ss.udapi.sdk.services.RabbitMqConsumer.java Source code

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Here is the source code for ss.udapi.sdk.services.RabbitMqConsumer.java

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//Copyright 2014 Spin Services Limited

//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 ss.udapi.sdk.services;

import ss.udapi.sdk.ResourceImpl;

import org.apache.log4j.Logger;

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.rabbitmq.client.ShutdownSignalException;

/* 
 * A listener providing call back methods which RabbitMQ uses to notify the SDK of an event.  The only ones we care about are:
 * 1) Message received.
 * 2) Connection lost.
 */
public class RabbitMqConsumer extends DefaultConsumer {
    private static Logger logger = Logger.getLogger(RabbitMqConsumer.class);
    private static boolean connectShutDownLogged = false;
    private EchoResourceMap echoMap = EchoResourceMap.getEchoMap();

    public RabbitMqConsumer(Channel channel) {
        super(channel);

    }

    // Message received from MQ
    @Override
    public void handleDelivery(String cTag, Envelope envelope, AMQP.BasicProperties properties,
            byte[] bodyByteArray) {

        // we're running and receiving so the connection hasn't been broken or
        // has been restored
        connectShutDownLogged = false;

        // Get the message header
        String body = new String(bodyByteArray);
        String msgHead = body.substring(0, 64);

        /*
         * If it's not an echo assign the work to a the queue's resource
         * implementation (fixture handler). The resource is retrieved from
         * CtagResourceMap which is maintained by MQListener (as it
         * creates/destroys queue listeners).
         */
        if (msgHead.equals("{\"Relation\":\"http://api.sportingsolutions.com/rels/stream/echo\",") != true) {

            WorkQueue myQueue = WorkQueue.getWorkQueue();
            if (myQueue.addTask(body))
                logger.debug("Consumer: " + cTag + " received non echo message: " + msgHead);
            else
                logger.warn("Error on adding a non echo message on consumer: " + cTag);
        }

        // We successfully got an echo response or some work from a queue, so
        // the queue must be OK.
        echoMap.resetEchoCount(CtagResourceMap.getResource(cTag));

    }

    /*
     * The queue has been disconnected. This was requested by us when the number
     * of echo retries was exceeded as managed by EchoSender or as a result of
     * the client code requesting ResourceImpl.stopStreaming(), a likely action
     * once a fixture has ended. Here we tidy up some maps which are no longer
     * needed (as the fixture/resource are no longer required). The client code
     * can re-instantiate the resource and new mapping will be created.
     */
    @Override
    public void handleCancelOk(String cTag) {

        logger.debug("Consumer: " + cTag + " disconnected");
        String resourceId = CtagResourceMap.getResource(cTag);
        ResourceImpl resource = (ResourceImpl) ResourceWorkerMap.getResourceImpl(resourceId);
        resource.mqDisconnectEvent();
        MQListener.removeMapping(cTag);
    }

    /*
     * The queue has been disconnected. But this time it was a result of a
     * failure on MQ (unlikely but we should allow for it). Here we tidy up some
     * maps which are no longer needed (as the fixture/resource are no longer
     * required). The client code can re-instantiate the resource and new
     * mapping will be created.
     */
    @Override
    public void handleCancel(String cTag) {
        logger.debug("Consumer: " + cTag + " disconnected");
        String resourceId = CtagResourceMap.getResource(cTag);
        ResourceImpl resource = (ResourceImpl) ResourceWorkerMap.getResourceImpl(resourceId);
        resource.mqDisconnectEvent();
        MQListener.removeMapping(cTag);
    }

    /*
     * The channel or connection has been shutdown. Log the event.
     */
    @Override
    public void handleShutdownSignal(String cTag, ShutdownSignalException signal) {

        if (connectShutDownLogged == false) {
            connectShutDownLogged = true; // so we don't end up logging it for
            // each cTag

            String hardError = "";
            String applInit = "";
            String reason = "";

            if (signal.isHardError()) {
                hardError = "connection";
            } else {
                hardError = "channel";
            }

            if (signal.isInitiatedByApplication()) {
                applInit = "application";
            } else {
                applInit = "broker";
            }

            reason = signal.getReason().toString();
            logger.error("Connectivity to MQ has failed.  It was caused by " + applInit + " at the " + hardError
                    + " level.  Reason received " + reason);
        }
        String resourceId = CtagResourceMap.getResource(cTag);
        ResourceImpl resource = (ResourceImpl) ResourceWorkerMap.getResourceImpl(resourceId);
        resource.mqDisconnectEvent();
        MQListener.removeMapping(cTag);
    }
}