使用Amazon S3对象 - Amazon SDK for Java
上传对象分段上传对象下载对象删除对象复制对象列出对象
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。

现在，您可以使用Amazon S3转移经理（开发人员预览版）中的Amazon SDK for Java2.x 用于加速文件传输。试试一下然后告诉我们您的想法！顺便说一句，Amazon SDK for Java正在招聘团队软件开发工程师！

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 。使用版本控制的存储桶生命周期配置中的Amazon Simple Storage Service用户指南。

注意

这些代码片段假设您了解基本资料，并且已配置默认值Amazon使用中的信息的凭据设置默认凭据和区域.

上传对象

构建 PutObjectRequest 并提供存储桶名称和密钥名称。然后使用 S3ClientputObject使用的方法RequestBody其中包含对象内容和PutObjectRequest对象。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 S3ClientcreateMultipartUpload方法获取上传 ID。然后，使用 uploadPart 方法上传每个段。最后，使用 S3ClientcompleteMultipartUpload要告诉的方法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。

下载对象

构建 GetObjectRequest 并提供存储桶名称和密钥名称。使用 S3ClientgetObject方法，将它传递GetObjectRequest对象和ResponseTransformer对象。ResponseTransformer 将创建一个将响应内容写入到指定的文件或流的响应处理程序。

以下示例指定要将对象内容写入到的文件名。

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 

        GetObjectRequest getObjectRequest = GetObjectRequest.builder()
                .bucket(bucketName)
                .key(key)
                .build();

        s3.getObject(getObjectRequest);

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 S3ClientdeleteObject方法，并向其传递要删除的存储桶和对象的名称。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 S3ClientcopyObject方法，然后通过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;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

代码 

    public static String copyBucketObject (S3Client s3, String fromBucket, String objectKey, String toBucket) {

        String encodedUrl = null;
        try {
            encodedUrl = URLEncoder.encode(fromBucket + "/" + objectKey, StandardCharsets.UTF_8.toString());
        } catch (UnsupportedEncodingException e) {
            System.out.println("URL could not be encoded: " + e.getMessage());
        }
        CopyObjectRequest copyReq = CopyObjectRequest.builder()
                .copySource(encodedUrl)
                .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 S3ClientlistObjects方法然后通过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;
import java.util.ListIterator;

代码 

    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 (ListIterator iterVals = objects.listIterator(); iterVals.hasNext(); ) {
                S3Object myValue = (S3Object) iterVals.next();
                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。