使用分段上傳來複製物件

下列 C# 範例示範如何使用 適用於 .NET 的 SDK ，將大於 5 GB 的 Amazon S3 物件從一個來源位置複製到另一個來源位置，例如從一個儲存貯體複製到另一個儲存貯體。若要複製小於 5 GB 的物件，請使用「使用 AWS SDKs」中，所描述的單一操作複製程序。如需 Amazon S3 分段上傳的詳細資訊，請參閱 在 Amazon S3 中使用分段上傳來上傳和複製物件。

此範例示範如何使用 適用於 .NET 的 SDK 分段上傳 API，將大於 5 GB 的 Amazon S3 物件從一個 S3 儲存貯體複製到另一個儲存貯體。

using Amazon;
using Amazon.S3;
using Amazon.S3.Model;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace Amazon.DocSamples.S3
{
    class CopyObjectUsingMPUapiTest
    {
        private const string sourceBucket = "*** provide the name of the bucket with source object ***";
        private const string targetBucket = "*** provide the name of the bucket to copy the object to ***";
        private const string sourceObjectKey = "*** provide the name of object to copy ***";
        private const string targetObjectKey = "*** provide the name of the object copy ***";
        // Specify your bucket region (an example region is shown).
        private static readonly RegionEndpoint bucketRegion = RegionEndpoint.USWest2; 
        private static IAmazonS3 s3Client;

        public static void Main()
        {
            s3Client = new AmazonS3Client(bucketRegion);
            Console.WriteLine("Copying an object");
            MPUCopyObjectAsync().Wait();
        }
        private static async Task MPUCopyObjectAsync()
        {
            // Create a list to store the upload part responses.
            List<UploadPartResponse> uploadResponses = new List<UploadPartResponse>();
            List<CopyPartResponse> copyResponses = new List<CopyPartResponse>();

            // Setup information required to initiate the multipart upload.
            InitiateMultipartUploadRequest initiateRequest =
                new InitiateMultipartUploadRequest
                {
                    BucketName = targetBucket,
                    Key = targetObjectKey
                };

            // Initiate the upload.
            InitiateMultipartUploadResponse initResponse =
                await s3Client.InitiateMultipartUploadAsync(initiateRequest);

            // Save the upload ID.
            String uploadId = initResponse.UploadId;

            try
            {
                // Get the size of the object.
                GetObjectMetadataRequest metadataRequest = new GetObjectMetadataRequest
                {
                    BucketName = sourceBucket,
                    Key = sourceObjectKey
                };

                GetObjectMetadataResponse metadataResponse =
                    await s3Client.GetObjectMetadataAsync(metadataRequest);
                long objectSize = metadataResponse.ContentLength; // Length in bytes.

                // Copy the parts.
                long partSize = 5 * (long)Math.Pow(2, 20); // Part size is 5 MB.

                long bytePosition = 0;
                for (int i = 1; bytePosition < objectSize; i++)
                {
                    CopyPartRequest copyRequest = new CopyPartRequest
                    {
                        DestinationBucket = targetBucket,
                        DestinationKey = targetObjectKey,
                        SourceBucket = sourceBucket,
                        SourceKey = sourceObjectKey,
                        UploadId = uploadId,
                        FirstByte = bytePosition,
                        LastByte = bytePosition + partSize - 1 >= objectSize ? objectSize - 1 : bytePosition + partSize - 1,
                        PartNumber = i
                    };

                    copyResponses.Add(await s3Client.CopyPartAsync(copyRequest));

                    bytePosition += partSize;
                }

                // Set up to complete the copy.
                CompleteMultipartUploadRequest completeRequest =
                new CompleteMultipartUploadRequest
                {
                    BucketName = targetBucket,
                    Key = targetObjectKey,
                    UploadId = initResponse.UploadId
                };
                completeRequest.AddPartETags(copyResponses);

                // Complete the copy.
                CompleteMultipartUploadResponse completeUploadResponse = 
                    await s3Client.CompleteMultipartUploadAsync(completeRequest);
            }
            catch (AmazonS3Exception e)
            {
                Console.WriteLine("Error encountered on server. Message:'{0}' when writing an object", e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine("Unknown encountered on server. Message:'{0}' when writing an object", e.Message);
            }
        }
    }
}