code: protected ConnectionFactory retrieveConnectionFactory(String name) throws JMSException {
          if (name == null && defaultConnectionFactory != null) {
              return defaultConnectionFactory; // injected
          }
          else {
              try {
                  // autowiring did not occur
                  return (ConnectionFactory)SpringAppContext.getInstance().getBean(name);
              }
              catch (Exception ex) {
                  logger.severeException(ex.getMessage(), ex);
                  throw new JMSException("JMS ConnectionFactory not found: " + name);
              }
          }
      }
docs: Pooling and remote queues are configured via Spring in broker config XML.