source: trunk/src/main/java/omq/server/InvocationThread.java

package omq.server;

import java.lang.reflect.InvocationTargetException;
import java.util.concurrent.BlockingQueue;

import omq.common.message.Request;
import omq.common.message.Response;
import omq.common.util.Serializer;
import omq.exception.OmqException;

import org.apache.log4j.Logger;

import com.rabbitmq.client.AMQP.BasicProperties;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.QueueingConsumer.Delivery;

/**
 * An invocationThread waits for requests an invokes them.
 * 
 * @author Sergi Toda <sergi.toda@estudiants.urv.cat>
 * 
 */
public class InvocationThread extends Thread {
        private static final Logger logger = Logger.getLogger(InvocationThread.class.getName());
        private RemoteObject obj;
        private transient Serializer serializer;
        private BlockingQueue<Delivery> deliveryQueue;
        private boolean killed = false;

        public InvocationThread(RemoteObject obj, BlockingQueue<Delivery> deliveryQueue, Serializer serializer) {
                this.obj = obj;
                this.deliveryQueue = deliveryQueue;
                this.serializer = serializer;
        }

        @Override
        public void run() {
                while (!killed) {
                        try {
                                // Get the delivery
                                Delivery delivery = deliveryQueue.take();

                                String serializerType = delivery.getProperties().getType();

                                // Deserialize the json
                                Request request = serializer.deserializeRequest(serializerType, delivery.getBody(), obj);
                                String methodName = request.getMethod();
                                String requestID = request.getId();

                                logger.debug("Object: " + obj.getRef() + ", method: " + methodName + " corrID: " + requestID + ", serializerType: " + serializerType);

                                // Invoke the method
                                Object result = null;
                                OmqException error = null;
                                try {
                                        result = obj.invokeMethod(request.getMethod(), request.getParams());
                                } catch (InvocationTargetException e) {
                                        Throwable throwable = e.getTargetException();
                                        logger.error("Object: " + obj.getRef() + " at method: " + methodName + ", corrID" + requestID, throwable);
                                        error = new OmqException(throwable.getClass().getCanonicalName(), throwable.getMessage());
                                } catch (NoSuchMethodException e) {
                                        logger.error("Object: " + obj.getRef() + " cannot find method: " + methodName);
                                        error = new OmqException(e.getClass().getCanonicalName(), e.getMessage());
                                }

                                // Reply if it's necessary
                                if (!request.isAsync()) {
                                        Response resp = new Response(request.getId(), obj.getRef(), result, error);

                                        Channel channel = obj.getChannel();

                                        BasicProperties props = delivery.getProperties();

                                        BasicProperties replyProps = new BasicProperties.Builder().appId(obj.getRef()).correlationId(props.getCorrelationId()).build();

                                        byte[] bytesResponse = serializer.serialize(serializerType, resp);
                                        channel.basicPublish("", props.getReplyTo(), replyProps, bytesResponse);
                                        logger.debug("Publish sync response -> Object: " + obj.getRef() + ", method: " + methodName + " corrID: " + requestID + " replyTo: "
                                                        + props.getReplyTo());
                                }

                        } catch (InterruptedException i) {
                                logger.error(i);
                                killed = true;
                        } catch (Exception e) {
                                logger.error("Object: " + obj.getRef(), e);
                        }

                }
        }

        public RemoteObject getObj() {
                return obj;
        }

        public void setObj(RemoteObject obj) {
                this.obj = obj;
        }

        public BlockingQueue<Delivery> getDeliveryQueue() {
                return deliveryQueue;
        }

        public void setDeliveryQueue(BlockingQueue<Delivery> deliveryQueue) {
                this.deliveryQueue = deliveryQueue;
        }
}