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

Accessing OBS Using a Signed URL (SDK for Java)

Function

ObsClient allows you to create a URL with Query parameters that carry authentication information by specifying the AK and SK, HTTP method, and request parameters. You can provide this URL to other users for them to make a temporary access. When generating a URL, you need to specify the validity period of the URL to restrict the access duration of visitors.

If you want to grant other users the permission to perform operations on buckets or objects (for example, upload or download objects), you need to generate a URL for the corresponding request (for example, a URL with the PUT request for uploading an object) and provide the URL to other users.

If a CORS or signature mismatch error occurs, refer to the following steps to troubleshoot the issue:
  1. If CORS is not configured, you need to configure CORS rules on OBS Console. For details, see Configuring CORS.
  2. If the signatures do not match, check whether signature parameters are correct. For details, see Authentication of Signature in a URL. For example, during an object upload, the backend uses Content-Type to calculate the signature and generate an authorized URL, but if Content-Type is not set or is set to an incorrect value when the frontend uses the authorized URL, a CORS error occurs. To avoid this issue, ensure that Content-Type fields are the same at the frontend and backend.
  3. A CDN acceleration domain name cannot be used to create a signed URL.

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

The following table lists operations that can be performed through a signed URL.

Table 1 HttpMethodEnum & SpecialParamEnum

Operation

HTTP Request Method (Value in OBS SDK for Java)

Special Operator (Value in OBS SDK for Java)

Bucket Name Required (Yes/No)

Object Name Required (Yes/No)

