Obtaining Bucket Metadata (SDK for Java)
Function
This API returns information about a bucket, including the storage class, region, CORS rules, and redundancy policy.
![](https://support.huaweicloud.com/intl/en-us/sdk-java-devg-obs/public_sys-resources/notice_3.0-en-us.png)
If you have any questions during development, post them on the Issues page of GitHub.
Restrictions
- To obtain bucket metadata, you must be the bucket owner or have the required permission (obs:bucket:HeadBucket in IAM or HeadBucket in a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Creating a Custom Bucket Policy.
- The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.
- For details about values for methods such as BucketMetadataInfoResult.getAllowMethods, see the CORS configurations of the bucket.
Method
obsClient.getBucketMetadata(BucketMetadataInfoRequest request)
Request Parameters
Parameter |
Type |
Mandatory (Yes/No) |
Description |
---|---|---|---|
request |
Yes |
Explanation: Request parameters for obtaining bucket metadata. For details, see Table 2. |
Parameter |
Type |
Mandatory (Yes/No) |
Description |
---|---|---|---|
bucketName |
String |
Yes |
Explanation: Bucket name. Restrictions:
Default value: None |
origin |
String |
No |
Explanation: Origin of the cross-domain request specified by the preflight request. Generally, it is a domain name. Restrictions: You can configure one or more rules and use at most one wildcard character (*) in each rule. If you want to configure multiple rules, separate them using a line breaker. Default value: None |
requestHeaders |
List<String> |
No |
Explanation: HTTP headers in a cross-origin request. Only CORS requests matching the allowed headers are valid. Restrictions: You can enter multiple allowed headers, with one separated from another using a line break. Each header can contain one wildcard character (*) at most. Spaces, ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value: None |
Responses
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 |
location |
String |
Explanation: Region where a bucket is located. Restrictions: If the used endpoint is obs.myhuaweicloud.com, this parameter is not required. If any other endpoint is used, this parameter is required. Value range: To learn about valid regions and endpoints, see Regions and Endpoints. An endpoint is the request address for calling an API. Endpoints vary depending on services and regions. To obtain the regions and endpoints, contact the enterprise administrator. Default value: If obs.myhuaweicloud.com is used as the endpoint and no region is specified, cn-north-1 (the CN North-Beijing1 region) is used by default. |
obsVersion |
String |
Explanation: OBS version of the bucket. Value range:
Default value: None |
storageClass |
Explanation: Bucket storage class that can be specified at bucket creation. Value range: See Table 6. Default value: STANDARD |
|
allowOrigin |
String |
Explanation: If Origin in the request meets the CORS rules of the bucket, AllowedOrigin specified in the CORS rules is returned. Restrictions: You can configure one or more rules and use at most one wildcard character (*) in each rule. If you want to configure multiple rules, separate them using a line breaker. Default value: None |
allowHeaders |
List<String> |
Explanation: If RequestHeader in the request meets the CORS rules of the bucket, AllowedHeader specified in the CORS rules is returned. Restrictions: You can enter multiple allowed headers, with one separated from another using a line break. Each header can contain one wildcard character (*) at most. Spaces, ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value: None |
allowMethods |
List<String> |
Explanation: The allowed HTTP methods for a cross-origin request, indicating the operation types of buckets and objects. Value range: The following HTTP methods are supported:
Default value: None |
exposeHeaders |
List<String> |
Explanation: The CORS-allowed additional headers in the response. These headers provide additional information to clients. By default, your browser can only access headers Content-Length and Content-Type. If your browser needs to access other headers, add them to the list of the allowed additional headers. Restrictions: Spaces, wildcard characters (*), ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value: None |
maxAge |
int |
Explanation: Time your client can cache the response for a cross-origin request Restrictions: Each CORS rule can contain only one maxAge. Value range: An integer greater than 0, in seconds Default value: 100 |
epid |
String |
Explanation: Enterprise project ID that can be specified at bucket creation. If you have enabled EPS, you can obtain the project ID from the EPS console. Restrictions: The value of Epid is a UUID. If the default enterprise project is used, 0 is passed here or Epid is not included. Epid is not required for those who have not enabled the EPS. Example: 9892d768-2d13-450f-aac7-ed0e44c2585f Value range: See How Do I Obtain an Enterprise Project ID? Default value: None |
bucketType |
Explanation: Type of the bucket Value range: See Table 4. Default value: OBJECT, indicating an object bucket |
|
availableZone |
Explanation: Data redundancy policy of the bucket, indicating whether data is stored in a single AZ or multiple AZs. For details, see Table 5. Restrictions: Value 3az means that data is stored in multiple AZs in the same region. If this header is not contained, data is stored in a single AZ. Default value: None |
Constant |
Default Value |
Description |
---|---|---|
OBJECT |
OBJECT |
Object buckets. |
PFS |
POSIX |
Parallel file systems. |
Constant |
Default Value |
Description |
---|---|---|
STANDARD |
STANDARD |
Standard storage class. |
WARM |
WARM |
Infrequent Access storage class. |
COLD |
COLD |
Archive storage class. |
Code Examples
This example obtains the metadata of bucket examplebucket. The origin of the cross-origin request is http://www.exampleorigin.com.
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 62 63 |
import com.obs.services.ObsClient; import com.obs.services.exception.ObsException; import com.obs.services.model.BucketMetadataInfoRequest; import com.obs.services.model.BucketMetadataInfoResult; public class GetBucketMetadata001 { 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 { // Example bucket name String exampleBucket = "examplebucket"; //Example origin String exampleOrigin = "http://www.exampleorigin.com"; BucketMetadataInfoRequest request = new BucketMetadataInfoRequest(exampleBucket); // Specify setOrigin only when cross origin resource sharing (CORS) is used. request.setOrigin(exampleOrigin); // Obtain the bucket metadata. BucketMetadataInfoResult result = obsClient.getBucketMetadata(request); System.out.println("GetBucketMetadata successfully"); System.out.println("GetBucketType:" + result.getBucketType()); System.out.println("GetLocation:" + result.getLocation()); System.out.println("GetBucketStorageClass:" + result.getBucketStorageClass()); System.out.println("GetObsVersion:" + result.getObsVersion()); System.out.println("GetAllowOrigin:" + result.getAllowOrigin()); System.out.println("GetMaxAge:" + result.getMaxAge()); System.out.println("GetAllowHeaders:" + result.getAllowHeaders()); System.out.println("GetAllowMethods:" + result.getAllowMethods()); System.out.println("GetExposeHeaders:" + result.getExposeHeaders()); } catch (ObsException e) { System.out.println("GetBucketMetadata 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("GetBucketMetadata failed"); // Print other error information. e.printStackTrace(); } } } |
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot