Uploading a Symbolic Link (SDK for Java)

Function

This API uploads a symbolic link.

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

Restrictions

To upload a symbolic link, 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.
The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.

Method

HeaderResponse putSymlink(PutSymlinkRequest request)

Request Parameters

**Table 1** List of request parameters
Parameter	Type	Mandatory (Yes/No)	Description
request	PutSymlinkRequest	Yes	Explanation: Request parameters for setting object properties. For details, see Table 2.

**Table 2** PutSymlinkRequest
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 a period (.) and a hyphen (-) adjacent to each other, for example, my-.bucket or my.-bucket. If you repeatedly create buckets with 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: Symbolic link name. An object is uniquely identified by an object name in a bucket. An object name is a complete path of the object 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
symlinkTarget	String	Yes	Explanation: Name of the target object that the symbolic link points to. Value range: The value must contain 1 to 1,024 characters. Default value: None
acl	AccessControlList	No	Explanation: ACL that can be pre-defined when an object is created. Refer to Table 3 to choose the option you need. For details about ACLs, see ACLs. Value range: To use a pre-defined ACL, see Table 11 for the available options. To use a user-defined ACL, see Table 3 to configure the required parameters. Default value: None
objectMetadata	ObjectMetadata	No	Explanation: Object metadata. For details, see Table 9. Default value: None

**Table 3** AccessControlList
Parameter	Type	Mandatory (Yes/No)	Type
owner	Owner	No	Explanation: Bucket owner information. For details, see Table 4.
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 5.

**Table 4** 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 5** GrantAndPermission
Parameter	Type	Mandatory (Yes/No)	Description
grantee	CanonicalGrantee or GroupGrantee	Yes	Explanation: Grantees (users or user groups). Value range: Grantee (user) information. For details, see Table 7. Grantee (user group) information. For details, see Table 8.
permission	Permission	Yes	Explanation: Permissions to grant. Value range: See Table 6. 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 6** 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, READ_ACP, and WRITE_ACP permissions for the object.

**Table 7** 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	Explanation: 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 8** 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 9** 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. 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 name for the requested object. When the object with the default 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: The language or languages intended for the audience. For details, see the definition of ContentLanguage in HTTP. Default value: None
expires	String	No	Explanation: The time a cached web page object expires. Restrictions: The time must be in the GMT format, for example, Wed, 27 Jun 2018 13:46:58 GMT. Default value: None
contentMd5	String	No	Explanation: Base64-encoded MD5 value of the object 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 object data. If the two values are not the same, HTTP status code 400 is returned. Restrictions: The MD5 value of the object 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: Object storage class. When creating an object, you can use this header to specify the storage class for the object. If you do not specify this header, the object inherits the storage class of the bucket. Value range: See Table 10. 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. To another object in the same bucket: WebsiteRedirectLocation:/anotherPage.html To an external URL: 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 total metadata size cannot exceed 8 KB. When you call ObsClient.getObject to download an object, its user-defined metadata will also be downloaded. Default value: None

**Table 10** StorageClassEnum
Constant	Default Value	Description
STANDARD	STANDARD	Standard storage class.
WARM	WARM	Infrequent Access storage class.
COLD	COLD	Archive storage class.

**Table 11** Pre-defined 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 abort 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.
AccessControlList.REST_CANNED_BUCKET_OWNER_FULL_CONTROL	If this permission is granted on an object, only the bucket and object owners have the full control over the object. By default, if you upload an object to a bucket owned by another user, the bucket owner does not have the permissions on your object. After you grant this permission to the bucket owner, the bucket owner can have full control over your object. For example, if user A uploads object x to user B's bucket, user B does not have control over object x. If user A sets bucket-owner-full-control for object x, user B then has control over object x.

Responses

**Table 12** Response headers
Method	Return Value Type	Description
putSymlink(PutSymlinkRequest request)	HeaderResponse	Results returned for the request to upload a symbolic link.

**Table 13** 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

This example uploads the symbolic link symlinkobject that points to the target object targetobject to bucket examplebucket.

     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 currently in use.
        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 a permanent AK/SK pair to initialize the client.
        ObsClient obsClient = new ObsClient(ak, sk, endPoint);
        // Use a temporary AK/SK pair and security token to initialize the client.
        // ObsClient obsClient = new ObsClient(ak, sk, securityToken, endPoint);

        try {
            // Upload the symbolic link without setting the ACL and metadata.
            PutSymlinkRequest request = new PutSymlinkRequest("examplebucket", "symlinkobject", "targetobject", null, null);
            obsClient.putSymlink(request);
            System.out.println("putSymlink successfully");
        } catch (ObsException e) {
            System.out.println("putSymlink 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("putSymlink failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}
 
 
  

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Uploading a Symbolic Link (SDK for Java)

Function

Restrictions

Method

Request Parameters

Responses

Code Example

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