MakingRequests.java

// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-s3-developer-guide/blob/master/LICENSE-SAMPLECODE.)

import java.io.IOException;
import java.util.List;

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.ListObjectsRequest;
import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.S3ObjectSummary;

public class MakingRequests {

    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();
    
            // Get a list of objects in the bucket, two at a time, and 
            // print the name and size of each object.
            ListObjectsRequest listRequest = new ListObjectsRequest().withBucketName(bucketName).withMaxKeys(2);
            ObjectListing objects = s3Client.listObjects(listRequest);
            while(true) {
                List<S3ObjectSummary> summaries = objects.getObjectSummaries();
                for(S3ObjectSummary summary : summaries) {
                    System.out.printf("Object \"%s\" retrieved with size %d\n", summary.getKey(), summary.getSize());
                }
                if(objects.isTruncated()) {
                    objects = s3Client.listNextBatchOfObjects(objects);
                }
                else {
                    break;
                }
            }
        }
        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();
        }
    }
}