Help Center/ Object Storage Service/ SDK Reference/ Java/ Versioning (SDK for Java)/ Copying an Object Version (SDK for Java)
Updated on 2024-06-18 GMT+08:00

Copying an Object Version (SDK for Java)

Function

This API copies an object version in a specified bucket.

You can call ObsClient.copyObject to copy an object version by specifying the version ID (versionId).

Restrictions

  • To copy an object, you must be the bucket owner or have the required permission (obs:object:PutObject in IAM or PutObject in a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Configuring an Object Policy.
  • You must have the read permission on the source object.
  • The object copy request carries the information about the source bucket and object to be copied in the header field. The message body cannot be carried.
  • Cross-bucket replication in the same region is supported, but cross-region replication is not supported.
  • An object copy can be up to 5 GB in size. If the source object exceeds 5 GB, you can only perform a multipart copy.
  • If the source object is in the Archive storage class, you must restore it first.

Method

obsClient.copyObject(CopyObjectRequest request)

Request Parameters

Table 1 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

request

CopyObjectRequest

Yes

Explanation:

Request parameters for copying an object. For details, see Table 2.

Table 2 CopyObjectRequest

Parameter

Type

Mandatory (Yes/No)

Description

bucketName

String

Yes

Explanation:

Target 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 periods (.) and hyphens (-) 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

objectKey

String

Yes

Explanation:

Target 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.eu/folder/test.txt, the object name is folder/test.txt.

Value range:

The value must contain 1 to 1,024 characters.

Default value:

None

sseKmsHeader

SseKmsHeader

No

Explanation:

Server-side encryption header used for encrypting the target object. For details, see Table 3.

Default value:

None

sseCHeader

SseCHeader

No

Explanation:

Server-side encryption header used for encrypting the target object. For details, see Table 4.

Default value:

None

acl

AccessControlList

No

Explanation:

ACL that can be pre-defined during the object copy. For details, see Table 8.

Default value:

None

successRedirectLocation

String

No

Explanation:

Address (URL) to which a successfully answered request is redirected.

  • If the value is valid and the request is successful, OBS returns status code 303. Location contains SuccessActionRedirect as well as the bucket name, object name, and object ETag.
  • If the value is invalid, OBS ignores this parameter. In such case, the Location header is the object address, and OBS returns a status code based on whether the operation succeeds or fails.

Default value:

None

sourceBucketName

String

Yes

Explanation:

Name of the source bucket.

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 periods (.) and hyphens (-) 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

sourceObjectKey

String

Yes

Explanation:

Source 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.eu/folder/test.txt, the object name is folder/test.txt.

Value range:

The value must contain 1 to 1,024 characters.

Default value:

None

newObjectMetadata

ObjectMetadata

No

Explanation:

User-defined metadata of the target object. For details, see Table 15.

Restrictions:

newObjectMetadata must be used together with replaceMetadata.

Default value:

None

replaceMetadata

boolean

No

Explanation:

Whether to rewrite the metadata of the source object.

Restrictions:

replaceMetadata must be used together with newObjectMetadata.

Value range:

true: The metadata of the source object is rewritten.

false: The metadata of the source object is not rewritten.

Default value:

None

ifModifiedSince

java.util.Date

No

Explanation:

The source object is copied if it has been modified since the specified time; otherwise, an exception is thrown.

Default value:

None

ifUnmodifiedSince

java.util.Date

No

Explanation:

The source object is copied if it has not been modified since the specified time; otherwise, an exception is thrown.

Default value:

None

ifMatchTag

String

No

Explanation:

Preset ETag. If the ETag of the object to be downloaded is the same as the preset ETag, the object is returned. Otherwise, an error is returned. The ETag of the source object is the MD5 value of it.

Restrictions:

  • If the object copy request includes ifUnmodifiedSince, ifMatchTag, ifModifiedSince, or ifNoneMatchTag, and the specified condition is not met, the copy will fail and an exception will be thrown with HTTP status code 412 precondition failed returned.
  • ifModifiedSince and ifNoneMatchTag can be used together. So do ifUnmodifiedSince and ifMatchTag.

Value range:

The value must contain 32 characters.

Default value:

None

ifNoneMatchTag

String

No

Explanation:

Preset ETag. If the ETag of the object to be downloaded is different from the preset ETag, the object is returned. Otherwise, an error is returned.

Value range:

The value must contain 32 characters.

Default value:

None

versionId

String

No

Explanation:

Version ID of the source object.

Value range:

The value must contain 32 characters.

