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# 使用 Amazon S3 Transfer Manager 传输文件和目录
<a name="transfer-manager"></a>

Amazon S3 Transfer Manager 是针对 AWS SDK for Java 2.x的一款开源高级文件传输工具。可以使用它将文件和目录传入和传出 Amazon Simple Storage Service (Amazon S3)。

在[基于AWS CRT 的 S3 客户端](crt-based-s3-client.md)或[启用了分段的基于 Java 的标准 S3 异步客户端](s3-async-client-multipart.md)基础上构建时，S3 Transfer Manager 可以利用[分段上传 API](https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpuoverview.html) 和[字节范围提取](https://docs.aws.amazon.com/AmazonS3/latest/userguide/optimizing-performance-guidelines.html#optimizing-performance-guidelines-get-range)等性能改进。

使用 S3 Transfer Manager，您还可以实时监控传输进度，并暂停传输以便日后执行。

## 开始使用
<a name="transfer-manager-prerequisites"></a>

### 将依赖项添加到构建文件中
<a name="transfer-manager-add-dependency"></a>

要在使用 S3 Transfer Manager 时获得增强的分段性能，请使用必要的依赖项配置构建文件。

------
#### [ Use the AWS CRT-based S3 client ]

```
<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>bom</artifactId>
            <version>2.27.211</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
<dependencies>
    <dependency>
        <groupId>software.amazon.awssdk</groupId>
        <artifactId>s3-transfer-manager</artifactId>
    </dependency>
    <dependency>
        <groupId>software.amazon.awssdk.crt</groupId>
        <artifactId>aws-crt</artifactId>
        <version>0.29.1432</version>
    </dependency>
</dependencies>
```

1 [最新版本](https://central.sonatype.com/artifact/software.amazon.awssdk/bom)。2[最新版本](https://central.sonatype.com/artifact/software.amazon.awssdk.crt/aws-crt)。

------
#### [ Use the Java-based S3 async client ]

```
<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>bom</artifactId>
            <version>2.27.211</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 [最新版本](https://central.sonatype.com/artifact/software.amazon.awssdk/bom)。

------

### 创建 S3 Transfer Manager 的实例
<a name="transfer-manager-create"></a>

要启用并行传输，必须传入 AWS 基于 CRT 的 S3 客户端或启用了多部分功能的基于 Java 的 S3 异步客户端。以下示例演示如何使用自定义设置来配置 S3 Transfer Manager。

------
#### [ Use the AWS CRT-based S3 client ]

```
        S3AsyncClient s3AsyncClient = S3AsyncClient.crtBuilder()
                .credentialsProvider(DefaultCredentialsProvider.create())
                .region(Region.US_EAST_1)
                .targetThroughputInGbps(20.0)
                .minimumPartSizeInBytes(8 * MB)
                .build();

        S3TransferManager transferManager = S3TransferManager.builder()
                .s3Client(s3AsyncClient)
                .build();
```

------
#### [ Use the Java-based S3 async client ]

如果构建文件中未包含 `aws-crt` 依赖项，则 S3 Transfer Manager 将在适用于 Java 的 SDK 2.x 中使用的基于 Java 的标准 S3 异步客户端的基础上构建。

**S3 客户端的自定义配置 - 需要启用分段功能**

```
        S3AsyncClient s3AsyncClient = S3AsyncClient.builder()
                .multipartEnabled(true)
                .credentialsProvider(DefaultCredentialsProvider.create())
                .region(Region.US_EAST_1)
                .build();

        S3TransferManager transferManager = S3TransferManager.builder()
                .s3Client(s3AsyncClient)
                .build();
```

**没有 S3 客户端配置 - 自动启用分段支持**

```
S3TransferManager transferManager = S3TransferManager.create();
```

------

## 将文件上传到 S3 桶
<a name="transfer-manager-upload"></a>

以下示例显示了文件上传示例 [LoggingTransferListener](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/progress/LoggingTransferListener.html)，以及记录上传进度的可选用法。

要使用 S3 Transfer Manager 将文件上传到 Amazon S3，请将 [https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/UploadFileRequest.html](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/UploadFileRequest.html) 对象传递给 `S3TransferManager` 的 [uploadFile](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/S3TransferManager.html#uploadFile(software.amazon.awssdk.transfer.s3.model.UploadFileRequest)) 方法。

从该`uploadFile`方法返回的[FileUpload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/FileUpload.html)对象表示上传过程。请求完成后，该[CompletedFileUpload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CompletedFileUpload.html)对象将包含有关上传的信息。

```
    public void trackUploadFile(S3TransferManager transferManager, String bucketName,
                             String key, URI filePathURI) {
        UploadFileRequest uploadFileRequest = UploadFileRequest.builder()
                .putObjectRequest(b -> b.bucket(bucketName).key(key))
                .addTransferListener(LoggingTransferListener.create())  // Add listener.
                .source(Paths.get(filePathURI))
                .build();

        FileUpload fileUpload = transferManager.uploadFile(uploadFileRequest);

        fileUpload.completionFuture().join();
        /*
            The SDK provides a LoggingTransferListener implementation of the TransferListener interface.
            You can also implement the interface to provide your own logic.

