bucket.
    • Cannot contain a period (.) and a hyphen (-) adjacent to each other, for example, my-.bucket or my.-bucket.
  • If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request.

Default value:

None

Key

string

Yes

Explanation:

Object name. An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name.

For example, if the address for accessing the object is examplebucket.obs.eu-west-101.myhuaweicloud.com/folder/test.txt, the object name is folder/test.txt.

Value range:

The value must contain 1 to 1,024 characters.

Default value:

None

Position

int64

Yes

Explanation:

Position from which the object is modified

Value range:

1 to (263 – 1), in bytes

Default value:

1, indicating the modification starts from the first byte of the object

ContentLength

int64

No

Explanation:

Size of the object to be modified

Value range:

1 to (263 – 1), in bytes

Default value:

None

Body

io.Reader

No

Explanation:

Data stream of the object to be modified

Default value:

None

Responses

Table 3 List of returned results

Parameter

Type

Description

output

*ModifyObjectOutput

Explanation:

Returned results. For details, see Table 4.

err

error

Explanation:

Error messages returned by the API

Table 4 ModifyObjectOutput

Parameter

Type

Description

StatusCode

int

Explanation:

HTTP status code

Value range:

A status code is a group of digits that can be 2xx (indicating successes) or 4xx or 5xx (indicating errors). It indicates the status of a response. For more information, see Status Code.

Default value:

None

RequestId

string

Explanation:

Request ID returned by the OBS server

Default value:

None

ResponseHeaders

map[string][]string

Explanation:

HTTP response headers

Default value:

None

ETag

string

Explanation:

Base64-encoded, 128-bit MD5 value of an object. ETag is the unique identifier of the object content. It can be used to determine whether the object content is changed. For example, if the ETag value is A when an object is uploaded, but changes to B when the object is downloaded, it indicates that the object content has been changed. The ETag reflects changes to the object content, rather than the object metadata. An uploaded or copied object has a unique ETag after being encrypted using MD5.

Restrictions:

If an object is encrypted using server-side encryption, the ETag is not the MD5 value of the object.

Value range:

The value must contain 32 characters.

Default value:

None

Code Examples

This example modifies object example/objectname in bucket examplebucket.

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package main
import (
    "fmt"
    "os"
    "strings"
    obs "github.com/huaweicloud/huaweicloud-sdk-go-obs/obs"
)
func main() {
    //Obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways. Using hard coding may result in leakage.
    //Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
    ak := os.Getenv("AccessKeyID")
    sk := os.Getenv("SecretAccessKey")
    // (Optional) If you use a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding to reduce leakage risks. You can obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways.
    // securityToken := os.Getenv("SecurityToken")
    // Enter the endpoint corresponding to the bucket. EU-Dublin is used here as an example. Replace it with the one currently in use.
    endPoint := "https://obs.eu-west-101.myhuaweicloud.eu" 
    // Create an obsClient instance.
    // If you use a temporary AK/SK pair and a security token to access OBS, use the obs.WithSecurityToken method to specify a security token when creating an instance.
    obsClient, err := obs.New(ak, sk, endPoint/*, obs.WithSecurityToken(securityToken)*/)
    if err != nil {
        fmt.Printf("Create obsClient error, errMsg: %s", err.Error())
    }
    input := &obs.ModifyObjectInput{}
    // Specify a bucket name.
    input.Bucket = "examplebucket"
    // Specify an object (example/objectname as an example).
    input.Key = "example/objectname"
    input.Position = 0
    input.Body = strings.NewReader("Modify Hello OBS")
    // Modify the object.
    output, err := obsClient.ModifyObject(input)
    if err == nil {
        fmt.Printf("Modify object(%s) under the bucket(%s) successful!\n", input.Key, input.Bucket)
        fmt.Printf("ETag:%s\n", output.ETag)
        return
    }
    fmt.Printf("Modify object(%s) under the bucket(%s) fail!\n", input.Key, input.Bucket)
    if obsError, ok := err.(obs.ObsError); ok {
        fmt.Println("An ObsError was found, which means your request sent to OBS was rejected with an error response.")
        fmt.Println(obsError.Error())
    } else {
        fmt.Println("An Exception was found, which means the client encountered an internal problem when attempting to communicate with OBS, for example, the client was unable to access the network.")
        fmt.Println(err)
    }
}