/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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.
*/
package org.apache.camel.component.aws.s3;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import com.amazonaws.AmazonClientException;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.ListObjectsRequest;
import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectSummary;
import org.apache.camel.Exchange;
import org.apache.camel.NoFactoryAvailableException;
import org.apache.camel.Processor;
import org.apache.camel.impl.ScheduledBatchPollingConsumer;
import org.apache.camel.spi.Synchronization;
import org.apache.camel.util.CastUtils;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.URISupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A Consumer of messages from the Amazon Web Service Simple Storage Service
* <a href="http://aws.amazon.com/s3/">AWS S3</a>
*
*/
public class S3Consumer extends ScheduledBatchPollingConsumer {
private static final transient Logger LOG = LoggerFactory.getLogger(S3Consumer.class);
public S3Consumer(S3Endpoint endpoint, Processor processor) throws NoFactoryAvailableException {
super(endpoint, processor);
}
@Override
protected int poll() throws Exception {
// must reset for each poll
shutdownRunningTask = null;
pendingExchanges = 0;
String bucketName = getConfiguration().getBucketName();
LOG.trace("Quering objects in bucket [{}]...", bucketName);
ListObjectsRequest listObjectsRequest = new ListObjectsRequest();
listObjectsRequest.setBucketName(bucketName);
listObjectsRequest.setPrefix(getConfiguration().getPrefix());
listObjectsRequest.setMaxKeys(maxMessagesPerPoll);
ObjectListing listObjects = getAmazonS3Client().listObjects(listObjectsRequest);
LOG.trace("Found {} objects in bucket [{}]...", listObjects.getObjectSummaries().size(), bucketName);
Queue<Exchange> exchanges = createExchanges(listObjects.getObjectSummaries());
return processBatch(CastUtils.cast(exchanges));
}
protected Queue<Exchange> createExchanges(List<S3ObjectSummary> s3ObjectSummaries) {
LOG.trace("Received {} messages in this poll", s3ObjectSummaries.size());
Queue<Exchange> answer = new LinkedList<Exchange>();
for (S3ObjectSummary s3ObjectSummary : s3ObjectSummaries) {
S3Object s3Object = getAmazonS3Client().getObject(s3ObjectSummary.getBucketName(), s3ObjectSummary.getKey());
Exchange exchange = getEndpoint().createExchange(s3Object);
answer.add(exchange);
}
return answer;
}
public int processBatch(Queue<Object> exchanges) throws Exception {
int total = exchanges.size();
for (int index = 0; index < total && isBatchAllowed(); index++) {
// only loop if we are started (allowed to run)
Exchange exchange = ObjectHelper.cast(Exchange.class, exchanges.poll());
// add current index and total as properties
exchange.setProperty(Exchange.BATCH_INDEX, index);
exchange.setProperty(Exchange.BATCH_SIZE, total);
exchange.setProperty(Exchange.BATCH_COMPLETE, index == total - 1);
// update pending number of exchanges
pendingExchanges = total - index - 1;
// add on completion to handle after work when the exchange is done
exchange.addOnCompletion(new Synchronization() {
public void onComplete(Exchange exchange) {
processCommit(exchange);
}
public void onFailure(Exchange exchange) {
processRollback(exchange);
}
@Override
public String toString() {
return "S3ConsumerOnCompletion";
}
});
LOG.trace("Processing exchange [{}]...", exchange);
getProcessor().process(exchange);
}
return total;
}
/**
* Strategy to delete the message after being processed.
*
* @param exchange the exchange
*/
protected void processCommit(Exchange exchange) {
try {
if (getConfiguration().isDeleteAfterRead()) {
String bucketName = exchange.getIn().getHeader(S3Constants.BUCKET_NAME, String.class);
String key = exchange.getIn().getHeader(S3Constants.KEY, String.class);
LOG.trace("Deleting object from bucket {} with key {}...", bucketName, key);
getAmazonS3Client().deleteObject(bucketName, key);
LOG.trace("Object deleted");
}
} catch (AmazonClientException e) {
LOG.warn("Error occurred during deleting object", e);
exchange.setException(e);
}
}
/**
* Strategy when processing the exchange failed.
*
* @param exchange the exchange
*/
protected void processRollback(Exchange exchange) {
Exception cause = exchange.getException();
if (cause != null) {
LOG.warn("Exchange failed, so rolling back message status: " + exchange, cause);
} else {
LOG.warn("Exchange failed, so rolling back message status: {}", exchange);
}
}
protected S3Configuration getConfiguration() {
return getEndpoint().getConfiguration();
}
protected AmazonS3Client getAmazonS3Client() {
return getEndpoint().getS3Client();
}
@Override
public S3Endpoint getEndpoint() {
return (S3Endpoint) super.getEndpoint();
}
@Override
public String toString() {
return "S3Consumer[" + URISupport.sanitizeUri(getEndpoint().getEndpointUri()) + "]";
}
}