            Configure log4J2 with settings such as the following.
                <Configuration status="WARN">
                    <Appenders>
                        <Console name="AlignedConsoleAppender" target="SYSTEM_OUT">
                            <PatternLayout pattern="%m%n"/>
                        </Console>
                    </Appenders>

                    <Loggers>
                        <logger name="software.amazon.awssdk.transfer.s3.progress.LoggingTransferListener" level="INFO" additivity="false">
                            <AppenderRef ref="AlignedConsoleAppender"/>
                        </logger>
                    </Loggers>
                </Configuration>

            Log4J2 logs the progress. The following is example output for a 21.3 MB file upload.
                Transfer initiated...
                |                    | 0.0%
                |====                | 21.1%
                |============        | 60.5%
                |====================| 100.0%
                Transfer complete!
        */
    }
```

### 导入
<a name="transfer-manager-upload-imports"></a>

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedFileUpload;
import software.amazon.awssdk.transfer.s3.model.FileUpload;
import software.amazon.awssdk.transfer.s3.model.UploadFileRequest;
import software.amazon.awssdk.transfer.s3.progress.LoggingTransferListener;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Paths;
import java.util.UUID;
```

## 从 S3 桶下载文件
<a name="transfer-manager-download"></a>

以下示例显示了下载示例以及记录下载进度的可选用法。[LoggingTransferListener](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/progress/LoggingTransferListener.html)

要使用 S3 传输管理器从 S3 存储桶下载对象，请生成一个[DownloadFileRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/DownloadFileRequest.html)对象并将其传递给 [downloadFile](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/S3TransferManager.html#downloadFile(software.amazon.awssdk.transfer.s3.model.DownloadFileRequest)) 方法。

的`downloadFile`方法返回`S3TransferManager`的[FileDownload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/FileDownload.html)对象表示文件传输。下载完成后，[CompletedFileDownload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CompletedFileDownload.html)包含对下载相关信息的访问权限。

```
    public void trackDownloadFile(S3TransferManager transferManager, String bucketName,
                             String key, String downloadedFileWithPath) {
        DownloadFileRequest downloadFileRequest = DownloadFileRequest.builder()
                .getObjectRequest(b -> b.bucket(bucketName).key(key))
                .addTransferListener(LoggingTransferListener.create())  // Add listener.
                .destination(Paths.get(downloadedFileWithPath))
                .build();

        FileDownload downloadFile = transferManager.downloadFile(downloadFileRequest);

        CompletedFileDownload downloadResult = downloadFile.completionFuture().join();
        /*
            The SDK provides a LoggingTransferListener implementation of the TransferListener interface.
            You can also implement the interface to provide your own logic.

            Configure log4J2 with settings such as the following.
                <Configuration status="WARN">
                    <Appenders>
                        <Console name="AlignedConsoleAppender" target="SYSTEM_OUT">
                            <PatternLayout pattern="%m%n"/>
                        </Console>
                    </Appenders>

                    <Loggers>
                        <logger name="software.amazon.awssdk.transfer.s3.progress.LoggingTransferListener" level="INFO" additivity="false">
                            <AppenderRef ref="AlignedConsoleAppender"/>
                        </logger>
                    </Loggers>
                </Configuration>

            Log4J2 logs the progress. The following is example output for a 21.3 MB file download.
                Transfer initiated...
                |=======             | 39.4%
                |===============     | 78.8%
                |====================| 100.0%
                Transfer complete!
        */
    }
```

### 导入
<a name="transfer-manager-download-import"></a>

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.exception.SdkException;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedFileDownload;
import software.amazon.awssdk.transfer.s3.model.DownloadFileRequest;
import software.amazon.awssdk.transfer.s3.model.FileDownload;
import software.amazon.awssdk.transfer.s3.progress.LoggingTransferListener;

import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.UUID;
```

## 将 Amazon S3 对象复制到另一个桶。
<a name="transfer-manager-copy"></a>

以下示例演示如何使用 S3 Transfer Manager 复制对象。

要开始将对象从 S3 存储桶复制到另一个存储桶，请创建一个基本[CopyObjectRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/s3/model/CopyObjectRequest.html)实例。

接下来，将基本内容封装`CopyObjectRequest`在 S3 传输管理器可以使用的文件中。[CopyRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CopyRequest.html)

`S3TransferManager` 的 `copy` 方法返回的 `Copy` 对象表示复制进程。复制过程完成后，该[CompletedCopy](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CompletedCopy.html)对象将包含有关响应的详细信息。

```
    public String copyObject(S3TransferManager transferManager, String bucketName,
            String key, String destinationBucket, String destinationKey) {
        CopyObjectRequest copyObjectRequest = CopyObjectRequest.builder()
                .sourceBucket(bucketName)
                .sourceKey(key)
                .destinationBucket(destinationBucket)
                .destinationKey(destinationKey)
                .build();

