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与... 一起工作 Amazon S3 预签名 URL - AWS SDK for Java 2.x
Pre-sign 供下载 Pre-sign 用于上传

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与... 一起工作 Amazon S3 预签名 URL

Pre-signed URL 提供对私有 S3 对象的临时访问权限，而无需用户拥有 AWS 凭证或权限。

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。

  • 第 1 部分：Alice 为对象生成预签名 URL。

  • 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();
    }

上 AWS SDK for Java 2.x 提供了预签名 URL 扩展S3AsyncClient，该扩展插件可通过 SDK 异步管道使用预签名 URL 下载对象。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()) 当前不支持预签名 URL 扩展名。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。以后你无法在运行下载时添加它。当您使用S3AsyncClient预签名 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;
下载到文件或字节
Download to file
S3AsyncClient s3AsyncClient = S3AsyncClient.builder()
        .region(Region.US_EAST_1)
        .build();

GetObjectResponse response = s3AsyncClient.presignedUrlExtension()
        .getObject(
            PresignedUrlDownloadRequest.builder()
                .presignedUrl(presignedGetObjectRequest.url())
                .build(),
            Paths.get("/tmp/downloaded-file.bin"))
        .join();

// Or use the consumer builder pattern
GetObjectResponse response = s3AsyncClient.presignedUrlExtension()
        .getObject(
            r -> r.presignedUrl(presignedGetObjectRequest.url()),
            Paths.get("/tmp/downloaded-file.bin"))
        .join();
Download to bytes
S3AsyncClient s3AsyncClient = S3AsyncClient.builder()
        .region(Region.US_EAST_1)
        .build();

ResponseBytes<GetObjectResponse> bytes = s3AsyncClient.presignedUrlExtension()
        .getObject(
            PresignedUrlDownloadRequest.builder()
                .presignedUrl(presignedGetObjectRequest.url())
                .build(),
            AsyncResponseTransformer.toBytes())
        .join();

// Or use the consumer builder pattern
ResponseBytes<GetObjectResponse> bytes = s3AsyncClient.presignedUrlExtension()
        .getObject(
            r -> r.presignedUrl(presignedGetObjectRequest.url()),
            AsyncResponseTransformer.toBytes())
        .join();
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：

Download to file
S3AsyncClient multipartClient = S3AsyncClient.builder()
        .region(Region.US_EAST_1)
        .multipartEnabled(true)
        .multipartConfiguration(c -> c.minimumPartSizeInBytes(8 * 1024 * 1024L))
        .build();

GetObjectResponse response = multipartClient.presignedUrlExtension()
        .getObject(
            PresignedUrlDownloadRequest.builder()
                .presignedUrl(presignedGetObjectRequest.url())
                .build(),
            Paths.get("/tmp/large-file.bin"))
        .join();
Download to bytes
S3AsyncClient multipartClient = S3AsyncClient.builder()
        .region(Region.US_EAST_1)
        .multipartEnabled(true)
        .multipartConfiguration(c -> c.minimumPartSizeInBytes(8 * 1024 * 1024L))
        .build();

ResponseBytes<GetObjectResponse> bytes = multipartClient.presignedUrlExtension()
        .getObject(
            PresignedUrlDownloadRequest.builder()
                .presignedUrl(presignedGetObjectRequest.url())
                .build(),
            AsyncResponseTransformer.toBytes())
        .join();
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 URL 下载对象，并通过TransferListener该链接跟踪进度。

将s3-transfer-manager构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 中央存储库中查找最新的 BOM 版本。

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;
Download to file
S3TransferManager transferManager = S3TransferManager.create();

PresignedFileDownload fileDownload = transferManager.downloadFileWithPresignedUrl(
        PresignedDownloadFileRequest.builder()
            .presignedUrlDownloadRequest(PresignedUrlDownloadRequest.builder()
                .presignedUrl(presignedGetObjectRequest.url())
                .build())
            .destination(Paths.get("/tmp/transfer-download.bin"))
            .addTransferListener(LoggingTransferListener.create())
            .build());

CompletedFileDownload completed = fileDownload.completionFuture().join();
Download to bytes
S3TransferManager transferManager = S3TransferManager.create();

Download<ResponseBytes<GetObjectResponse>> bytesDownload =
        transferManager.downloadWithPresignedUrl(
            PresignedDownloadRequest.<ResponseBytes<GetObjectResponse>>builder()
                .presignedUrlDownloadRequest(PresignedUrlDownloadRequest.builder()
                    .presignedUrl(presignedGetObjectRequest.url())
                    .build())
                .responseTransformer(AsyncResponseTransformer.toBytes())
                .addTransferListener(LoggingTransferListener.create())
                .build());

ResponseBytes<GetObjectResponse> result =
        bytesDownload.completionFuture().join().result();
不支持暂停和恢复

与普通网址不同FileDownload，PresignedFileDownload它不支持暂停和恢复，因为预签名 URL 可能会在暂停传输期间过期。

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。

请查看完整的示例并进行测试 GitHub。

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。

  • 第 1 部分：Alice 生成用于上传对象的预签名 URL。

  • 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);
        }
    }

请查看完整的示例并进行测试 GitHub。