Create Bucket

HttpMethodEnum.PUT

N/A

Yes

No

List Buckets

HttpMethodEnum.GET

N/A

No

No

Delete Bucket

HttpMethodEnum.DELETE

N/A

Yes

No

List Objects

HttpMethodEnum.GET

N/A

Yes

No

List Object Versions

HttpMethodEnum.GET

SpecialParamEnum.VERSIONS

Yes

No

List Multipart Uploads

HttpMethodEnum.GET

SpecialParamEnum.UPLOADS

Yes

No

Get Bucket Metadata

HttpMethodEnum.HEAD

N/A

Yes

No

Get Bucket Location

HttpMethodEnum.GET

SpecialParamEnum.LOCATION

Yes

No

Get Bucket Storageinfo

HttpMethodEnum.GET

SpecialParamEnum.STORAGEINFO

Yes

No

Set Bucket Quota

HttpMethodEnum.PUT

SpecialParamEnum.QUOTA

Yes

No

Get Bucket Quota

HttpMethodEnum.GET

SpecialParamEnum.QUOTA

Yes

No

Set Bucket Storage Policy

HttpMethodEnum.PUT

SpecialParamEnum.STORAGEPOLICY

Yes

No

Get Bucket Storage Policy

HttpMethodEnum.GET

SpecialParamEnum.STORAGEPOLICY

Yes

No

Set Bucket ACL

HttpMethodEnum.PUT

SpecialParamEnum.ACL

Yes

No

Get Bucket ACL

HttpMethodEnum.GET

SpecialParamEnum.ACL

Yes

No

Set Bucket Logging

HttpMethodEnum.PUT

SpecialParamEnum.LOGGING

Yes

No

Get Bucket Logging

HttpMethodEnum.GET

SpecialParamEnum.LOGGING

Yes

No

Set Bucket Policy

HttpMethodEnum.PUT

SpecialParamEnum.POLICY

Yes

No

Get Bucket Policy

HttpMethodEnum.GET

SpecialParamEnum.POLICY

Yes

No

Delete Bucket Policy

HttpMethodEnum.DELETE

SpecialParamEnum.POLICY

Yes

No

Set Lifecycle Rule

HttpMethodEnum.PUT

SpecialParamEnum.LIFECYCLE

Yes

No

Get Lifecycle Rule

HttpMethodEnum.GET

SpecialParamEnum.LIFECYCLE

Yes

No

Delete Lifecycle Rule

HttpMethodEnum.DELETE

SpecialParamEnum.LIFECYCLE

Yes

No

Set Website Hosting

HttpMethodEnum.PUT

SpecialParamEnum.WEBSITE

Yes

No

Get Website Hosting

HttpMethodEnum.GET

SpecialParamEnum.WEBSITE

Yes

No

Delete Website Hosting

HttpMethodEnum.DELETE

SpecialParamEnum.WEBSITE

Yes

No

Set Bucket Versioning

HttpMethodEnum.PUT

SpecialParamEnum.VERSIONING

Yes

No

Get Bucket Versioning

HttpMethodEnum.GET

SpecialParamEnum.VERSIONING

Yes

No

Set CORS Rule

HttpMethodEnum.PUT

SpecialParamEnum.CORS

Yes

No

Get CORS Rule

HttpMethodEnum.GET

SpecialParamEnum.CORS

Yes

No

Delete CORS Rule

HttpMethodEnum.DELETE

SpecialParamEnum.CORS

Yes

No

Set Bucket Tagging

HttpMethodEnum.PUT

SpecialParamEnum.TAGGING

Yes

No

Get Bucket Tagging

HttpMethodEnum.GET

SpecialParamEnum.TAGGING

Yes

No

Delete Bucket Tagging

HttpMethodEnum.DELETE

SpecialParamEnum.TAGGING

Yes

No

Upload Object

HttpMethodEnum.PUT

N/A

Yes

Yes

Append Object

HttpMethodEnum.POST

SpecialParamEnum.APPEND

Yes

Yes

Get Object

HttpMethodEnum.GET

N/A

Yes

Yes

Copy Object

HttpMethodEnum.PUT

N/A

Yes

Yes

Delete Object

HttpMethodEnum.DELETE

N/A

Yes

Yes

Delete Objects

HttpMethodEnum.POST

SpecialParamEnum.DELETE

Yes

Yes

Get Object Metadata

HttpMethodEnum.HEAD

N/A

Yes

Yes

Set Object ACL

HttpMethodEnum.PUT

SpecialParamEnum.ACL

Yes

Yes

Get Object ACL

HttpMethodEnum.GET

SpecialParamEnum.ACL

Yes

Yes

Initiate Multipart Upload

HttpMethodEnum.POST

SpecialParamEnum.UPLOADS

Yes

Yes

Upload Part

HttpMethodEnum.PUT

N/A

Yes

Yes

Copy Part

HttpMethodEnum.PUT

N/A

Yes

Yes

List Parts

HttpMethodEnum.GET

N/A

Yes

Yes

Assemble Parts

HttpMethodEnum.POST

N/A

Yes

Yes

Delete Multipart Upload

HttpMethodEnum.DELETE

N/A

Yes

Yes

Restore Archive Object

HttpMethodEnum.POST

SpecialParamEnum.RESTORE

Yes

Yes

To access OBS using a signed URL generated by the OBS SDK for Java, perform the following steps:

  1. Call ObsClient.createTemporarySignature to generate a signed URL.
  2. Use an HTTP library to make an HTTP/HTTPS request to OBS.

Restrictions

  • The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.

Method

obsClient.createTemporarySignature(TemporarySignatureRequest request)

Request Parameters

Table 2 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

request

TemporarySignatureRequest

Yes

Explanation:

Request parameters for creating a signed URL. For details, see Table 3.

Table 3 TemporarySignatureRequest

Parameter

Type

Mandatory (Yes/No)

Description

bucketName

String

No

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

No

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

specialParam

SpecialParamEnum

No

Explanation:

Special parameters that may be used in the request, indicating the sub-operations.

Value range:

See Table 1.

Default value:

None

method

HttpMethodEnum

Yes

Explanation:

HTTP method type.

Value range:

See Table 1.

Default value:

None

headers

Map<String, String>

No

Explanation:

Headers in the request. In Map, the String key and value indicate the name and value of the request header respectively.

Default value:

None

queryParams

Map<String, Object>

No

Explanation:

Query parameters in the request. In Map, the String key indicates the name of the query parameter, and the Object value indicates the value of the query parameter.

Default value:

None

expires

long

Yes

Explanation:

Expiration time of the signed URL.

Value range:

An integer greater than or equal to 0, in seconds.

Default value:

300

requestDate

Date

Yes

Explanation:

Time when the request is initiated.

Default value:

None

Responses

Table 4 TemporarySignatureResponse

Parameter

Type

Description

signedUrl

String

Explanation:

The signed URL that carries the authentication information.

Default value:

None

actualSignedRequestHeaders

Map<String, String>

Explanation:

Actual headers in the request initiated using the signed URL. In Map, the String key and value indicate the name and value of the request header respectively.

Default value:

None

Code Example: Creating a Bucket

This example uses HttpMethodEnum.PUT to create bucket examplebucket based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import java.util.Map;
public class CreateBucket001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.PUT, expireSeconds);
            request.setBucketName("examplebucket");
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Creating bucket using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a PUT request to create a bucket.
            String location = "your bucket location";
            Request httpRequest =
                    builder.url(response.getSignedUrl())
                            .put(
                                    RequestBody.create(
                                            null,
                                            "<CreateBucketConfiguration><Location>"
                                                    + location
                                                    + "</Location></CreateBucketConfiguration>".getBytes()))
                            .build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("\tStatus:" + res.code());
            if (res.body() != null) {
                System.out.println("\tContent:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("CreateBucket successfully");
        } catch (ObsException e) {
            System.out.println("CreateBucket 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("CreateBucket failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Uploading an Object

