Example usage for com.amazonaws.services.s3.model ListObjectsV2Result getKeyCount

Introduction

In this page you can find the example usage for com.amazonaws.services.s3.model ListObjectsV2Result getKeyCount.

Prototype

public int getKeyCount() 

Source Link

Document

Gets the number of keys returned with this response.

Usage

From source file:io.druid.storage.s3.S3DataSegmentMover.java

License:Apache License

/**
 * Copies an object and after that checks that the object is present at the target location, via a separate API call.
 * If it is not, an exception is thrown, and the object is not deleted at the old location. This "paranoic" check
 * is added after it was observed that S3 may report a successful move, and the object is not found at the target
 * location.//from ww  w .jav a2s .co m
 */
private void selfCheckingMove(String s3Bucket, String targetS3Bucket, String s3Path, String targetS3Path,
        String copyMsg) throws IOException, SegmentLoadingException {
    if (s3Bucket.equals(targetS3Bucket) && s3Path.equals(targetS3Path)) {
        log.info("No need to move file[s3://%s/%s] onto itself", s3Bucket, s3Path);
        return;
    }
    if (s3Client.doesObjectExist(s3Bucket, s3Path)) {
        final ListObjectsV2Result listResult = s3Client.listObjectsV2(
                new ListObjectsV2Request().withBucketName(s3Bucket).withPrefix(s3Path).withMaxKeys(1));
        if (listResult.getKeyCount() == 0) {
            // should never happen
            throw new ISE("Unable to list object [s3://%s/%s]", s3Bucket, s3Path);
        }
        final S3ObjectSummary objectSummary = listResult.getObjectSummaries().get(0);
        if (objectSummary.getStorageClass() != null
                && StorageClass.fromValue(StringUtils.toUpperCase(objectSummary.getStorageClass()))
                        .equals(StorageClass.Glacier)) {
            throw new AmazonServiceException(StringUtils.format(
                    "Cannot move file[s3://%s/%s] of storage class glacier, skipping.", s3Bucket, s3Path));
        } else {
            log.info("Moving file %s", copyMsg);
            final CopyObjectRequest copyRequest = new CopyObjectRequest(s3Bucket, s3Path, targetS3Bucket,
                    targetS3Path);
            if (!config.getDisableAcl()) {
                copyRequest
                        .setAccessControlList(S3Utils.grantFullControlToBucketOwner(s3Client, targetS3Bucket));
            }
            s3Client.copyObject(copyRequest);
            if (!s3Client.doesObjectExist(targetS3Bucket, targetS3Path)) {
                throw new IOE(
                        "After copy was reported as successful the file doesn't exist in the target location [%s]",
                        copyMsg);
            }
            deleteWithRetriesSilent(s3Bucket, s3Path);
            log.debug("Finished moving file %s", copyMsg);
        }
    } else {
        // ensure object exists in target location
        if (s3Client.doesObjectExist(targetS3Bucket, targetS3Path)) {
            log.info("Not moving file [s3://%s/%s], already present in target location [s3://%s/%s]", s3Bucket,
                    s3Path, targetS3Bucket, targetS3Path);
        } else {
            throw new SegmentLoadingException(
                    "Unable to move file %s, not present in either source or target location", copyMsg);
        }
    }
}

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From source file:io.druid.storage.s3.S3Utils.java

License:Apache License

/**
 * Gets a single {@link S3ObjectSummary} from s3. Since this method might return a wrong object if there are multiple
 * objects that match the given key, this method should be used only when it's guaranteed that the given key is unique
 * in the given bucket.//  ww w.j a  v a 2 s .  c o  m
 *
 * @param s3Client s3 client
 * @param bucket   s3 bucket
 * @param key      unique key for the object to be retrieved
 */
public static S3ObjectSummary getSingleObjectSummary(AmazonS3 s3Client, String bucket, String key) {
    final ListObjectsV2Request request = new ListObjectsV2Request().withBucketName(bucket).withPrefix(key)
            .withMaxKeys(1);
    final ListObjectsV2Result result = s3Client.listObjectsV2(request);

    if (result.getKeyCount() == 0) {
        throw new ISE("Cannot find object for bucket[%s] and key[%s]", bucket, key);
    }
    final S3ObjectSummary objectSummary = result.getObjectSummaries().get(0);
    if (!objectSummary.getBucketName().equals(bucket) || !objectSummary.getKey().equals(key)) {
        throw new ISE("Wrong object[%s] for bucket[%s] and key[%s]", objectSummary, bucket, key);
    }

    return objectSummary;
}

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