RabbitMQ.java

package com.urbanairship.octobot;

import org.apache.log4j.Logger;
import com.rabbitmq.client.Channel;
import java.io.IOException;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;


// This class handles all interfacing with AMQP / RabbitMQ in Octobot.
// It provides basic connection management and returns task channels
// for placing messages into a remote queue.

public class RabbitMQ {

    private static final Logger logger = Logger.getLogger("RabbitMQ");
    public static final ConnectionFactory factory = new ConnectionFactory();

    public RabbitMQ(Queue queue) {
        factory.setHost(queue.host);
        factory.setPort(queue.port);
        factory.setUsername(queue.username);
        factory.setPassword(queue.password);
        factory.setVirtualHost(queue.vhost);
    }

    // Returns a new connection to an AMQP queue.
    public Connection getConnection() throws IOException {
        return factory.newConnection();
    }

    // Returns a live channel for publishing messages.
    public Channel getTaskChannel() {
        Channel taskChannel = null;

        int attempts = 0;
        while (true) {
            attempts++;
            logger.info("Attempting to connect to queue: attempt " + attempts);
            try {
                Connection connection = getConnection();
                taskChannel = connection.createChannel();
                break;
            } catch (IOException e) {
                logger.error("Error creating AMQP channel, retrying in 5 sec", e);
                try { Thread.sleep(1000 * 5); }
                catch (InterruptedException ex) { }
            }
        }
        return taskChannel;
    }
}