This example uses HttpMethodEnum.PUT to upload object objectname to bucket examplebucket based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import java.util.HashMap;
import java.util.Map;
public class PutObject001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            Map<String, String> headers = new HashMap<>();
            String contentType = "text/plain";
            headers.put("Content-Type", contentType);
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.PUT, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            request.setHeaders(headers);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Creating object using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a PUT request to upload an object.
            Request httpRequest =
                    builder.url(response.getSignedUrl())
                            .put(RequestBody.create(MediaType.parse(contentType), "Hello OBS".getBytes("UTF-8")))
                            .build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            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: Downloading an Object

This example uses HttpMethodEnum.GET to download object objectname from bucket examplebucket based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import java.io.InputStream;
import java.util.Map;
public class GetObject001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Getting object using temporary signature url:");
            System.out.println("SignedUrl:" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a GET request to download an object.
            Request httpRequest = builder.url(response.getSignedUrl()).get().build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            InputStream objectContent = null;
            if (res.body() != null) {
                objectContent = res.body().byteStream();
                System.out.println("Content:" + res.body().string() + "\n");
            }
            if(objectContent != null) {
                // objectContent is the file stream to download.
                // You can read the objectContent stream to download the file. If the stream is not read for a long time, it will be disconnected from the server.
            }
            res.close();
            System.out.println("getObject successfully");
        } catch (ObsException e) {
            System.out.println("getObject 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("getObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Listing Objects

This example uses HttpMethodEnum.GET to list object in bucket examplebucket based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import java.util.Map;
public class ListObject001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
            request.setBucketName("examplebucket");
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Getting object list using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a GET request to obtain the object list.
            Request httpRequest = builder.url(response.getSignedUrl()).get().build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("ListObject successfully");
        } catch (ObsException e) {
            System.out.println("ListObject 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("ListObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Deleting an Object

This example uses HttpMethodEnum.DELETE to delete object objectname from bucket examplebucket based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import java.util.Map;
public class DeleteObject001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.DELETE, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Deleting object using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a DELETE request to delete an object.
            Request httpRequest = builder.url(response.getSignedUrl()).delete().build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("\tStatus:" + res.code());
            if (res.body() != null) {
                System.out.println("\tContent:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("deleteObjects successfully");
        } catch (ObsException e) {
            System.out.println("deleteObjects 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("deleteObjects failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Initiating a Multipart Upload

This example uses HttpMethodEnum.POST to initiate a multipart upload based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.SpecialParamEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import java.util.Map;
public class InitiateMultiPartUpload001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.POST, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            request.setSpecialParam(SpecialParamEnum.UPLOADS);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("initiate multipart upload using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a POST request to initiate the multipart upload.
            Request httpRequest = builder.url(response.getSignedUrl()).post(RequestBody.create(null, "")).build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("InitiateMultiPartUpload successfully");
        } catch (ObsException e) {
            System.out.println("InitiateMultiPartUpload 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("InitiateMultiPartUpload failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Uploading a Part

This example uses HttpMethodEnum.PUT to upload a part based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import java.util.HashMap;
import java.util.Map;
public class UploadPart001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.PUT, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            Map<String, Object> queryParams = new HashMap<String, Object>();
            // Set the partNumber parameter, for example, queryParams.put("partNumber", "1").
            queryParams.put("partNumber", "partNumber");
            queryParams.put("uploadId", "your uploadId");
            request.setQueryParams(queryParams);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("upload part using temporary signature url:");
            System.out.println("SignedUrl:" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a PUT request to upload a part.
            Request httpRequest =
                    builder.url(response.getSignedUrl())
                            .put(RequestBody.create(null, new byte[6 * 1024 * 1024]))
                            .build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("UploadPart successfully");
        } catch (ObsException e) {
            System.out.println("UploadPart 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("UploadPart failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Listing Uploaded Parts

This example uses HttpMethodEnum.PUT to list uploaded parts based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import java.util.HashMap;
import java.util.Map;
public class ListUploadedParts001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            Map<String, Object> queryParams = new HashMap<String, Object>();
            queryParams.put("uploadId", "your uploadId");
            request.setQueryParams(queryParams);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("list parts using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a GET request to list uploaded parts.
            Request httpRequest = builder.url(response.getSignedUrl()).get().build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("ListParts successfully");
        } catch (ObsException e) {
            System.out.println("ListParts 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("ListParts failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Assembling Parts

