Code Example of a Multipart Upload (SDK for Java)

import com.obs.services.ObsClient;
import com.obs.services.exception.ObsException;
import com.obs.services.model.CompleteMultipartUploadRequest;
import com.obs.services.model.InitiateMultipartUploadRequest;
import com.obs.services.model.InitiateMultipartUploadResult;
import com.obs.services.model.PartEtag;
import com.obs.services.model.UploadPartRequest;
import com.obs.services.model.UploadPartResult;
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class ConcurrentUploadPart001 {
    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 {
            final String bucketName = "examplebucket";
            final String objectKey = "objectname";
            // Initialize the thread pool.
            ExecutorService executorService = Executors.newFixedThreadPool(20);
            final File largeFile = new File("localfile");
            // Initiate a multipart upload.
            InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, objectKey);
            InitiateMultipartUploadResult result = obsClient.initiateMultipartUpload(request);
            final String uploadId = result.getUploadId();
            System.out.println("\t" + uploadId + "\n");
            // Set the part size to 100 MB.
            long partSize = 100 * 1024 * 1024L;
            long fileSize = largeFile.length();
            // Calculate the number of parts to be uploaded.
            long partCount = fileSize % partSize == 0 ? fileSize / partSize : fileSize / partSize + 1;
            final List<PartEtag> partEtags = Collections.synchronizedList(new ArrayList<PartEtag>());
            // Start uploading parts concurrently.
            for (int i = 0; i < partCount; i++) {
                // Set the start position of a part in the file.
                final long offset = i * partSize;
                // Set the part size.
                final long currPartSize = (i + 1 == partCount) ? fileSize - offset : partSize;
                // Set the part number.
                final int partNumber = i + 1;
                executorService.execute(
                        new Runnable() {
                            @Override
                            public void run() {
                                UploadPartRequest uploadPartRequest = new UploadPartRequest();
                                uploadPartRequest.setBucketName(bucketName);
                                uploadPartRequest.setObjectKey(objectKey);
                                uploadPartRequest.setUploadId(uploadId);
                                uploadPartRequest.setFile(largeFile);
                                uploadPartRequest.setPartSize(currPartSize);
                                uploadPartRequest.setOffset(offset);
                                uploadPartRequest.setPartNumber(partNumber);
                                UploadPartResult uploadPartResult;
                                try {
                                    uploadPartResult = obsClient.uploadPart(uploadPartRequest);
                                    System.out.println("Part#" + partNumber + " done\n");
                                    partEtags.add(
                                            new PartEtag(uploadPartResult.getEtag(), uploadPartResult.getPartNumber()));
                                } catch (ObsException e) {
                                    e.printStackTrace();
                                }
                            }
                        });
            }
            // Wait until the upload is complete.
            executorService.shutdown();
            while (!executorService.isTerminated()) {
                try {
                    executorService.awaitTermination(5, TimeUnit.SECONDS);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            // Assemble parts.
            CompleteMultipartUploadRequest completeMultipartUploadRequest =
                    new CompleteMultipartUploadRequest(bucketName, objectKey, uploadId, partEtags);
            obsClient.completeMultipartUpload(completeMultipartUploadRequest);
            System.out.println("completeMultipartUpload successfully");
        } 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();
        }
    }
}