com.nesscomputing.jms.AbstractConsumer Maven / Gradle / Ivy
/**
* Copyright (C) 2012 Ness Computing, Inc.
*
* Licensed 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 com.nesscomputing.jms;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicReference;
import javax.annotation.Nonnull;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
/**
* A general runnable that will keep the connection to a queue or topic alive and dispatch messages
* received to an instance that implements {@link ConsumerCallback}.
*/
public abstract class AbstractConsumer extends AbstractJmsRunnable
{
private AtomicReference consumerHolder = new AtomicReference();
private final ConsumerCallback messageCallback;
private final long tickTimeout;
protected AbstractConsumer(@Nonnull final ConnectionFactory connectionFactory,
@Nonnull final JmsConfig jmsConfig,
@Nonnull final String topic,
@Nonnull final ConsumerCallback messageCallback)
{
super(connectionFactory, jmsConfig, topic);
this.messageCallback = messageCallback;
this.tickTimeout = getConfig().getTickTimeout().getMillis();
}
@Override
protected void sessionDisconnect()
{
final MessageConsumer consumer = consumerHolder.getAndSet(null);
JmsUtils.closeQuietly(consumer);
super.sessionDisconnect();
}
@Override
protected boolean process() throws JMSException, IOException
{
sessionConnect();
final MessageConsumer consumer = consumerHolder.get();
final Message message;
if (consumer != null) {
message = consumer.receive(tickTimeout);
}
else {
LOG.warn("Session connected but no consumer available!");
message = null;
try {
Thread.sleep(tickTimeout);
}
catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}
}
if (message == null) {
LOG.trace("Tick...");
}
return messageCallback.withMessage(message);
}
protected void setConsumer(final MessageConsumer consumer)
{
this.consumerHolder.set(consumer);
}
}
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