使用 Amazon S3 对象 - Amazon SDK for Java 2.x
上传对象分段上传对象删除对象列出对象更多示例
Amazon Web Services 文档中描述的 Amazon Web Services 服务或功能可能因区域而异。要查看适用于中国区域的差异，请参阅 中国的 Amazon Web Services 服务入门 (PDF)。

本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

使用 Amazon S3 对象

Amazon S3 对象表示一个文件或数据集合。每个对象都必须包含在一个存储桶中。

注意

最佳实践

建议您对 存储桶启用 AbortIncompleteMultipartUploadAmazon S3 生命周期规则。

该规则指示 Amazon S3 中止在启动后没有在指定天数内完成的分段上传。当超过设置的时间限制时，Amazon S3 将中止上传，然后删除未完成的上传数据。

有关更多信息，请参阅《Amazon Simple Storage Service 用户指南》中的使用版本控制的桶生命周期配置。

注意

这些代码片段假设您了解基础知识，并且已使用 设置用于 SDK 的单点登录访问 中的信息配置了默认 Amazon 凭据。

上传对象

构建 PutObjectRequest 并提供存储桶名称和密钥名称。然后，将 S3Client 的 putObject 方法与包含对象内容和 PutObjectRequest 对象的 RequestBody 结合使用。存储桶必须存在，否则服务将返回错误。

导入 

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Random;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.paginators.ListObjectsV2Iterable;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Response;
import software.amazon.awssdk.services.s3.model.S3Object;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteBucketRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
import software.amazon.awssdk.services.s3.model.CompletedMultipartUpload;
import software.amazon.awssdk.services.s3.model.CreateBucketRequest;
import software.amazon.awssdk.services.s3.model.CompletedPart;
import software.amazon.awssdk.services.s3.model.CreateBucketConfiguration;
import software.amazon.awssdk.services.s3.model.UploadPartRequest;
import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
import software.amazon.awssdk.services.s3.waiters.S3Waiter;
import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
import software.amazon.awssdk.services.s3.model.HeadBucketResponse;

代码 

                Region region = Region.US_WEST_2;
                s3 = S3Client.builder()
                                .region(region)
                                .build();

                createBucket(s3, bucketName, region);

                PutObjectRequest objectRequest = PutObjectRequest.builder()
                                .bucket(bucketName)
                                .key(key)
                                .build();

                s3.putObject(objectRequest, RequestBody.fromByteBuffer(getRandomByteBuffer(10_000)));

请参阅 GitHub 上的完整示例。

分段上传对象

使用 S3Client 的 createMultipartUpload 方法获取上传 ID。然后，使用 uploadPart 方法上传每个段。最后，使用 S3Client 的 completeMultipartUpload 方法告知 Amazon S3 合并所有已上传的段并完成上传操作。

导入 

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Random;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.paginators.ListObjectsV2Iterable;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Response;
import software.amazon.awssdk.services.s3.model.S3Object;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteBucketRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
import software.amazon.awssdk.services.s3.model.CompletedMultipartUpload;
import software.amazon.awssdk.services.s3.model.CreateBucketRequest;
import software.amazon.awssdk.services.s3.model.CompletedPart;
import software.amazon.awssdk.services.s3.model.CreateBucketConfiguration;
import software.amazon.awssdk.services.s3.model.UploadPartRequest;
import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
import software.amazon.awssdk.services.s3.waiters.S3Waiter;
import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
import software.amazon.awssdk.services.s3.model.HeadBucketResponse;

代码 

                // First create a multipart upload and get the upload id
                CreateMultipartUploadRequest createMultipartUploadRequest = CreateMultipartUploadRequest.builder()
                                .bucket(bucketName)
                                .key(key)
                                .build();

                CreateMultipartUploadResponse response = s3.createMultipartUpload(createMultipartUploadRequest);
                String uploadId = response.uploadId();
                System.out.println(uploadId);

                // Upload all the different parts of the object
                UploadPartRequest uploadPartRequest1 = UploadPartRequest.builder()
                                .bucket(bucketName)
                                .key(key)
                                .uploadId(uploadId)
                                .partNumber(1).build();

                String etag1 = s3
                                .uploadPart(uploadPartRequest1, RequestBody.fromByteBuffer(getRandomByteBuffer(5 * mB)))
                                .eTag();

                CompletedPart part1 = CompletedPart.builder().partNumber(1).eTag(etag1).build();

                UploadPartRequest uploadPartRequest2 = UploadPartRequest.builder().bucket(bucketName).key(key)
                                .uploadId(uploadId)
                                .partNumber(2).build();
                String etag2 = s3
                                .uploadPart(uploadPartRequest2, RequestBody.fromByteBuffer(getRandomByteBuffer(3 * mB)))
                                .eTag();
                CompletedPart part2 = CompletedPart.builder().partNumber(2).eTag(etag2).build();

                // Finally call completeMultipartUpload operation to tell S3 to merge all
                // uploaded
                // parts and finish the multipart operation.
                CompletedMultipartUpload completedMultipartUpload = CompletedMultipartUpload.builder()
                                .parts(part1, part2)
                                .build();

                CompleteMultipartUploadRequest completeMultipartUploadRequest = CompleteMultipartUploadRequest.builder()
                                .bucket(bucketName)
                                .key(key)
                                .uploadId(uploadId)
                                .multipartUpload(completedMultipartUpload)
                                .build();

                s3.completeMultipartUpload(completeMultipartUploadRequest);

