content: package rabbit_java.rpc;
  
  import com.rabbitmq.client.ConnectionFactory;
  import com.rabbitmq.client.Connection;
  import com.rabbitmq.client.Channel;
  import com.rabbitmq.client.QueueingConsumer;
  
  import utils.RabbitMQConnectionFactory;
  
  import com.rabbitmq.client.AMQP.BasicProperties;
  
  public class RPCServer {
  
  	private static final String RPC_QUEUE_NAME = "rpc_queue";
  
  	private static int fib(int n) {
  		if (n == 0)
  			return 0;
  		if (n == 1)
  			return 1;
  		return fib(n - 1) + fib(n - 2);
  	}
  
  	public static void main(String[] argv) {
  		Connection connection = null;
  		Channel channel = null;
  		try {
  			ConnectionFactory factory = RabbitMQConnectionFactory.getFactory();
  
  			connection = factory.newConnection();
  			channel = connection.createChannel();
  
  			channel.queueDeclare(RPC_QUEUE_NAME, false, false, false, null);
  
  			channel.basicQos(1);
  
  			QueueingConsumer consumer = new QueueingConsumer(channel);
  			channel.basicConsume(RPC_QUEUE_NAME, false, consumer);
  
  			System.out.println(" [x] Awaiting RPC requests");
  
  			while (true) {
  				String response = null;
  
  				QueueingConsumer.Delivery delivery = consumer.nextDelivery();
  
  				BasicProperties props = delivery.getProperties();
  				BasicProperties replyProps = new BasicProperties.Builder().correlationId(props.getCorrelationId())
  						.build();
  
  				try {
  					String message = new String(delivery.getBody(), "UTF-8");
  					int n = Integer.parseInt(message);
  
  					System.out.println(" [.] fib(" + message + ")");
  					response = "" + fib(n);
  				} catch (Exception e) {
  					System.out.println(" [.] " + e.toString());
  					response = "";
  				} finally {
  					channel.basicPublish("", props.getReplyTo(), replyProps, response.getBytes("UTF-8"));
  
  					channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
  				}
  			}
  		} catch (Exception e) {
  			e.printStackTrace();
  		} finally {
  			if (connection != null) {
  				try {
  					connection.close();
  				} catch (Exception ignore) {
  				}
  			}
  		}
  	}
  }
  