# Java용 SDK를 사용하여 멀티파트 업로드 수행 및 관리
<a name="S3OutpostsMPU"></a>

Amazon S3 on Outposts를 사용하면 AWS Outposts 리소스에서 S3 버킷을 생성하고 로컬 데이터 액세스, 로컬 데이터 처리 및 데이터 레지던시가 필요한 애플리케이션을 위해 온프레미스에서 객체를 저장하고 검색할 수 있습니다. AWS Management Console, AWS Command Line Interface(AWS CLI), AWS SDK 또는 REST API를 통해 S3 on Outposts를 사용할 수 있습니다. 자세한 내용은 [Amazon S3 on Outposts란 무엇인가요?](S3onOutposts.md) 섹션을 참조하세요. 

다음 예제에서는 AWS SDK for Java와 함께 S3 on Outposts를 사용하여 멀티파트 업로드를 수행하고 관리하는 방법을 보여줍니다.

**Topics**
+ [S3 on Outposts 버킷에 있는 객체의 멀티파트 업로드 수행](#S3OutpostsInitiateMultipartUploadJava)
+ [멀티파트 업로드를 사용하여 S3 on Outposts 버킷에 있는 대형 객체 복사](#S3OutpostsCopyPartJava)
+ [S3 on Outposts 버킷에 있는 객체의 부분 나열](#S3OutpostsListPartsJava)
+ [S3 on Outposts 버킷에서 진행 중인 멀티파트 업로드 목록 검색](#S3OutpostsListMultipartUploadsJava)

## S3 on Outposts 버킷에 있는 객체의 멀티파트 업로드 수행
<a name="S3OutpostsInitiateMultipartUploadJava"></a>

다음 S3 on Outposts 예제에서는 Java용 SDK를 사용하여 버킷에 객체의 멀티파트 업로드를 시작, 업로드 및 완료합니다. 이 예제를 사용하려면 각 `{{user input placeholder}}`를 사용자의 정보로 대체합니다. 자세한 내용은 **Amazon Simple Storage Service 사용 설명서의 [멀티파트 업로드를 사용한 객체 업로드](https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpu-upload-object.html)를 참조하세요.

```
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.*;

import java.util.ArrayList;
import java.util.List;

public class MultipartUploadCopy {
    public static void main(String[] args) {
        String accessPointArn = "{{*** Source access point ARN ***}}";
        String sourceObjectKey = "{{*** Source object key ***}}";
        String destObjectKey = "{{*** Target object key ***}}";

        try {
            // This code expects that you have AWS credentials set up per:
            // https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/setup-credentials.html
            AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                    .enableUseArnRegion()
                    .build();

            // Initiate the multipart upload.
            InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(accessPointArn, destObjectKey);
            InitiateMultipartUploadResult initResult = s3Client.initiateMultipartUpload(initRequest);

            // Get the object size to track the end of the copy operation.
            GetObjectMetadataRequest metadataRequest = new GetObjectMetadataRequest(accessPointArn, 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(accessPointArn)
                        .withSourceKey(sourceObjectKey)
                        .withDestinationBucketName(accessPointArn)
                        .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(
                    accessPointArn,
                    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;
    }
```

## 멀티파트 업로드를 사용하여 S3 on Outposts 버킷에 있는 대형 객체 복사
<a name="S3OutpostsCopyPartJava"></a>

다음 S3 on Outposts 예제에서는 Java용 SDK를 사용하여 버킷에 객체를 복사합니다. 이 예제를 사용하려면 각 `{{user input placeholder}}`를 사용자의 정보로 대체합니다.

```
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.*;

import java.util.ArrayList;
import java.util.List;

public class MultipartUploadCopy {
    public static void main(String[] args) {
        String accessPointArn = "{{*** Source access point ARN ***}}";
        String sourceObjectKey = "{{*** Source object key ***}}";
        String destObjectKey = "{{*** Target object key ***}}";

        try {
            // This code expects that you have AWS credentials set up per:
            // https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/setup-credentials.html
            AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                    .enableUseArnRegion()
                    .build();

            // Initiate the multipart upload.
            InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(accessPointArn, destObjectKey);
            InitiateMultipartUploadResult initResult = s3Client.initiateMultipartUpload(initRequest);

            // Get the object size to track the end of the copy operation.
            GetObjectMetadataRequest metadataRequest = new GetObjectMetadataRequest(accessPointArn, 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(accessPointArn)
                        .withSourceKey(sourceObjectKey)
                        .withDestinationBucketName(accessPointArn)
                        .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(
                    accessPointArn,
                    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;
    }
}
```

## S3 on Outposts 버킷에 있는 객체의 부분 나열
<a name="S3OutpostsListPartsJava"></a>

다음 S3 on Outposts 예제에서는 Java용 SDK를 사용하여 버킷의 객체 파트를 나열합니다. 이 예제를 사용하려면 각 `{{user input placeholder}}`를 사용자의 정보로 대체합니다.

```
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.*;

import java.util.List;

public class ListParts {
    public static void main(String[] args) {
        String accessPointArn = "{{*** access point ARN ***}}";
        String keyName = "{{*** Key name ***}}";
        String uploadId = "{{*** Upload ID ***}}";

        try {
            // This code expects that you have AWS credentials set up per:
            // https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/setup-credentials.html
            AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                    .enableUseArnRegion()
                    .build();

            ListPartsRequest listPartsRequest = new ListPartsRequest(accessPointArn, keyName, uploadId);
            PartListing partListing = s3Client.listParts(listPartsRequest);
            List<PartSummary> partSummaries = partListing.getParts();

            System.out.println(partSummaries.size() + " multipart upload parts");
            for (PartSummary p : partSummaries) {
                System.out.println("Upload part: Part number = \"" + p.getPartNumber() + "\", ETag = " + p.getETag());
            }

        } 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();
        }
    }
}
```

## S3 on Outposts 버킷에서 진행 중인 멀티파트 업로드 목록 검색
<a name="S3OutpostsListMultipartUploadsJava"></a>

다음 S3 on Outposts 예제에서는 Outposts 버킷에서 Java용 SDK를 사용하여 진행 중인 멀티파트 업로드 목록을 검색하는 방법을 보여줍니다. 이 예제를 사용하려면 각 `{{user input placeholder}}`를 사용자의 정보로 대체합니다.

```
import com.amazonaws.AmazonServiceException;
import com.amazonaws.SdkClientException;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.ListMultipartUploadsRequest;
import com.amazonaws.services.s3.model.MultipartUpload;
import com.amazonaws.services.s3.model.MultipartUploadListing;

import java.util.List;

public class ListMultipartUploads {
    public static void main(String[] args) {
                String accessPointArn = "{{*** access point ARN ***}}";

        try {
            // This code expects that you have AWS credentials set up per:
            // https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/setup-credentials.html
            AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                    .enableUseArnRegion()
                    .build();

            // Retrieve a list of all in-progress multipart uploads.
            ListMultipartUploadsRequest allMultipartUploadsRequest = new ListMultipartUploadsRequest(accessPointArn);
            MultipartUploadListing multipartUploadListing = s3Client.listMultipartUploads(allMultipartUploadsRequest);
            List<MultipartUpload> uploads = multipartUploadListing.getMultipartUploads();

            // Display information about all in-progress multipart uploads.
            System.out.println(uploads.size() + " multipart upload(s) in progress.");
            for (MultipartUpload u : uploads) {
                System.out.println("Upload in progress: Key = \"" + u.getKey() + "\", id = " + u.getUploadId());
            }
        } 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();
        }
    }
}
```