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和... 一起工作 Amazon S3 预签名的 URL
Pre-signed URL 提供对私有 S3 对象的临时访问,无需用户拥有 AWS 证书或权限。
例如,假设 Alice 有权访问 S3 对象,并希望临时与 Bob 分享对该对象的访问权限。Alice 可以生成预签名的 GET 请求来与 Bob 分享,这样 Bob 就可以下载该对象而无需访问 Alice 的凭证。您可以为 HTTP GET 和 HTTP PUT 请求生成预签名 URL。
为对象生成预签名 URL,然后下载对象(GET 请求)
以下示例由两部分组成。
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第 1 部分:Alice 为对象生成预签名 URL。
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第 2 部分:Bob 使用预签名 URL 下载对象。
第 1 部分:生成 URL
Alice 在 S3 桶中已有一个对象。她使用以下代码生成一个 URL 字符串,Bob 可以在后续的 GET 请求中使用该字符串。
import com.example.s3.util.PresignUrlUtils; import org.slf4j.Logger; import software.amazon.awssdk.http.HttpExecuteRequest; import software.amazon.awssdk.http.HttpExecuteResponse; import software.amazon.awssdk.http.SdkHttpClient; import software.amazon.awssdk.http.SdkHttpMethod; import software.amazon.awssdk.http.SdkHttpRequest; import software.amazon.awssdk.http.apache.ApacheHttpClient; import software.amazon.awssdk.services.s3.S3Client; import software.amazon.awssdk.services.s3.model.GetObjectRequest; import software.amazon.awssdk.services.s3.model.S3Exception; import software.amazon.awssdk.services.s3.presigner.S3Presigner; import software.amazon.awssdk.services.s3.presigner.model.GetObjectPresignRequest; import software.amazon.awssdk.services.s3.presigner.model.PresignedGetObjectRequest; import software.amazon.awssdk.utils.IoUtils; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URISyntaxException; import java.net.URL; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; import java.nio.file.Paths; import java.time.Duration; import java.util.UUID;
/* Create a pre-signed URL to download an object in a subsequent GET request. */ public String createPresignedGetUrl(String bucketName, String keyName) { try (S3Presigner presigner = S3Presigner.create()) { GetObjectRequest objectRequest = GetObjectRequest.builder() .bucket(bucketName) .key(keyName) .build(); GetObjectPresignRequest presignRequest = GetObjectPresignRequest.builder() .signatureDuration(Duration.ofMinutes(10)) // The URL will expire in 10 minutes. .getObjectRequest(objectRequest) .build(); PresignedGetObjectRequest presignedRequest = presigner.presignGetObject(presignRequest); logger.info("Presigned URL: [{}]", presignedRequest.url().toString()); logger.info("HTTP method: [{}]", presignedRequest.httpRequest().method()); return presignedRequest.url().toExternalForm(); } }
第 2 部分:下载对象
Bob 使用以下代码选项之一来下载对象。或者,他可以使用浏览器来执行 GET 请求。
/* Use the JDK HttpURLConnection (since v1.1) class to do the download. */ public byte[] useHttpUrlConnectionToGet(String presignedUrlString) { ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); // Capture the response body to a byte array. try { URL presignedUrl = new URL(presignedUrlString); HttpURLConnection connection = (HttpURLConnection) presignedUrl.openConnection(); connection.setRequestMethod("GET"); // Download the result of executing the request. try (InputStream content = connection.getInputStream()) { IoUtils.copy(content, byteArrayOutputStream); } logger.info("HTTP response code is " + connection.getResponseCode()); } catch (S3Exception | IOException e) { logger.error(e.getMessage(), e); } return byteArrayOutputStream.toByteArray(); }
/* Use the JDK HttpClient (since v11) class to do the download. */ public byte[] useHttpClientToGet(String presignedUrlString) { ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); // Capture the response body to a byte array. HttpRequest.Builder requestBuilder = HttpRequest.newBuilder(); HttpClient httpClient = HttpClient.newHttpClient(); try { URL presignedUrl = new URL(presignedUrlString); HttpResponse<InputStream> response = httpClient.send(requestBuilder .uri(presignedUrl.toURI()) .GET() .build(), HttpResponse.BodyHandlers.ofInputStream()); IoUtils.copy(response.body(), byteArrayOutputStream); logger.info("HTTP response code is " + response.statusCode()); } catch (URISyntaxException | InterruptedException | IOException e) { logger.error(e.getMessage(), e); } return byteArrayOutputStream.toByteArray(); }