请参阅 GitHub 上的完整示例。

删除对象

构建 DeleteObjectRequest 并提供存储桶名称和密钥名称。使用 S3Client 的 deleteObject 方法，并向其传递要删除的桶和对象的名称。指定的存储桶和对象键必须存在，否则服务将返回错误。

导入 

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Random;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.paginators.ListObjectsV2Iterable;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Request;
import software.amazon.awssdk.services.s3.model.ListObjectsV2Response;
import software.amazon.awssdk.services.s3.model.S3Object;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteObjectRequest;
import software.amazon.awssdk.services.s3.model.DeleteBucketRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadRequest;
import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
import software.amazon.awssdk.services.s3.model.CompletedMultipartUpload;
import software.amazon.awssdk.services.s3.model.CreateBucketRequest;
import software.amazon.awssdk.services.s3.model.CompletedPart;
import software.amazon.awssdk.services.s3.model.CreateBucketConfiguration;
import software.amazon.awssdk.services.s3.model.UploadPartRequest;
import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
import software.amazon.awssdk.services.s3.waiters.S3Waiter;
import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
import software.amazon.awssdk.services.s3.model.HeadBucketResponse;

代码 

                DeleteObjectRequest deleteObjectRequest = DeleteObjectRequest.builder()
                                .bucket(bucketName)
                                .key(key)
                                .build();

                s3.deleteObject(deleteObjectRequest);

请参阅 GitHub 上的完整示例。

复制对象

构建一个 CopyObjectRequest，并提供一个要将此对象负责复制到的存储桶名称、一个 URL 编码的字符串值（请参阅 URlenCoder.code 方法）以及该对象的密钥名称。使用 S3Client 的 copyObject 方法，并传递 CopyObjectRequest 对象。指定的存储桶和对象键必须存在，否则服务将返回错误。

导入 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.CopyObjectRequest;
import software.amazon.awssdk.services.s3.model.CopyObjectResponse;
import software.amazon.awssdk.services.s3.model.S3Exception;

代码 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.CopyObjectRequest;
import software.amazon.awssdk.services.s3.model.CopyObjectResponse;
import software.amazon.awssdk.services.s3.model.S3Exception;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class CopyObject {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <objectKey> <fromBucket> <toBucket>

                Where:
                    objectKey - The name of the object (for example, book.pdf).
                    fromBucket - The S3 bucket name that contains the object (for example, bucket1).
                    toBucket - The S3 bucket to copy the object to (for example, bucket2).
                """;

        if (args.length != 3) {
            System.out.println(usage);
            System.exit(1);
        }

        String objectKey = args[0];
        String fromBucket = args[1];
        String toBucket = args[2];
        System.out.format("Copying object %s from bucket %s to %s\n", objectKey, fromBucket, toBucket);
        Region region = Region.US_EAST_1;
        S3Client s3 = S3Client.builder()
                .region(region)
                .build();

        copyBucketObject(s3, fromBucket, objectKey, toBucket);
        s3.close();
    }

    public static String copyBucketObject(S3Client s3, String fromBucket, String objectKey, String toBucket) {
        CopyObjectRequest copyReq = CopyObjectRequest.builder()
                .sourceBucket(fromBucket)
                .sourceKey(objectKey)
                .destinationBucket(toBucket)
                .destinationKey(objectKey)
                .build();

        try {
            CopyObjectResponse copyRes = s3.copyObject(copyReq);
            return copyRes.copyObjectResult().toString();

        } catch (S3Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        return "";
    }
}

请参阅 GitHub 上的完整示例。

列出对象

构建 ListObjectsRequest 并提供存储桶名称。然后，调用 S3Client 的 listObjects 方法并传递 ListObjectsRequest 对象。此方法返回 ListObjectsResponse，其中包含存储桶中的所有对象。您可以调用此对象的 contents 方法以获取对象的列表。您可以遍历这个列表来显示对象，如以下代码所示。

导入 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.ListObjectsRequest;
import software.amazon.awssdk.services.s3.model.ListObjectsResponse;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.S3Object;
import java.util.List;

代码 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.ListObjectsRequest;
import software.amazon.awssdk.services.s3.model.ListObjectsResponse;
import software.amazon.awssdk.services.s3.model.S3Exception;
import software.amazon.awssdk.services.s3.model.S3Object;
import java.util.List;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class ListObjects {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <bucketName>\s

                Where:
                    bucketName - The Amazon S3 bucket from which objects are read.\s
                """;

        if (args.length != 1) {
            System.out.println(usage);
            System.exit(1);
        }

        String bucketName = args[0];
        Region region = Region.US_EAST_1;
        S3Client s3 = S3Client.builder()
                .region(region)
                .build();

        listBucketObjects(s3, bucketName);
        s3.close();
    }

    public static void listBucketObjects(S3Client s3, String bucketName) {
        try {
            ListObjectsRequest listObjects = ListObjectsRequest
                    .builder()
                    .bucket(bucketName)
                    .build();

            ListObjectsResponse res = s3.listObjects(listObjects);
            List<S3Object> objects = res.contents();
            for (S3Object myValue : objects) {
                System.out.print("\n The name of the key is " + myValue.key());
                System.out.print("\n The object is " + calKb(myValue.size()) + " KBs");
                System.out.print("\n The owner is " + myValue.owner());
            }

        } catch (S3Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    // convert bytes to kbs.
    private static long calKb(Long val) {
        return val / 1024;
    }
}

请参阅 GitHub 上的完整示例。

更多示例

本指南的代码示例部分包含更多使用 Amazon S3 对象的示例，包括如何下载对象。