如何下载S3存储桶上的整个文件夹？

Question

我已经使用Java SDK并尝试使用GetObjectRequest类下载Folder，但是有可能下载我的文件夹，包括其subFolder和所有要下载的文件吗？

Answer 1

您可以使用TransferManager类中的downloadDirectory方法：

TransferManager transferManager = new TransferManager(new DefaultAWSCredentialsProviderChain());
File dir = new File("destDir");

MultipleFileDownload download =  transferManager.downloadDirectory("myBucket", "myKey", dir);
download.waitForCompletion();

正如文档中所写，此方法：

将给定目标目录的给定keyPrefix指定的虚拟目录中的所有对象下载。 所有虚拟子目录将递归下载。

Answer 2

您必须调用ListBucket API来获取文件列表，然后使用GetObject单独下载每个文件

Answer 3

是的，使用TransferManager.downloadFolder :)

Answer 4

这是下载整个存储桶（经过一些测试）的代码：

import com.amazonaws.AmazonServiceException;
import aws.example.s3.XferMgrProgress;
import com.amazonaws.services.s3.transfer.TransferManager;
import com.amazonaws.services.s3.transfer.TransferManagerBuilder;
import com.amazonaws.services.s3.transfer.MultipleFileDownload;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import java.io.*;
import com.amazonaws.auth.PropertiesFileCredentialsProvider;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.AmazonClientException;
public class S3DownloadApp {

    public static void main(String [] args){
        AWSCredentials credentials = null;
        try {
            credentials = new PropertiesFileCredentialsProvider("keys.props").getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException(
                    "Cannot load the credentials from the credential profiles file. " , e);
        }

        TransferManager xfer_mgr = TransferManagerBuilder.standard().withS3Client(AmazonS3ClientBuilder.standard().withCredentials(new AWSStaticCredentialsProvider(credentials)).withRegion("us-west-2").build()).build();//TransferManagerBuilder.standard().build();

        try {
            MultipleFileDownload xfer = xfer_mgr.downloadDirectory(
                    "bucketName", null, new File("/Users/admin/Desktop/downloadFolder"));
            XferMgrProgress.showTransferProgress(xfer);
            XferMgrProgress.waitForCompletion(xfer);
        } catch (AmazonServiceException e) {
            System.err.println(e.getErrorMessage());
            System.exit(1);
        }
    }
}