Updated on 2024-06-18 GMT+08:00

Configuring an Object ACL (SDK for Java)

Function

OBS allows the control of access permissions for objects. By default, only object creators have the read and write permissions on the object. You can set other access control policies for objects. For example, if an object is configured with the public access policy, all users are allowed to read the object. If an object is encrypted with SSE-KMS, the ACL configured for it is not in effect in the cross-tenant case.

You can set an ACL when uploading an object or call an ACL API to modify or obtain the ACL of an existing object.

If you have any questions during development, post them on the Issues page of GitHub.

Object ACLs, similar to bucket ACLs, support predefined ACLs and direct configurations.

An object ACL can be configured in any of the following ways:

  1. Setting a Pre-defined ACL When Uploading the Object
  2. Calling ObsClient.setObjectAcl to Set a Pre-defined ACL
  3. Calling ObsClient.setObjectAcl to Set an ACL Directly

Restrictions

Method

obsClient.setObjectAcl(SetObjectAclRequest request)

Request Parameters

Table 1 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

request

SetObjectAclRequest

Yes

Explanation:

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

Table 2 SetObjectAclRequest

Parameter

Type

Mandatory (Yes/No)

Description

bucketName

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 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:

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.ap-southeast-1.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

versionId

String

No

Explanation:

Object version ID.

Value range:

The value must contain 32 characters.

Default value:

None

acl

AccessControlList

Yes

Explanation:

An ACL specified for the object. You can use either a pre-defined or a user-defined ACL. For more information about ACLs, see ACLs.

Value range:

  • To use a pre-defined ACL, see Table 3 for the available policies.
  • To use a user-defined ACL, see Table 4 to configure the required parameters.

Default value:

AccessControlList.REST_CANNED_PRIVATE

Table 3 ACL

Constant

Description

AccessControlList.REST_CANNED_PRIVATE

Private read/write.

A bucket or object can only be accessed by its owner.

AccessControlList.REST_CANNED_PUBLIC_READ

Public read.

If this permission is granted on a bucket, anyone can read the object list, multipart uploads, bucket metadata, and object versions in the bucket.

If this permission is granted on an object, anyone can read the content and metadata of the object.

AccessControlList.REST_CANNED_PUBLIC_READ_WRITE

Public read/write.

If this permission is granted on a bucket, anyone can read the object list, multipart uploads, and bucket metadata, and can upload or delete objects, initiate multipart uploads, upload parts, assemble parts, copy parts, and cancel multipart upload tasks.

If this permission is granted on an object, anyone can read the content and metadata of the object.

AccessControlList.REST_CANNED_PUBLIC_READ_DELIVERED

Public read on a bucket as well as objects in the bucket.

If this permission is granted on a bucket, anyone can read the object list, multipart tasks, and bucket metadata, and can also read the content and metadata of the objects in the bucket.

This permission cannot be granted on objects.

AccessControlList.REST_CANNED_PUBLIC_READ_WRITE_DELIVERED

Public read/write on a bucket as well as objects in the bucket.

If this permission is granted on a bucket, anyone can read the object list, multipart uploads, and bucket metadata, and can upload or delete objects, initiate multipart upload tasks, upload parts, assemble parts, copy parts, and abort multipart uploads. They can also read the content and metadata of the objects in the bucket.

This permission cannot be granted on objects.

Table 4 AccessControlList

Parameter

Type

Mandatory (Yes/No)

Description

owner

Owner

Yes

Explanation:

Bucket owner information. For details, see Table 5.

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 6.

Table 5 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 6 GrantAndPermission

Parameter

Type

Mandatory (Yes/No)

Description

grantee

GranteeInterface

Yes

Explanation:

Grantees (users or user groups). For details, see Table 7.

permission

Permission

Yes

Explanation:

Permissions to grant.

Value range:

See Table 10.

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 7 GranteeInterface

Parameter

Type

Mandatory (Yes/No)

Description

CanonicalGrantee

CanonicalGrantee

Yes

Explanation:

Grantee (user) information. For details, see Table 8.

GroupGrantee

GroupGrantee

Yes

Explanation:

Grantee (user group) information.

Value range:

See Table 9.

Default value:

None

Table 8 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 9 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 10 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.

Responses

Table 11 Common response headers

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:

HTTP 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

Code Example: Setting a Pre-defined ACL When Uploading the Object

This example uploads localfile to bucket examplebucket as object objectname, and specifies a pre-defined ACl during the upload.

 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
54
import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.AccessControlList;
import com.obs.services.model.PutObjectRequest;
import java.io.File;
public class PutObject012 {
    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. CN-Hong Kong is used here as an example. Replace it with the one in your actual situation.
        String endPoint = "https://obs.ap-southeast-1.myhuaweicloud.com";
        // 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 {
            // Specify a pre-defined ACL during object upload.
            PutObjectRequest request = new PutObjectRequest();
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            request.setFile(new File("localfile"));
            // Set the object ACL to private.
            request.setAcl(AccessControlList.REST_CANNED_PRIVATE);
            obsClient.putObject(request);
            System.out.println("putObject successfully");
        } catch (ObsException e) {
            System.out.println("putObject 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("putObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Setting a Pre-defined ACL for the Object

This example sets private access to object objectname by specifying a pre-defined ACL.

 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
import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.AccessControlList;
public class SetObjectAcl001 {
    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. CN-Hong Kong is used here as an example. Replace it with the one in your actual situation.
        String endPoint = "https://obs.ap-southeast-1.myhuaweicloud.com";
        // 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 {
            // Set a pre-defined ACL for the object.
            // Set the object ACL to private.
            obsClient.setObjectAcl("examplebucket", "objectname", AccessControlList.REST_CANNED_PRIVATE);
            System.out.println("setObjectAcl successfully");
        } catch (ObsException e) {
            System.out.println("setObjectAcl 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("setObjectAcl failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Setting an ACL for the Object Directly

This example configures an ACL for object objectname in bucket examplebucket.

 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
54
55
56
57
58
59
60
61
import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.AccessControlList;
import com.obs.services.model.CanonicalGrantee;
import com.obs.services.model.GroupGrantee;
import com.obs.services.model.Owner;
import com.obs.services.model.Permission;
public class SetObjectAcl002 {
    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. CN-Hong Kong is used here as an example. Replace it with the one in your actual situation.
        String endPoint = "https://obs.ap-southeast-1.myhuaweicloud.com";
        // 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 {
            AccessControlList acl = new AccessControlList();
            Owner owner = new Owner();
            owner.setId("ownerid");
            // (Mandatory) Owner ID 
            acl.setOwner(owner);
            //Retain the owner's full control permissions. (Note that if this permission is not set, the owner does not have the access permission.)
            acl.grantPermission(new CanonicalGrantee("ownerid"), Permission.PERMISSION_FULL_CONTROL);
            // Grant the full control permission to a specified user.
            acl.grantPermission(new CanonicalGrantee("userid"), Permission.PERMISSION_FULL_CONTROL);
            // Grant the read permission to all users.
            acl.grantPermission(GroupGrantee.ALL_USERS, Permission.PERMISSION_READ);
            obsClient.setObjectAcl("examplebucket", "objectname", acl);
            System.out.println("setObjectAcl successfully");
            System.out.println(acl);
        } catch (ObsException e) {
            System.out.println("setObjectAcl 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("setObjectAcl failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}