/* Use the AWS SDK for Java SdkHttpClient class to do the download. */ public byte[] useSdkHttpClientToGet(String presignedUrlString) { ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); // Capture the response body to a byte array. try { URL presignedUrl = new URL(presignedUrlString); SdkHttpRequest request = SdkHttpRequest.builder() .method(SdkHttpMethod.GET) .uri(presignedUrl.toURI()) .build(); HttpExecuteRequest executeRequest = HttpExecuteRequest.builder() .request(request) .build(); try (SdkHttpClient sdkHttpClient = ApacheHttpClient.create()) { HttpExecuteResponse response = sdkHttpClient.prepareRequest(executeRequest).call(); response.responseBody().ifPresentOrElse( abortableInputStream -> { try { IoUtils.copy(abortableInputStream, byteArrayOutputStream); } catch (IOException e) { throw new RuntimeException(e); } }, () -> logger.error("No response body.")); logger.info("HTTP Response code is {}", response.httpResponse().statusCode()); } } catch (URISyntaxException | IOException e) { logger.error(e.getMessage(), e); } return byteArrayOutputStream.toByteArray(); }
为通过 SDK 异步管道使用预签名 URL 下载对象 AWS SDK for Java 2.x 提供了预签名 URL 的预签名 URL 扩展。S3AsyncClient使用访问扩展程序S3AsyncClient.presignedUrlExtension()。此功能在 SDK 版本2.48.0及更高版本中可用。
CRT 客户端限制
S AWS CRT-based 3 客户端 (S3AsyncClient.crtBuilder()) 目前不支持预签名的 URL 扩展。请改用 S3AsyncClient.builder()。
校验和模式要求
要验证数据完整性,请在生成预签名 URL GetObjectRequest 时设置为checksumMode(ChecksumMode.ENABLED)。在预签名时指定校验和模式。以后运行下载时无法将其添加。当您使用S3AsyncClient预签名的 URL 扩展时,SDK 会自动发送所需的标x-amz-checksum-mode头。
import java.nio.file.Paths; import software.amazon.awssdk.core.ResponseBytes; import software.amazon.awssdk.core.async.AsyncResponseTransformer; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.s3.S3AsyncClient; import software.amazon.awssdk.services.s3.model.GetObjectResponse; import software.amazon.awssdk.services.s3.presignedurl.model.PresignedUrlDownloadRequest;
下载到文件或下载到字节
大文件分段下载
要并行下载大型对象,请在客户端multipartEnabled(true)上设置:
使用 Amazon S3 传输管理器
借助 Amazon S3 传输管理器,您可以使用预签名的 URL 下载对象,并进行TransferListener进度跟踪。
将s3-transfer-manager工件添加到您的项目中:
<dependencyManagement> <dependencies> <dependency> <groupId>software.amazon.awssdk</groupId> <artifactId>bom</artifactId> <version>2.48.01</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>software.amazon.awssdk</groupId> <artifactId>s3-transfer-manager</artifactId> </dependency> </dependencies>
1 在 Maven 中央存储库
import java.nio.file.Paths; import software.amazon.awssdk.core.ResponseBytes; import software.amazon.awssdk.core.async.AsyncResponseTransformer; import software.amazon.awssdk.services.s3.model.GetObjectResponse; import software.amazon.awssdk.services.s3.presignedurl.model.PresignedUrlDownloadRequest; import software.amazon.awssdk.transfer.s3.S3TransferManager; import software.amazon.awssdk.transfer.s3.model.CompletedFileDownload; import software.amazon.awssdk.transfer.s3.model.Download; import software.amazon.awssdk.transfer.s3.model.PresignedDownloadFileRequest; import software.amazon.awssdk.transfer.s3.model.PresignedDownloadRequest; import software.amazon.awssdk.transfer.s3.model.PresignedFileDownload; import software.amazon.awssdk.transfer.s3.progress.LoggingTransferListener;
不支持暂停和恢复
与普通网址不同FileDownload,PresignedFileDownload不支持暂停和恢复,因为预签名的 URL 可能会在暂停的传输期间过期。
有关 Amazon S3 传输管理器的更多信息,包括配置选项和其他示例,请参阅使用 Amazon S3 Transfer Manager 传输文件和目录。
查看完整示例
为上传生成预签名 URL,然后上传文件(PUT 请求)
以下示例由两部分组成。
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第 1 部分:Alice 生成用于上传对象的预签名 URL。
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第 2 部分:Bob 使用预签名 URL 上传文件。
