從 Amason S3 on Outposts 儲存貯體取得物件 - Amazon Simple Storage Service

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

從 Amason S3 on Outposts 儲存貯體取得物件

物件是存放在 Amazon S3 on Outposts 中的基本實體。每個物件都包含在儲存貯體中。您必須使用存取點來存取 Outpost 儲存貯體中的任何物件。針對物件操作指定儲存貯體時，您可以使用存取點 Amazon Resource Name (ARN) 或存取點別名。如需存取點別名的詳細資訊，請參閱 針對您的 S3 on Outposts 儲存貯體存取點使用儲存貯體樣式別名。

以下範例顯示了 S3 on Outposts 存取點的 ARN 格式，其中包括 Outpost 所在區域的 AWS 區域代碼、AWS 帳戶 ID、Outposts ID，以及存取點名稱：

arn:aws:s3-outposts:region:account-id:outpost/outpost-id/accesspoint/accesspoint-name

如需 S3 on Outposts ARN 的詳細資訊，請參閱 Out ARNs posts S3 的資源。

對於 Amazon S3 on Outposts，物件資料始終存放在 Outpost 上。當 AWS 安裝 Outpost 機架時，您的資料將保留在本機 Outpost 上，以滿足資料駐留的要求。您的物件永遠不會離開您的 Outpost，也不會在 AWS 區域 中。由於 AWS Management Console 託管在區域內，您無法使用主控台上傳或管理 Outpost 中的物件。然而，您可以使用 REST API、AWS Command Line Interface (AWS CLI) 以及 AWS SDK 透過存取點上傳和管理您的物件。

下列範例示範如何使用 AWS Command Line Interface (AWS CLI) 和 AWS SDK for Java 下載 (取得) 物件。

下列範例使用 AWS CLI 從 S3 on Outposts 儲存貯體 (s3-outposts:GetObject) 取得名稱為 sample-object.xml 的物件。若要執行此命令，請以您自己的資訊取代每個 user input placeholder。如需此命令的詳細資訊，請參閱 AWS CLI 參考中的 get-object。

aws s3api get-object --bucket arn:aws:s3-outposts:region:123456789012:outpost/op-01ac5d28a6a232904/accesspoint/example-outposts-access-point --key testkey sample-object.xml

下列 S3 on Outposts 範例使用適用於 Java 的開發套件取得物件。若要使用此範例，請以您自己的資訊取代每個 user input placeholder。如需詳細資訊，請參閱《Amazon Simple Storage Service API 參考》中的 GetObject。

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.GetObjectRequest;
import com.amazonaws.services.s3.model.ResponseHeaderOverrides;
import com.amazonaws.services.s3.model.S3Object;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class GetObject {
    public static void main(String[] args) throws IOException {
        String accessPointArn = "*** access point ARN ***";
        String key = "*** Object key ***";

        S3Object fullObject = null, objectPortion = null, headerOverrideObject = null;
        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();

            // Get an object and print its contents.
            System.out.println("Downloading an object");
            fullObject = s3Client.getObject(new GetObjectRequest(accessPointArn, key));
            System.out.println("Content-Type: " + fullObject.getObjectMetadata().getContentType());
            System.out.println("Content: ");
            displayTextInputStream(fullObject.getObjectContent());

            // Get a range of bytes from an object and print the bytes.
            GetObjectRequest rangeObjectRequest = new GetObjectRequest(accessPointArn, key)
                    .withRange(0, 9);
            objectPortion = s3Client.getObject(rangeObjectRequest);
            System.out.println("Printing bytes retrieved.");
            displayTextInputStream(objectPortion.getObjectContent());

            // Get an entire object, overriding the specified response headers, and print the object's content.
            ResponseHeaderOverrides headerOverrides = new ResponseHeaderOverrides()
                    .withCacheControl("No-cache")
                    .withContentDisposition("attachment; filename=example.txt");
            GetObjectRequest getObjectRequestHeaderOverride = new GetObjectRequest(accessPointArn, key)
                    .withResponseHeaders(headerOverrides);
            headerOverrideObject = s3Client.getObject(getObjectRequestHeaderOverride);
            displayTextInputStream(headerOverrideObject.getObjectContent());
        } 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();
        } finally {
            // To ensure that the network connection doesn't remain open, close any open input streams.
            if (fullObject != null) {
                fullObject.close();
            }
            if (objectPortion != null) {
                objectPortion.close();
            }
            if (headerOverrideObject != null) {
                headerOverrideObject.close();
            }
        }
    }

    private static void displayTextInputStream(InputStream input) throws IOException {
        // Read the text input stream one line at a time and display each line.
        BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        String line = null;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        System.out.println();
    }
}