@Override
public void configure(Context context) {
_ConnectionFactory = RabbitMQUtil.getFactory(context);
_QueueName = RabbitMQUtil.getQueueName(context);
_ExchangeName = RabbitMQUtil.getExchangeName(context);
_Topics = RabbitMQUtil.getTopics(context);
ensureConfigCompleteness(context);
}
private void resetConnection() {
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_EXCEPTION);
if (log.isWarnEnabled())
log.warn(this.getName() + " - Closing RabbitMQ connection and channel due to exception.");
RabbitMQUtil.close(_Connection, _Channel);
_Connection = null;
_Channel = null;
}
@Override
public PollableSource.Status process() throws EventDeliveryException {
if (null == _Connection) {
try {
if (log.isInfoEnabled())
log.info(
this.getName()
+ " - Opening connection to "
+ _ConnectionFactory.getHost()
+ ":"
+ _ConnectionFactory.getPort());
_Connection = _ConnectionFactory.newConnection();
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_NEW_CONNECTION);
_Channel = null;
} catch (Exception ex) {
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception while establishing connection.", ex);
resetConnection();
return Status.BACKOFF;
}
}
if (null == _Channel) {
try {
if (log.isInfoEnabled()) log.info(this.getName() + " - creating channel...");
_Channel = _Connection.createChannel();
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_NEW_CHANNEL);
if (log.isInfoEnabled())
log.info(
this.getName()
+ " - Connected to "
+ _ConnectionFactory.getHost()
+ ":"
+ _ConnectionFactory.getPort());
if (StringUtils.isNotEmpty(_ExchangeName)) {
try {
// declare an exchange
_Channel.exchangeDeclarePassive(_ExchangeName);
// only grab a default queuename if one is not specified in config
if (StringUtils.isEmpty(_QueueName)) {
_QueueName = _Channel.queueDeclare().getQueue();
}
// for each topic, bind to the key
if (null != _Topics) {
for (String topic : _Topics) {
_Channel.queueBind(_QueueName, _ExchangeName, topic);
}
}
} catch (Exception ex) {
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception while declaring exchange.", ex);
resetConnection();
return Status.BACKOFF;
}
}
} catch (Exception ex) {
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception while creating channel.", ex);
resetConnection();
return Status.BACKOFF;
}
}
GetResponse response;
try {
response = _Channel.basicGet(_QueueName, false);
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_GET);
} catch (Exception ex) {
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_EXCEPTION);
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception thrown while pulling from queue.", ex);
resetConnection();
return Status.BACKOFF;
}
if (null == response) {
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_GET_MISS);
return Status.BACKOFF;
}
try {
Map<String, String> properties = RabbitMQUtil.getHeaders(response.getProps());
Event event = new SimpleEvent();
event.setBody(response.getBody());
event.setHeaders(properties);
getChannelProcessor().processEvent(event);
} catch (Exception ex) {
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception thrown while processing event", ex);
return Status.BACKOFF;
}
try {
_Channel.basicAck(response.getEnvelope().getDeliveryTag(), false);
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_ACK);
} catch (Exception ex) {
_CounterGroup.incrementAndGet(RabbitMQConstants.COUNTER_EXCEPTION);
if (log.isErrorEnabled())
log.error(this.getName() + " - Exception thrown while sending ack to queue", ex);
resetConnection();
return Status.BACKOFF;
}
return Status.READY;
}
@Override
public synchronized void stop() {
RabbitMQUtil.close(_Connection, _Channel);
super.stop();
}