Object Storage Service:Perform resumable upload by using OSS SDK for Java

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions, endpoints and open ports.

• In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.

• To use resumable upload, you must have the oss:PutObject permission. For more information, see Attach a custom policy to a RAM user.

Examples

The following sample code provides an example on how to perform resumable upload:

import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();

        // Create an OSSClient instance. 
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();
        
        try {

            ObjectMetadata meta = new ObjectMetadata();
            // Specify the type of content that you want to upload. 
            // meta.setContentType("text/plain");

            // Specify the access control list (ACL) of the object that you want to upload. 
            // meta.setObjectAcl(CannedAccessControlList.Private);

            // Configure multiple parameters by using UploadFileRequest. 
            // Specify the name of the bucket such as examplebucket and the full path of the object such as exampledir/exampleobject.txt. Do not include the bucket name in the full path. 
            UploadFileRequest uploadFileRequest = new UploadFileRequest("examplebucket","exampledir/exampleobject.txt");

            // Configure a single parameter by using UploadFileRequest.            
            // Specify the full path of the local file that you want to upload. Example: D:\\localpath\\examplefile.txt. By default, if you do not specify the full path of the local file, the local file is uploaded from the path of the project to which the sample program belongs. 
            uploadFileRequest.setUploadFile("D:\\localpath\\examplefile.txt");
            // Specify the number of concurrent threads for the upload task. Default value: 1. 
            uploadFileRequest.setTaskNum(5);
            // Specify the part size. Unit: bytes. Valid values: 100 KB to 5 GB. Default value: 100 KB. 
            uploadFileRequest.setPartSize(1 * 1024 * 1024);
            // Specify whether to enable resumable upload. By default, resumable upload is disabled. 
            uploadFileRequest.setEnableCheckpoint(true);
            // Specify the checkpoint file that records the upload progress of each part. This checkpoint file stores information about the upload progress. If a part fails to be uploaded, the task can be continued based on the progress recorded in the checkpoint file. After the local file is uploaded to OSS, the checkpoint file is deleted. 
            // By default, if you do not specify this parameter, the checkpoint file is stored in the same directory as the local file that you want to upload. The directory is named ${uploadFile}.ucp. 
            uploadFileRequest.setCheckpointFile("yourCheckpointFile");
            // Configure object metadata. 
            uploadFileRequest.setObjectMetadata(meta);
            // Configure an upload callback. The parameter type is Callback. 
            //uploadFileRequest.setCallback("yourCallbackEvent");

            // Start resumable upload. 
            ossClient.uploadFile(uploadFileRequest);

        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (Throwable ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
                // Shut down the OSSClient instance. 
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}           

References

For the complete sample code that is used to perform resumable upload, visit GitHub.