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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 PutObjectRequestputObject
方法与包含对象内容和 PutObjectRequest
对象的 RequestBody
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 DeleteObjectRequestdeleteObject
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 CopyObjectRequestcopyObject
方法,并传递 CopyObjectRequest
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 ListObjectsRequestlistObjects
方法并传递 ListObjectsRequest
对象。此方法返回 ListObjectsResponse
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。