Default value:

None

sseCHeaderSource

SseCHeader

No

Explanation:

Server-side decryption header used for decrypting the source object. For details, see Table 4.

Default value:

None

Table 3 SseKmsHeader

Parameter

Type

Mandatory (Yes/No)

Description

encryption

ServerEncryption

Yes

Explanation:

SSE-KMS is used for encrypting objects on the server side.

Value range:

kms. For details, see Table 5.

Default value:

None

sseAlgorithm

SSEAlgorithmEnum

No

Explanation:

Encryption algorithm.

Restrictions:

Only KMS is supported.

Value range:

See Table 6.

Default value:

None

kmsKeyId

String

No

Explanation:

ID of the KMS master key when SSE-KMS is used.

Value range:

Valid value formats are as follows:

  1. regionID:domainID:key/key_id
  2. key_id
In the preceding formats:
  • regionID indicates the ID of the region where the key belongs.
  • domainID indicates the ID of the account where the key belongs. To obtain it, see How Do I Get My Account ID and User ID?
  • key_id indicates the ID of the key created on Data Encryption Workshop (DEW).

Default value:

  • If this parameter is not specified, the default master key will be used.
  • If there is no such a default master key, OBS will create one and use it by default.
Table 4 SseCHeader

Parameter

Type

Mandatory (Yes/No)

Description

algorithm

ServerAlgorithm

Yes

Explanation:

SSE-C is used for encrypting objects on the server side.

Value range:

AES256, indicating AES is used to encrypt the object in SSE-C. For details, see Table 7.

Default value:

None

sseAlgorithm

SSEAlgorithmEnum

No

Explanation:

Encryption algorithm.

Restrictions:

Only AES256 is supported.

Value range:

See Table 6.

Default value:

None

sseCKey

byte[]

Yes

Explanation:

Key used for encrypting the object when SSE-C is used, in byte[] format.

Default value:

None

sseCKeyBase64

String

No

Explanation:

Base64-encoded key used for encrypting the object when SSE-C is used.

Default value:

None

Table 5 ServerEncryption

Constant

Default Value

OBS_KMS

kms

Table 6 SSEAlgorithmEnum

Constant

Default Value

KMS

kms

AES256

AES256

Table 7 ServerAlgorithm

Constant

Default Value

AES256

AES256

Table 8 AccessControlList

Parameter

Type

Mandatory (Yes/No)

Description

owner

Owner

No

Explanation:

Bucket owner information. For details, see Table 9.

delivered

boolean

No

Explanation:

Whether the bucket ACL is applied to all objects in the bucket.

Value range:

true: The bucket ACL is applied to all objects in the bucket.

false: The bucket ACL is not applied to any objects in the bucket.

Default value:

false

grants

Set<GrantAndPermission>

No

Explanation:

Grantee information. For details, see Table 10.

Table 9 Owner

Parameter

Type

Mandatory (Yes/No)

Description

id

String

Yes

Explanation:

Account (domain) ID of the bucket owner.

Value range:

To obtain the account ID, see How Do I Get My Account ID and User ID?

Default value:

None

displayName

String

No

Explanation:

Account name of the owner.

Value range:

To obtain the account name, see How Do I Get My Account ID and User ID?

Default value:

None

Table 10 GrantAndPermission

Parameter

Type

Mandatory (Yes/No)

Description

grantee

GranteeInterface

Yes

Explanation:

Grantees (users or user groups). For details, see Table 12.

permission

Permission

Yes

Explanation:

Permissions to grant.

Value range:

See Table 11.

Default value:

None

delivered

boolean

No

Explanation:

Whether the bucket ACL is applied to all objects in the bucket.

Value range:

true: The bucket ACL is applied to all objects in the bucket.

false: The bucket ACL is not applied to any objects in the bucket.

Default value:

false

Table 11 Permission

Constant

Default Value

Description

PERMISSION_READ

READ

Read permission.

A grantee with this permission for a bucket can obtain the list of objects, multipart uploads, bucket metadata, and object versions in the bucket.

A grantee with this permission for an object can obtain the object content and metadata.

PERMISSION_WRITE

WRITE

Write permission.

A grantee with this permission for a bucket can upload, overwrite, and delete any object or part in the bucket.

This permission is not available for objects.

PERMISSION_READ_ACP

READ_ACP

Permission to read an ACL.

A grantee with this permission can obtain the ACL of a bucket or object.

A bucket or object owner has this permission for their bucket or object by default.

PERMISSION_WRITE_ACP

WRITE_ACP

Permission to modify an ACL.

A grantee with this permission can update the ACL of a bucket or object.