        CopyRequest copyRequest = CopyRequest.builder()
                .copyObjectRequest(copyObjectRequest)
                .build();

        Copy copy = transferManager.copy(copyRequest);

        CompletedCopy completedCopy = copy.completionFuture().join();
        return completedCopy.response().copyObjectResult().eTag();
    }
```

**注意**  
要使用 S3 传输管理器执行跨区域复制，请在 AWS 基于 CRT 的 S3 客户端生成器`crossRegionAccessEnabled`上启用，如以下代码段所示。  

```
S3AsyncClient s3AsyncClient = S3AsyncClient.crtBuilder()
                .crossRegionAccessEnabled(true)
                .build();

S3TransferManager transferManager = S3TransferManager.builder()
                .s3Client(s3AsyncClient)
                .build();
```

### 导入
<a name="transfer-manager-copy-import"></a>

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.services.s3.model.CopyObjectRequest;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedCopy;
import software.amazon.awssdk.transfer.s3.model.Copy;
import software.amazon.awssdk.transfer.s3.model.CopyRequest;

import java.util.UUID;
```

## 将本地目录上传到 S3 桶
<a name="transfer-manager-upload_directory"></a>

以下示例演示如何将本地目录上传到 S3。

首先调用`S3TransferManager`实例的 [uploadDirectory](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/S3TransferManager.html#uploadDirectory(software.amazon.awssdk.transfer.s3.model.UploadDirectoryRequest)) 方法，传入。[UploadDirectoryRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/UploadDirectoryRequest.html)

该[DirectoryUpload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/DirectoryUpload.html)对象表示上传过程，该过程会在请求完成[CompletedDirectoryUpload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CompletedDirectoryUpload.html)时生成。`CompleteDirectoryUpload` 对象包含有关传输结果的信息，包括哪些文件传输失败。

```
    public Integer uploadDirectory(S3TransferManager transferManager,
            URI sourceDirectory, String bucketName) {
        DirectoryUpload directoryUpload = transferManager.uploadDirectory(UploadDirectoryRequest.builder()
                .source(Paths.get(sourceDirectory))
                .bucket(bucketName)
                .build());

        CompletedDirectoryUpload completedDirectoryUpload = directoryUpload.completionFuture().join();
        completedDirectoryUpload.failedTransfers()
                .forEach(fail -> logger.warn("Object [{}] failed to transfer", fail.toString()));
        return completedDirectoryUpload.failedTransfers().size();
    }
```

### 导入
<a name="transfer-manager-upload_directory-import"></a>

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.services.s3.model.ObjectIdentifier;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedDirectoryUpload;
import software.amazon.awssdk.transfer.s3.model.DirectoryUpload;
import software.amazon.awssdk.transfer.s3.model.UploadDirectoryRequest;

import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Paths;
import java.util.UUID;
```

## 将 S3 桶对象下载到本地目录
<a name="transfer-manager-download_directory"></a>

您可以将 S3 桶中的对象下载到本地目录，如以下示例所示。

要将 S3 存储桶中的对象下载到本地目录，请首先调用传输管理器的 [downloadDirectory](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/S3TransferManager.html#downloadDirectory(software.amazon.awssdk.transfer.s3.model.DownloadDirectoryRequest)) 方法，传入。[DownloadDirectoryRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/DownloadDirectoryRequest.html)

该[DirectoryDownload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/DirectoryDownload.html)对象表示下载过程，该过程会在请求完成[CompletedDirectoryDownload](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/transfer/s3/model/CompletedDirectoryDownload.html)时生成。`CompleteDirectoryDownload` 对象包含有关传输结果的信息，包括哪些文件传输失败。

```
    public Integer downloadObjectsToDirectory(S3TransferManager transferManager,
            URI destinationPathURI, String bucketName) {
        DirectoryDownload directoryDownload = transferManager.downloadDirectory(DownloadDirectoryRequest.builder()
                .destination(Paths.get(destinationPathURI))
                .bucket(bucketName)
                .build());
        CompletedDirectoryDownload completedDirectoryDownload = directoryDownload.completionFuture().join();

        completedDirectoryDownload.failedTransfers()
                .forEach(fail -> logger.warn("Object [{}] failed to transfer", fail.toString()));
        return completedDirectoryDownload.failedTransfers().size();
    }
```

### 导入
<a name="transfer-manager-download_directory-import"></a>

```
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.services.s3.model.ObjectIdentifier;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedDirectoryDownload;
import software.amazon.awssdk.transfer.s3.model.DirectoryDownload;
import software.amazon.awssdk.transfer.s3.model.DownloadDirectoryRequest;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashSet;
import java.util.Set;
import java.util.UUID;
import java.util.stream.Collectors;
```

## 查看完整示例
<a name="transfer-manager-example-location"></a>

[GitHub 包含本页上所有示例的完整](https://github.com/awsdocs/aws-doc-sdk-examples/tree/d73001daea05266eaa9e074ccb71b9383832369a/javav2/example_code/s3/src/main/java/com/example/s3/transfermanager)代码。