第 1 部分:生成 URL
Alice 已有一个 S3 桶。她使用以下代码生成一个 URL 字符串,Bob 可以在后续的 PUT 请求中使用该字符串。
import com.example.s3.util.PresignUrlUtils; import org.slf4j.Logger; import software.amazon.awssdk.core.internal.sync.FileContentStreamProvider; import software.amazon.awssdk.http.HttpExecuteRequest; import software.amazon.awssdk.http.HttpExecuteResponse; import software.amazon.awssdk.http.SdkHttpClient; import software.amazon.awssdk.http.SdkHttpMethod; import software.amazon.awssdk.http.SdkHttpRequest; import software.amazon.awssdk.http.apache.ApacheHttpClient; import software.amazon.awssdk.services.s3.S3Client; import software.amazon.awssdk.services.s3.model.PutObjectRequest; import software.amazon.awssdk.services.s3.model.S3Exception; import software.amazon.awssdk.services.s3.presigner.S3Presigner; import software.amazon.awssdk.services.s3.presigner.model.PresignedPutObjectRequest; import software.amazon.awssdk.services.s3.presigner.model.PutObjectPresignRequest; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.io.RandomAccessFile; import java.net.HttpURLConnection; import java.net.URISyntaxException; import java.net.URL; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import java.nio.file.Path; import java.nio.file.Paths; import java.time.Duration; import java.util.Map; import java.util.UUID;
/* Create a presigned URL to use in a subsequent PUT request */ public String createPresignedUrl(String bucketName, String keyName, Map<String, String> metadata) { try (S3Presigner presigner = S3Presigner.create()) { PutObjectRequest objectRequest = PutObjectRequest.builder() .bucket(bucketName) .key(keyName) .metadata(metadata) .build(); PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder() .signatureDuration(Duration.ofMinutes(10)) // The URL expires in 10 minutes. .putObjectRequest(objectRequest) .build(); PresignedPutObjectRequest presignedRequest = presigner.presignPutObject(presignRequest); String myURL = presignedRequest.url().toString(); logger.info("Presigned URL to upload a file to: [{}]", myURL); logger.info("HTTP method: [{}]", presignedRequest.httpRequest().method()); return presignedRequest.url().toExternalForm(); } }
第 2 部分:上传文件对象
Bob 使用以下三个代码选项之一来上传文件。
/* Use the JDK HttpURLConnection (since v1.1) class to do the upload. */ public void useHttpUrlConnectionToPut(String presignedUrlString, File fileToPut, Map<String, String> metadata) { logger.info("Begin [{}] upload", fileToPut.toString()); try { URL presignedUrl = new URL(presignedUrlString); HttpURLConnection connection = (HttpURLConnection) presignedUrl.openConnection(); connection.setDoOutput(true); metadata.forEach((k, v) -> connection.setRequestProperty("x-amz-meta-" + k, v)); connection.setRequestMethod("PUT"); OutputStream out = connection.getOutputStream(); try (RandomAccessFile file = new RandomAccessFile(fileToPut, "r"); FileChannel inChannel = file.getChannel()) { ByteBuffer buffer = ByteBuffer.allocate(8192); //Buffer size is 8k while (inChannel.read(buffer) > 0) { buffer.flip(); for (int i = 0; i < buffer.limit(); i++) { out.write(buffer.get()); } buffer.clear(); } } catch (IOException e) { logger.error(e.getMessage(), e); } out.close(); connection.getResponseCode(); logger.info("HTTP response code is " + connection.getResponseCode()); } catch (S3Exception | IOException e) { logger.error(e.getMessage(), e); } }
/* Use the JDK HttpClient (since v11) class to do the upload. */ public void useHttpClientToPut(String presignedUrlString, File fileToPut, Map<String, String> metadata) { logger.info("Begin [{}] upload", fileToPut.toString()); HttpRequest.Builder requestBuilder = HttpRequest.newBuilder(); metadata.forEach((k, v) -> requestBuilder.header("x-amz-meta-" + k, v)); HttpClient httpClient = HttpClient.newHttpClient(); try { final HttpResponse<Void> response = httpClient.send(requestBuilder .uri(new URL(presignedUrlString).toURI()) .PUT(HttpRequest.BodyPublishers.ofFile(Path.of(fileToPut.toURI()))) .build(), HttpResponse.BodyHandlers.discarding()); logger.info("HTTP response code is " + response.statusCode()); } catch (URISyntaxException | InterruptedException | IOException e) { logger.error(e.getMessage(), e); } }
