LowLevelMultipartCopy.java - AWS Code Sample


LowLevelMultipartCopy.java demonstrates how to perform a multipart upload of an S3 object.

/** * Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * This file is licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. A copy of * the License is located at * * http://aws.amazon.com/apache2.0/ * * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR * CONDITIONS OF ANY KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. */ import com.amazonaws.AmazonServiceException; import com.amazonaws.SdkClientException; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.regions.Regions; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3ClientBuilder; import com.amazonaws.services.s3.model.*; import java.io.IOException; import java.util.ArrayList; import java.util.List; public class LowLevelMultipartCopy { public static void main(String[] args) throws IOException { Regions clientRegion = Regions.DEFAULT_REGION; String sourceBucketName = "*** Source bucket name ***"; String sourceObjectKey = "*** Source object key ***"; String destBucketName = "*** Target bucket name ***"; String destObjectKey = "*** Target object key ***"; try { AmazonS3 s3Client = AmazonS3ClientBuilder.standard() .withCredentials(new ProfileCredentialsProvider()) .withRegion(clientRegion) .build(); // Initiate the multipart upload. InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(destBucketName, destObjectKey); InitiateMultipartUploadResult initResult = s3Client.initiateMultipartUpload(initRequest); // Get the object size to track the end of the copy operation. GetObjectMetadataRequest metadataRequest = new GetObjectMetadataRequest(sourceBucketName, sourceObjectKey); ObjectMetadata metadataResult = s3Client.getObjectMetadata(metadataRequest); long objectSize = metadataResult.getContentLength(); // Copy the object using 5 MB parts. long partSize = 5 * 1024 * 1024; long bytePosition = 0; int partNum = 1; List<CopyPartResult> copyResponses = new ArrayList<CopyPartResult>(); while (bytePosition < objectSize) { // The last part might be smaller than partSize, so check to make sure // that lastByte isn't beyond the end of the object. long lastByte = Math.min(bytePosition + partSize - 1, objectSize - 1); // Copy this part. CopyPartRequest copyRequest = new CopyPartRequest() .withSourceBucketName(sourceBucketName) .withSourceKey(sourceObjectKey) .withDestinationBucketName(destBucketName) .withDestinationKey(destObjectKey) .withUploadId(initResult.getUploadId()) .withFirstByte(bytePosition) .withLastByte(lastByte) .withPartNumber(partNum++); copyResponses.add(s3Client.copyPart(copyRequest)); bytePosition += partSize; } // Complete the upload request to concatenate all uploaded parts and make the copied object available. CompleteMultipartUploadRequest completeRequest = new CompleteMultipartUploadRequest( destBucketName, destObjectKey, initResult.getUploadId(), getETags(copyResponses)); s3Client.completeMultipartUpload(completeRequest); System.out.println("Multipart copy complete."); } catch (AmazonServiceException e) { // The call was transmitted successfully, but Amazon S3 couldn't process // it, so it returned an error response. e.printStackTrace(); } catch (SdkClientException e) { // Amazon S3 couldn't be contacted for a response, or the client // couldn't parse the response from Amazon S3. e.printStackTrace(); } } // This is a helper function to construct a list of ETags. private static List<PartETag> getETags(List<CopyPartResult> responses) { List<PartETag> etags = new ArrayList<PartETag>(); for (CopyPartResult response : responses) { etags.add(new PartETag(response.getPartNumber(), response.getETag())); } return etags; } }

Sample Details

Service: s3

Last tested: 2019-01-28

Author: AWS

Type: full-example