Check if a bucket exists

You can use the following doesBucketExists method as a replacement for the the SDK for Java V1 AmazonS3Client#doesBucketExistV2(String) method.

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.awscore.exception.AwsServiceException;
import software.amazon.awssdk.http.HttpStatusCode;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.utils.Validate;

public class DoesBucketExist {
    private static final Logger logger = LoggerFactory.getLogger(DoesBucketExist.class);

    public static void main(String[] args) {
        DoesBucketExist doesBucketExist = new DoesBucketExist();

        final S3Client s3SyncClient = S3Client.builder().build();
        final String bucketName = "amzn-s3-demo-bucket"; // Change to the bucket name that you want to check.

        boolean exists = doesBucketExist.doesBucketExist(bucketName, s3SyncClient);
        logger.info("Bucket exists: {}", exists);
    }

    /**
     * Checks if the specified bucket exists. Amazon S3 buckets are named in a global namespace; use this method to
     * determine if a specified bucket name already exists, and therefore can't be used to create a new bucket.
     * <p>
     * Internally this method uses the <a
     * href="https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/s3/S3Client.html#getBucketAcl(java.util.function.Consumer)">S3Client.getBucketAcl(String)</a>
     * operation to determine whether the bucket exists.
     * <p>
     * This method is equivalent to the AWS SDK for Java V1's <a
     * href="https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Client.html#doesBucketExistV2-java.lang.String-">AmazonS3Client#doesBucketExistV2(String)</a>.
     *
     * @param bucketName   The name of the bucket to check.
     * @param s3SyncClient An <code>S3Client</code> instance. The method checks for the bucket in the AWS Region
     *                     configured on the instance.
     * @return The value true if the specified bucket exists in Amazon S3; the value false if there is no bucket in
     *         Amazon S3 with that name.
     */
    public boolean doesBucketExist(String bucketName, S3Client s3SyncClient) {
        try {
            Validate.notEmpty(bucketName, "The bucket name must not be null or an empty string.", "");
            s3SyncClient.getBucketAcl(r -> r.bucket(bucketName));
            return true;
        } catch (AwsServiceException ase) {
            // A redirect error or an AccessDenied exception means the bucket exists but it's not in this region
            // or we don't have permissions to it.
            if ((ase.statusCode() == HttpStatusCode.MOVED_PERMANENTLY) || "AccessDenied".equals(ase.awsErrorDetails().errorCode())) {
                return true;
            }
            if (ase.statusCode() == HttpStatusCode.NOT_FOUND) {
                return false;
            }
            throw ase;
        }
    }
}