/* Use the AWS SDK for Java V2 SdkHttpClient class to do the upload. */ public void useSdkHttpClientToPut(String presignedUrlString, File fileToPut, Map<String, String> metadata) { logger.info("Begin [{}] upload", fileToPut.toString()); try { URL presignedUrl = new URL(presignedUrlString); SdkHttpRequest.Builder requestBuilder = SdkHttpRequest.builder() .method(SdkHttpMethod.PUT) .uri(presignedUrl.toURI()); // Add headers metadata.forEach((k, v) -> requestBuilder.putHeader("x-amz-meta-" + k, v)); // Finish building the request. SdkHttpRequest request = requestBuilder.build(); HttpExecuteRequest executeRequest = HttpExecuteRequest.builder() .request(request) .contentStreamProvider(new FileContentStreamProvider(fileToPut.toPath())) .build(); try (SdkHttpClient sdkHttpClient = ApacheHttpClient.create()) { HttpExecuteResponse response = sdkHttpClient.prepareRequest(executeRequest).call(); logger.info("Response code: {}", response.httpResponse().statusCode()); } } catch (URISyntaxException | IOException e) { logger.error(e.getMessage(), e); } }
查看完整示例
将请求字段作为 URL 查询参数
一些请求字段位于GetObjectRequestrequestPayer、aclmetadataserverSideEncryption、和storageClass映射到x-amz-*标题。当您对设置其中一个字段的请求进行预签名时,签名会覆盖标头。但是,S3Presigner
预签名 URL 的调用者必须在请求中发送相同的x-amz-*标头。否则,亚马逊 S3 将返回SignatureDoesNotMatch。可以设置自定义标头的 HTTP 客户端直接发送这些标头。例如,前面显示的HttpURLConnectionHttpClient、和SdkHttpClient
要使 URL 在没有额外标头的情况下正常工作,请将该值作为签名查询参数传递,而不是设置键入字段。使用 p ut RawQueryParameter
Pre-sign 由请求者付款的 GET 请求
以下示例GetObjectRequest使用请求者付款设置为生成预签名 URL。由于该值是查询参数,因此任何调用者都可以在不发送x-amz-request-payer标头的情况下使用该 URL。
try (S3Presigner presigner = S3Presigner.create()) { GetObjectRequest getObjectRequest = GetObjectRequest.builder() .bucket("amzn-s3-demo-bucket") .key("example-key") .overrideConfiguration(o -> o.putRawQueryParameter("x-amz-request-payer", "requester")) .build(); GetObjectPresignRequest presignRequest = GetObjectPresignRequest.builder() .signatureDuration(Duration.ofMinutes(10)) .getObjectRequest(getObjectRequest) .build(); PresignedGetObjectRequest presigned = presigner.presignGetObject(presignRequest); logger.info("Pre-signed URL: [{}]", presigned.url()); // Confirm the URL requires no headers at request time: logger.info("Signed headers: {}", presigned.signedHeaders().keySet()); // [host] }
Pre-sign 包含元数据的 PUT 请求
以下示例PutObjectRequest使用两个元数据值作为签名查询参数为生成预签名 URL。由于这些值是查询参数,因此任何调用者都可以在不发送x-amz-meta-*标头的情况下使用 URL。
try (S3Presigner presigner = S3Presigner.create()) { PutObjectRequest putObjectRequest = PutObjectRequest.builder() .bucket("amzn-s3-demo-bucket") .key("example-key") .overrideConfiguration(o -> o .putRawQueryParameter("x-amz-meta-author", "alice") .putRawQueryParameter("x-amz-meta-purpose", "demo")) .build(); PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder() .signatureDuration(Duration.ofMinutes(10)) .putObjectRequest(putObjectRequest) .build(); PresignedPutObjectRequest presigned = presigner.presignPutObject(presignRequest); logger.info("Pre-signed URL: [{}]", presigned.url()); // Confirm the URL requires no headers at upload time: logger.info("Signed headers: {}", presigned.signedHeaders().keySet()); // [host] }
Pre-sign 一个 PUT 请求并上传一个文件
以下示例显示了完整的工作流程:一种使用您提供的任何x-amz-*名称和值作为地图对 PUT 请求进行预签名的方法,以及一种用于上传文件的方法。SdkHttpClient由于这些值已经是签名网址的一部分,因此上传方法不会设置任何x-amz-*标头。相比之下,之前的上传示例明确设置了x-amz-meta-*标题。
