/**
* 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.sqs;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import com.amazonaws.AmazonClientException;
import com.amazonaws.services.sqs.AmazonSQSClient;
import com.amazonaws.services.sqs.model.DeleteMessageRequest;
import com.amazonaws.services.sqs.model.Message;
import com.amazonaws.services.sqs.model.ReceiveMessageRequest;
import com.amazonaws.services.sqs.model.ReceiveMessageResult;
import org.apache.camel.BatchConsumer;
import org.apache.camel.Exchange;
import org.apache.camel.NoFactoryAvailableException;
import org.apache.camel.Processor;
import org.apache.camel.ShutdownRunningTask;
import org.apache.camel.impl.ScheduledPollConsumer;
import org.apache.camel.spi.ShutdownAware;
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 Queue Service
* <a href="http://aws.amazon.com/sqs/">AWS SQS</a>
*
*/
public class SqsConsumer extends ScheduledPollConsumer implements BatchConsumer, ShutdownAware {
private static final transient Logger LOG = LoggerFactory.getLogger(SqsConsumer.class);
private volatile ShutdownRunningTask shutdownRunningTask;
private volatile int pendingExchanges;
public SqsConsumer(SqsEndpoint endpoint, Processor processor) throws NoFactoryAvailableException {
super(endpoint, processor);
}
@Override
protected int poll() throws Exception {
// must reset for each poll
shutdownRunningTask = null;
pendingExchanges = 0;
ReceiveMessageRequest request = new ReceiveMessageRequest(getQueueUrl());
request.setMaxNumberOfMessages(getMaxMessagesPerPoll() > 0 ? getMaxMessagesPerPoll() : null);
request.setVisibilityTimeout(getConfiguration().getVisibilityTimeout() != null ? getConfiguration().getVisibilityTimeout() : null);
request.setAttributeNames(getConfiguration().getAttributeNames() != null ? getConfiguration().getAttributeNames() : null);
LOG.trace("Receiving messages with request [{}]...", request);
ReceiveMessageResult messageResult = getClient().receiveMessage(request);
LOG.trace("Received {} messages", messageResult.getMessages().size());
Queue<Exchange> exchanges = createExchanges(messageResult.getMessages());
return processBatch(CastUtils.cast(exchanges));
}
protected Queue<Exchange> createExchanges(List<Message> messages) {
LOG.trace("Received {} messages in this poll", messages.size());
Queue<Exchange> answer = new LinkedList<Exchange>();
for (Message message : messages) {
Exchange exchange = getEndpoint().createExchange(message);
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 "SqsConsumerOnCompletion";
}
});
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 receiptHandle = exchange.getIn().getHeader(SqsConstants.RECEIPT_HANDLE, String.class);
DeleteMessageRequest deleteRequest = new DeleteMessageRequest(getQueueUrl(), receiptHandle);
LOG.trace("Deleting message with receipt handle {}...", receiptHandle);
getClient().deleteMessage(deleteRequest);
LOG.trace("Message deleted");
}
} catch (AmazonClientException e) {
LOG.warn("Error occurred during deleting message", 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);
}
}
public boolean isBatchAllowed() {
// stop if we are not running
boolean answer = isRunAllowed();
if (!answer) {
return false;
}
if (shutdownRunningTask == null) {
// we are not shutting down so continue to run
return true;
}
// we are shutting down so only continue if we are configured to complete all tasks
return ShutdownRunningTask.CompleteAllTasks == shutdownRunningTask;
}
public boolean deferShutdown(ShutdownRunningTask shutdownRunningTask) {
// store a reference what to do in case when shutting down and we have pending messages
this.shutdownRunningTask = shutdownRunningTask;
// do not defer shutdown
return false;
}
public int getPendingExchangesSize() {
// only return the real pending size in case we are configured to complete all tasks
if (ShutdownRunningTask.CompleteAllTasks == shutdownRunningTask) {
return pendingExchanges;
} else {
return 0;
}
}
public void prepareShutdown() {
// noop
}
protected SqsConfiguration getConfiguration() {
return getEndpoint().getConfiguration();
}
protected AmazonSQSClient getClient() {
return getEndpoint().getClient();
}
protected String getQueueUrl() {
return getEndpoint().getQueueUrl();
}
@Override
public SqsEndpoint getEndpoint() {
return (SqsEndpoint) super.getEndpoint();
}
public void setMaxMessagesPerPoll(int maxMessagesPerPoll) {
getEndpoint().setMaxMessagesPerPoll(maxMessagesPerPoll);
}
public int getMaxMessagesPerPoll() {
return getEndpoint().getMaxMessagesPerPoll();
}
@Override
public String toString() {
return "SqsConsumer[" + URISupport.sanitizeUri(getEndpoint().getEndpointUri()) + "]";
}
}