This example uses HttpMethodEnum.POST to assemble parts based on a signed URL. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import java.util.HashMap;
import java.util.Map;
public class CompleteMultiPartUpload001 {
    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 the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.POST, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            Map<String, String> headers = new HashMap<>();
            String contentType = "application/xml";
            headers.put("Content-Type", contentType);
            request.setHeaders(headers);
            Map<String, Object> queryParams = new HashMap<>();
            queryParams.put("uploadId", "your uploadId");
            request.setQueryParams(queryParams);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("complete multipart upload using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // The following content is used as an example. You need to replace it with the responses of the request for listing uploaded parts.
            String content = "<CompleteMultipartUpload>";
            content += "<Part>";
            content += "<PartNumber>1</PartNumber>";
            content += "<ETag>da6a0d097e307ac52ed9b4ad551801fc</ETag>";
            content += "</Part>";
            content += "<Part>";
            content += "<PartNumber>2</PartNumber>";
            content += "<ETag>da6a0d097e307ac52ed9b4ad551801fc</ETag>";
            content += "</Part>";
            content += "</CompleteMultipartUpload>";
            // Make a POST request to assemble the uploaded parts.
            Request httpRequest =
                    builder.url(response.getSignedUrl())
                            .post(RequestBody.create(MediaType.parse(contentType), content.getBytes("UTF-8")))
                            .build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("\tStatus:" + res.code());
            if (res.body() != null) {
                System.out.println("\tContent:" + res.body().string() + "\n");
            }
            res.close();
        } catch (ObsException e) {
            System.out.println("CompleteMultiPartUpload 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("CompleteMultiPartUpload failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}

Code Example: Processing and Downloading an Image

This example uses HttpMethodEnum.GET to obtain a signed URL for downloading a processed image. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import java.util.HashMap;
import java.util.Map;
public class GetObject002 {
    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 {
            // Obtain a signed URL for downloading a processed image. 
            // Set the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            // Set the parameters for image processing.
            Map<String, Object> queryParams = new HashMap<String, Object>();
            queryParams.put("x-image-process", "image/resize,m_fixed,w_100,h_100/rotate,100");
            request.setQueryParams(queryParams);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            // Obtain the download link for image processing.
            System.out.println("Getting object using temporary signature url:");
            System.out.println("SignedUrl:" + response.getSignedUrl());
        } catch (ObsException e) {
            System.out.println("getObject 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("getObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}
  • The object name and bucket name must be Base64-encoded and have invalid URL characters replaced. The format is encodedObject = url_safe_base64_encode(name). For example, object panda.png is encoded to cGFuZGEucG5n. After Base64 encoding, if the name contains plus signs (+) or slashes (/), replace them, respectively, with hyphens (-) and underscores (_).
  • If there is a signature match error, check whether the AK and SK pair is correct and whether the accessed URL is the same as the signed URL generated by the code.
  • Currently, the range header is not supported by image persistency.

Code Example: Downloading an Object Encrypted Using SSE-C

This example uses HttpMethodEnum.GET to download an object encrypted using SSE-C. The validity period of the URL is 3,600 seconds.

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import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.HttpMethodEnum;
import com.obs.services.model.TemporarySignatureRequest;
import com.obs.services.model.TemporarySignatureResponse;
import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import java.util.HashMap;
import java.util.Map;
public class GetObject003 {
    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 {
            // Download an object encrypted using SSE-C.
            // Set the validity period of the URL to 3600 seconds.
            long expireSeconds = 3600L;
            TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
            request.setBucketName("examplebucket");
            request.setObjectKey("objectname");
            // Set the encryption method to SSE-C.
            Map<String, String> headers = new HashMap<>();
            headers.put("x-obs-server-side-encryption-customer-algorithm", "AES256");
            // Set the key used for encryption, which is a Base64-encoded 256-bit value.
            headers.put(
                    "x-obs-server-side-encryption-customer-key",
                    "your base64 sse-c key generated by AES-256 algorithm");
            // Set the MD5 value of the key used for encryption, which is a Base64-encoded, 128-bit MD5 value.
            headers.put("x-obs-server-side-encryption-customer-key-MD5", "the md5 value of your sse-c key");
            request.setHeaders(headers);
            TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
            System.out.println("Getting object using temporary signature url:");
            System.out.println("\t" + response.getSignedUrl());
            Request.Builder builder = new Request.Builder();
            for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
                builder.header(entry.getKey(), entry.getValue());
            }
            // Make a GET request to download an object.
            Request httpRequest = builder.url(response.getSignedUrl()).get().build();
            OkHttpClient httpClient =
                    new OkHttpClient.Builder()
                            .followRedirects(false)
                            .retryOnConnectionFailure(false)
                            .cache(null)
                            .build();
            Call c = httpClient.newCall(httpRequest);
            Response res = c.execute();
            System.out.println("Status:" + res.code());
            if (res.body() != null) {
                System.out.println("Content:" + res.body().string() + "\n");
            }
            res.close();
            System.out.println("getObject successfully");
        } catch (ObsException e) {
            System.out.println("getObject 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("getObject failed");
            // Print other error information.
            e.printStackTrace();
        }
    }
}
  • HttpMethodEnum is an enumeration function defined in OBS SDK for Java, whose value indicates the request method types.