A bucket or object owner has this permission for their bucket or object by default.

This permission allows the grantee to change the access control policies, meaning the grantee has full control over a bucket or object.

PERMISSION_FULL_CONTROL

FULL_CONTROL

Full control access, including read and write permissions for a bucket and its ACL, or for an object and its ACL.

A grantee with this permission for a bucket has READ, WRITE, READ_ACP, and WRITE_ACP permissions for the bucket.

A grantee with this permission for an object has READ, WRITE, READ_ACP, and WRITE_ACP permissions for the object.

Table 12 GranteeInterface

Parameter

Type

Mandatory (Yes/No)

Description

CanonicalGrantee

CanonicalGrantee

Yes

Explanation:

Grantee (user) information. For details, see Table 13.

GroupGrantee

GroupGrantee

Yes

Explanation:

Grantee (user group) information.

Value range:

See Table 14.

Default value:

None

Table 13 CanonicalGrantee

Parameter

Type

Mandatory (Yes/No)

Description

grantId

String

Yes if Type is set to GranteeUser

Explanation:

Account (domain) ID of the grantee.

Value range:

To obtain the account ID, see How Do I Get My Account ID and User ID?

Default value:

None

displayName

String

No

Parameter description:

Account name of the grantee.

Value range:

To obtain the account name, see How Do I Get My Account ID and User ID?

Default value:

None

Table 14 GroupGrantee

Constant

Description

ALL_USERS

All users.

AUTHENTICATED_USERS

Authorized users. This constant is deprecated.

LOG_DELIVERY

Log delivery group. This constant is deprecated.

Table 15 ObjectMetadata

Parameter

Type

Mandatory (Yes/No)

Description

contentLength

Long

No

Explanation:

Object size.

Restrictions:

  • The object size in a single upload ranges from 0 to 5 GB.
  • To upload files larger than 5 GB, multipart uploads should be used.

Default value:

If this parameter is not specified, the SDK automatically calculates the size of the object.

contentType

String

No

Explanation:

MIME type of the object file. MIME type is a standard way of describing a data type and is used by the browser to decide how to display data.

Value range:

See What Is Content-Type (MIME)? (Java SDK)

Default value:

If this parameter is not specified, the SDK determines the file type based on the suffix of the object name and assigns a value to the parameter. For example, if the suffix of the object name is .xml, the object is an application/xml file. If the suffix is .html, the object is a text/html file.

contentEncoding

String

No

Explanation:

Content-Encoding header in the response. It specifies which encoding is applied to the object.

Default value:

None

contentDisposition

String

No

Explanation:

Provides a default file name for the requested object. When the object with the default file name is being downloaded or accessed, the content is displayed as part of a web page in the browser or as an attachment in a download dialog box.

Default value:

None

cacheControl

String

No

Explanation:

Cache-Control header in the response. It specifies the cache behavior of the web page when an object is downloaded.

Default value:

None

contentLanguage

String

No

Explanation:

Language or language combination for visitors to customize and use. For details, see the definition of ContentLanguage in the HTTP protocol.

Default value:

None

expires

String

No

Explanation:

The time a cached web page object expires.

Restrictions:

The time must be in the GMT format.

Default value:

None

contentMd5

String

No

Explanation:

Base64-encoded MD5 value of the file data. It is provided for the OBS server to verify data integrity. The OBS server will compare this MD5 value with the MD5 value calculated based on the file data. If the two values are not the same, HTTP status code 400 is returned.

Restrictions:

  • The MD5 value of the file must be Base64 encoded.
  • If the MD5 value is not specified, the OBS server will not verify the MD5 value of the object.

Value range:

Base64-encoded 128-bit MD5 value of the request body calculated according to RFC 1864.

Example: n58IG6hfM7vqI4K0vnWpog==

Default value:

None

storageClass

StorageClassEnum

No

Explanation:

Storage class of an object that can be specified at object creation. If you do not specify this header, the object inherits the storage class of the bucket.

Value range:

See Table 16.

Default value:

None

webSiteRedirectLocation

String

No

Explanation:

If the bucket is configured with website hosting, the request for obtaining the object can be redirected to another object in the bucket or an external URL. This parameter specifies the address the request for the object is redirected to.

The request is redirected to an object anotherPage.html in the same bucket:

WebsiteRedirectLocation:/anotherPage.html

The request is redirected to an external URL http://www.example.com/:

WebsiteRedirectLocation:http://www.example.com/

Restrictions:

  • The value must start with a slash (/), http://, or https:// and cannot exceed 2 KB.
  • OBS only supports redirection for objects in the root directory of a bucket.

