/**
* Reads next key from S3
*
* @return {@link S3ObjectSummary} of the key or <code>null</code> if there are no more keys to
* read
*/
public S3ObjectSummary getNextKey() {
if (objectListing == null) {
LOG.debug("Listing objects");
objectListing = s3Client.listObjects(listObjectsRequest);
}
// we have more elements in list
if (currentPosition < objectListing.getObjectSummaries().size()) {
currentObject = objectListing.getObjectSummaries().get(currentPosition++);
} else if (objectListing.isTruncated()) {
LOG.debug("Current batch reached its end. Fetching next page.");
// when we're at the end, check if there's more data to read
listObjectsRequest.setMarker(objectListing.getNextMarker());
LOG.debug("New marker is set to {}", listObjectsRequest.getMarker());
objectListing = s3Client.listObjects(listObjectsRequest);
currentPosition = 0;
if (currentPosition < objectListing.getObjectSummaries().size()) {
currentObject = objectListing.getObjectSummaries().get(currentPosition++);
} else {
LOG.debug("No more objects to read");
currentObject = null;
}
} else {
currentObject = null;
}
return currentObject;
}
@Override
public boolean matches(final Object arg) {
boolean result = false;
if (arg instanceof ListObjectsRequest) {
final ListObjectsRequest obj = (ListObjectsRequest) arg;
result = true;
if (!this.bucket.equals(obj.getBucketName())) {
result = false;
}
if (!this.prefix.equals(obj.getPrefix())) {
result = false;
}
if (this.marker == null && obj.getMarker() != null) {
result = false;
}
if (this.marker != null && !this.marker.equals(obj.getMarker())) {
result = false;
}
}
return result;
}