/**
* 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.activemq.transport.mqtt;
import java.io.IOException;
import java.util.zip.DataFormatException;
import javax.jms.JMSException;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ActiveMQMessage;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageDispatch;
import org.fusesource.mqtt.client.QoS;
import org.fusesource.mqtt.codec.PUBLISH;
/**
* Keeps track of the MQTT client subscription so that acking is correctly done.
*/
public class MQTTSubscription {
private final MQTTProtocolConverter protocolConverter;
private final ConsumerInfo consumerInfo;
private final String topicName;
private final QoS qos;
public MQTTSubscription(MQTTProtocolConverter protocolConverter, String topicName, QoS qos, ConsumerInfo consumerInfo) {
this.protocolConverter = protocolConverter;
this.consumerInfo = consumerInfo;
this.qos = qos;
this.topicName = topicName;
}
/**
* Create a {@link MessageAck} that will acknowledge the given {@link MessageDispatch}.
*
* @param md
* the {@link MessageDispatch} to acknowledge.
*
* @return a new {@link MessageAck} command to acknowledge the message.
*/
public MessageAck createMessageAck(MessageDispatch md) {
return new MessageAck(md, MessageAck.INDIVIDUAL_ACK_TYPE, 1);
}
/**
* Creates a PUBLISH command that can be sent to a remote client from an
* incoming {@link ActiveMQMessage} instance.
*
* @param message
* the message to convert to a PUBLISH command.
*
* @return a new PUBLISH command that is populated from the {@link ActiveMQMessage}.
*
* @throws DataFormatException
* @throws IOException
* @throws JMSException
*/
public PUBLISH createPublish(ActiveMQMessage message) throws DataFormatException, IOException, JMSException {
PUBLISH publish = protocolConverter.convertMessage(message);
if (publish.qos().ordinal() > this.qos.ordinal()) {
publish.qos(this.qos);
}
switch (publish.qos()) {
case AT_LEAST_ONCE:
case EXACTLY_ONCE:
// set packet id, and optionally dup flag
protocolConverter.getPacketIdGenerator().setPacketId(protocolConverter.getClientId(), this, message, publish);
case AT_MOST_ONCE:
}
return publish;
}
/**
* Given a PUBLISH command determine if it will expect an ACK based on the
* QoS of the Publish command and the QoS of this subscription.
*
* @param publish
* The publish command to inspect.
*
* @return true if the client will expect an PUBACK for this PUBLISH.
*/
public boolean expectAck(PUBLISH publish) {
QoS publishQoS = publish.qos();
if (publishQoS.compareTo(this.qos) > 0){
publishQoS = this.qos;
}
return !publishQoS.equals(QoS.AT_MOST_ONCE);
}
/**
* @returns the original topic name value the client used when subscribing.
*/
public String getTopicName() {
return this.topicName;
}
/**
* The real {@link ActiveMQDestination} that this subscription is assigned.
*
* @return the real {@link ActiveMQDestination} assigned to this subscription.
*/
public ActiveMQDestination getDestination() {
return consumerInfo.getDestination();
}
/**
* Gets the {@link ConsumerInfo} that describes the subscription sent to ActiveMQ.
*
* @return the {@link ConsumerInfo} used to create this subscription.
*/
public ConsumerInfo getConsumerInfo() {
return consumerInfo;
}
/**
* @return the assigned QoS value for this subscription.
*/
public QoS getQoS() {
return qos;
}
@Override
public String toString() {
return "MQTT Sub: topic[" + topicName + "] -> [" + consumerInfo.getDestination() + "]";
}
}