import com.example.s3.util.PresignUrlUtils; import org.slf4j.Logger; import software.amazon.awssdk.awscore.AwsRequestOverrideConfiguration; import software.amazon.awssdk.core.internal.sync.FileContentStreamProvider; import software.amazon.awssdk.http.HttpExecuteRequest; import software.amazon.awssdk.http.HttpExecuteResponse; import software.amazon.awssdk.http.SdkHttpClient; import software.amazon.awssdk.http.SdkHttpMethod; import software.amazon.awssdk.http.SdkHttpRequest; import software.amazon.awssdk.http.apache.ApacheHttpClient; import software.amazon.awssdk.services.s3.S3Client; import software.amazon.awssdk.services.s3.model.PutObjectRequest; import software.amazon.awssdk.services.s3.presigner.S3Presigner; import software.amazon.awssdk.services.s3.presigner.model.PresignedPutObjectRequest; import software.amazon.awssdk.services.s3.presigner.model.PutObjectPresignRequest; import java.io.File; import java.io.IOException; import java.net.URISyntaxException; import java.net.URL; import java.nio.file.Paths; import java.time.Duration; import java.util.Map; import java.util.UUID;
生成 URL。
/** * Creates a presigned URL to use in a subsequent HTTP PUT request. The code adds query parameters * to the request instead of using headers. By using query parameters, you do not need to add the * the parameters as headers when the PUT request is eventually sent. * * @param bucketName Bucket name where the object will be uploaded. * @param keyName Key name of the object that will be uploaded. * @param queryParams Query string parameters to be added to the presigned URL. * @return */ public String createPresignedUrl(String bucketName, String keyName, Map<String, String> queryParams) { try (S3Presigner presigner = S3Presigner.create()) { // Create an override configuration to store the query parameters. AwsRequestOverrideConfiguration.Builder overrideConfigurationBuilder = AwsRequestOverrideConfiguration.builder(); queryParams.forEach(overrideConfigurationBuilder::putRawQueryParameter); PutObjectRequest objectRequest = PutObjectRequest.builder() .bucket(bucketName) .key(keyName) .overrideConfiguration(overrideConfigurationBuilder.build()) // Add the override configuration. .build(); PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder() .signatureDuration(Duration.ofMinutes(10)) // The URL expires in 10 minutes. .putObjectRequest(objectRequest) .build(); PresignedPutObjectRequest presignedRequest = presigner.presignPutObject(presignRequest); String myURL = presignedRequest.url().toString(); logger.info("Presigned URL to upload a file to: [{}]", myURL); logger.info("HTTP method: [{}]", presignedRequest.httpRequest().method()); return presignedRequest.url().toExternalForm(); } }
使用上传文件SdkHttpClient。
/** * Use the AWS SDK for Java V2 SdkHttpClient class to execute the PUT request. Since the * URL contains the query parameters, no headers are needed for metadata, SSE settings, or ACL settings. * * @param presignedUrlString The URL for the PUT request. * @param fileToPut File to uplaod */ public void useSdkHttpClientToPut(String presignedUrlString, File fileToPut) { logger.info("Begin [{}] upload", fileToPut.toString()); try { URL presignedUrl = new URL(presignedUrlString); SdkHttpRequest.Builder requestBuilder = SdkHttpRequest.builder() .method(SdkHttpMethod.PUT) .uri(presignedUrl.toURI()); SdkHttpRequest request = requestBuilder.build(); HttpExecuteRequest executeRequest = HttpExecuteRequest.builder() .request(request) .contentStreamProvider(new FileContentStreamProvider(fileToPut.toPath())) .build(); try (SdkHttpClient sdkHttpClient = ApacheHttpClient.create()) { HttpExecuteResponse response = sdkHttpClient.prepareRequest(executeRequest).call(); logger.info("Response code: {}", response.httpResponse().statusCode()); } } catch (URISyntaxException | IOException e) { logger.error(e.getMessage(), e); } }
查看完整示例
检查预签名请求需要哪些标头
要检查特定的预签名请求需要调用者发送哪些标头,请在返回的请求上调用 x-amz-*名称都是调用者必须发送的标头。如果要从要求中删除标题,请传递其值,putRawQueryParameter而不是设置键入的字段。