java - 列出 aws 存储桶中的对象

Question

我试图打印存储桶中的所有对象，但出现错误。

Exception in thread "main" com.amazonaws.services.s3.model.AmazonS3Exception: Status Code: 301, AWS Service: Amazon S3, AWS Request ID: 758A7CBF1A29FD74, AWS Error Code: PermanentRedirect, AWS Error Message: The bucket you are attempting to access must be addressed using the specified endpoint. Please send all future requests to this endpoint., S3

目前我只有以下代码:

public class S3Download {

    /**
     * @param args
     */
    public static void main(String[] args) {
        AmazonS3 s3 = new AmazonS3Client(new ClasspathPropertiesFileCredentialsProvider());
        Region usWest2 = Region.getRegion(Regions.US_WEST_2);
        s3.setRegion(usWest2);
        String bucketName = "apireleasecandidate1";

        ListObjectsRequest listObjectRequest = new ListObjectsRequest().withBucketName(bucketName);
        ObjectListing objectListing;

        do{
            objectListing = s3.listObjects(listObjectRequest);
            for(S3ObjectSummary objectSummary : objectListing.getObjectSummaries()){
                System.out.println(" - " + objectSummary.getKey() + " " + "(size = " +
            objectSummary.getSize() + ")");
            }
            listObjectRequest.setMarker(objectListing.getNextMarker());
        }while(objectListing.isTruncated());
    }

}

我找到了 this solution在亚马逊的网站上。

有人知道我错过了什么吗？

Answer 1

对于 Scala 开发人员，这里是使用官方 AWS SDK for Java 对 AmazonS3 存储桶的内容执行完整扫描和映射 的递归函数

import com.amazonaws.services.s3.AmazonS3Client
import com.amazonaws.services.s3.model.{S3ObjectSummary, ObjectListing, GetObjectRequest}
import scala.collection.JavaConversions.{collectionAsScalaIterable => asScala}

def map[T](s3: AmazonS3Client, bucket: String, prefix: String)(f: (S3ObjectSummary) => T) = {

  def scan(acc:List[T], listing:ObjectListing): List[T] = {
    val summaries = asScala[S3ObjectSummary](listing.getObjectSummaries())
    val mapped = (for (summary <- summaries) yield f(summary)).toList

    if (!listing.isTruncated) mapped.toList
    else scan(acc ::: mapped, s3.listNextBatchOfObjects(listing))
  }

  scan(List(), s3.listObjects(bucket, prefix))
}

要调用上述柯里化(Currying)的map()函数，只需传递已经构建(并正确初始化)的AmazonS3Client对象(引用官方AWS SDK for Java API Reference)，存储桶名称和前缀名称第一个参数列表。还要传递要应用的函数 f()，以映射第二个参数列表中的每个对象摘要。

例如

map(s3, bucket, prefix)(s => println(s))

将打印所有文件

val tuple = map(s3, bucket, prefix)(s => (s.getKey, s.getOwner, s.getSize))

将返回该桶/前缀中的(key, owner, size)元组的完整列表

val totalSize = map(s3, "bucket", "prefix")(s => s.getSize).sum

将返回其内容的总大小(注意在表达式末尾应用的附加 sum() 折叠函数 ;-)

您可以将 map() 与许多其他函数结合使用，就像您通常通过 Monads in Functional Programming 接近的那样