Default value:

None

nextPosition

long

No

Explanation:

Start position for the next append upload.

Value range:

0 to the object length, in bytes.

Default value:

None

appendable

boolean

No

Explanation:

Whether the object is appendable.

Value range:

true: The object is appendable.

false: The object is not appendable.

Default value:

None

userMetadata

Map<String, Object>

No

Explanation:

User-defined metadata of the object. To define it, you can add a header starting with x-obs-meta- in the request. In Map, the String key indicates the name of the user-defined metadata that starts with x-obs-meta-, and the Object value indicates the value of the user-defined metadata. To obtain the user-defined metadata of an object, use ObsClient.getObjectMetadata. For details, see Obtaining Object Metadata (SDK for Java).

Restrictions:

  • An object can have multiple pieces of metadata. The size of the metadata cannot exceed 8 KB in total.
  • When you call ObsClient.getObject to download an object, its user-defined metadata will also be downloaded.

Default value:

None

Table 16 StorageClassEnum

Constant

Default Value

Description

STANDARD

STANDARD

Standard storage class

WARM

WARM

Infrequent Access storage class.

COLD

COLD

Archive storage class.

Responses

Table 17 CopyObjectResult

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

responseHeaders

Map<String, Object>

Explanation:

Response header list, composed of tuples. In a tuple, the String key indicates the name of the header, and the Object value indicates the value of the header.

Default value:

None

lastModified

java.util.Date

Explanation:

Last time the target object was modified.

Default value:

None

etag

String

Explanation:

ETag of the target object. Base64-encoded, 128-bit MD5 value of an object. ETag is the unique identifier of the object contents and is used to determine whether the contents of an object are changed. For example, if the ETag value is A when an object is uploaded and is B when the object is downloaded, this indicates the contents of the object are changed. The ETag reflects changes only to the contents of an object, not its metadata. Objects created by the upload and copy operations have unique ETags 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

versionId

String

Explanation:

Version ID of the target object.

Value range:

The value must contain 32 characters.

Default value:

None

copySourceVersionId

String

Explanation:

Version ID of the source object.

Value range:

The value must contain 32 characters.

Default value:

None

storageClass

StorageClassEnum

Explanation:

Storage class of the target object.

Value range:

See Table 16.

Default value:

None

Code Examples

This example sets a version ID to copy object versions of sourceobjectname from bucket sourceexamplebucket to another bucket.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.CopyObjectRequest;
public class CopyObject001 {
    public static void main(String[] args) {
        // 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.
        String ak = System.getenv("ACCESS_KEY_ID");
        String sk = System.getenv("SECRET_ACCESS_KEY_ID");
        // (Optional) If you are using a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding, which may result in information leakage.
        // Obtain an AK/SK pair and a security token using environment variables or import them in other ways.
        // String securityToken = System.getenv("SECURITY_TOKEN");
        // Enter the endpoint corresponding to the bucket. EU-Dublin is used here as an example. Replace it with the one in your actual situation.
        String endPoint = "https://obs.eu-west-101.myhuaweicloud.eu"; 
        // Obtain an endpoint using environment variables or import it in other ways.
        //String endPoint = System.getenv("ENDPOINT");
        
        // Create an ObsClient instance.
        // Use the permanent AK/SK pair to initialize the client.
        ObsClient obsClient = new ObsClient(ak, sk,endPoint);
        // Use the temporary AK/SK pair and security token to initialize the client.
        // ObsClient obsClient = new ObsClient(ak, sk, securityToken, endPoint);

        try {
            // Copy object versions.
            CopyObjectRequest request = new CopyObjectRequest();
            request.setSourceBucketName("sourceexamplebucket");
            request.setSourceObjectKey("sourceobjectname");
            // Set the version ID of the object to be copied.
            request.setVersionId("versionid");
            request.setDestinationBucketName("destexamplebucket");
            request.setDestinationObjectKey("destobjectname");
            obsClient.copyObject(request);
            System.out.println("copyObject successfully");
        } catch (ObsException e) {
            System.out.println("copyObject failed");
            // Request failed. Print the HTTP status code.
            System.out.println("HTTP Code:" + e.getResponseCode());
            // Request failed. Print the server-side error code.
            System.out.println("Error Code:" + e.getErrorCode());
            // Request failed. Print the error details.
            System.out.println("Error Message:" + e.getErrorMessage());
            // Request failed. Print the request ID.
            System.out.println("Request ID:" + e.getErrorRequestId());
            System.out.println("Host ID:" + e.getErrorHostId());
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("copyObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}