AWS Code Sample
Catalog

ListKeys.java

ListKeys.java demonstrates how to retrieve and iterate through a list of the keys contained in an S3 bucket.

/** * Copyright 2018-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * This file is licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. A copy of * the License is located at * * http://aws.amazon.com/apache2.0/ * * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR * CONDITIONS OF ANY KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. */ import java.io.IOException; import com.amazonaws.AmazonServiceException; import com.amazonaws.SdkClientException; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3ClientBuilder; import com.amazonaws.services.s3.model.ListObjectsV2Request; import com.amazonaws.services.s3.model.ListObjectsV2Result; import com.amazonaws.services.s3.model.S3ObjectSummary; public class ListKeys { public static void main(String[] args) throws IOException { String clientRegion = "*** Client region ***"; String bucketName = "*** Bucket name ***"; try { AmazonS3 s3Client = AmazonS3ClientBuilder.standard() .withCredentials(new ProfileCredentialsProvider()) .withRegion(clientRegion) .build(); System.out.println("Listing objects"); // maxKeys is set to 2 to demonstrate the use of // ListObjectsV2Result.getNextContinuationToken() ListObjectsV2Request req = new ListObjectsV2Request().withBucketName(bucketName).withMaxKeys(2); ListObjectsV2Result result; do { result = s3Client.listObjectsV2(req); for (S3ObjectSummary objectSummary : result.getObjectSummaries()) { System.out.printf(" - %s (size: %d)\n", objectSummary.getKey(), objectSummary.getSize()); } // If there are more than maxKeys keys in the bucket, get a continuation token // and list the next objects. String token = result.getNextContinuationToken(); System.out.println("Next Continuation Token: " + token); req.setContinuationToken(token); } while (result.isTruncated()); } catch(AmazonServiceException e) { // The call was transmitted successfully, but Amazon S3 couldn't process // it, so it returned an error response. e.printStackTrace(); } catch(SdkClientException e) { // Amazon S3 couldn't be contacted for a response, or the client // couldn't parse the response from Amazon S3. e.printStackTrace(); } } }

Sample Details

Service: s3

Last tested: 2019-01-28

Author: AWS

Type: full-example

On this page: