private NotificationListener createListener()

in src/main/java/com/uber/rss/common/MemoryMonitor.java [52:92]
38 lines of code
5 McCabe index (conditional complexity)

    private NotificationListener createListener(int lowMemoryPercentage, LowMemoryListener lowMemoryListener) {
        return new NotificationListener() {
            @Override
            public void handleNotification(Notification notification, Object handback) {
                if (notification.getType().equals(
                        GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
                    GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo
                            .from((CompositeData)notification.getUserData());
                    String gcAction = info.getGcAction();
                    GcInfo gcInfo = info.getGcInfo();
                    logger.info(String.format("GcAction: %s, start: %s, duration: %s", 
                            gcAction, gcInfo.getStartTime(), gcInfo.getDuration()));
                    gcTime.update(gcInfo.getDuration());
                    if (gcAction.toLowerCase().contains("major")) {
                        majorGCTime.update(gcInfo.getDuration());
                        // only check when major (full) GC
                        MemoryMXBean memoryMXBean;
                        try {
                            memoryMXBean = ManagementFactory.getMemoryMXBean();
                        } catch (Throwable ex) {
                            M3Stats.addException(ex, M3Stats.TAG_VALUE_MEMORY_MONITOR);
                            throw new RssException("Failed to run getMemoryMXBean", ex);
                        }

                        MemoryUsage memoryUsage = memoryMXBean.getHeapMemoryUsage();
                        long usedPercentage = memoryUsage.getUsed() * 100 / memoryUsage.getMax();
                        logger.info(String.format("Heap memory, used: %s (%s%%), max: %s, committed: %s", 
                                memoryUsage.getUsed(), usedPercentage, memoryUsage.getMax(), memoryUsage.getCommitted()));
                        heapMemoryPercentage.update(usedPercentage);
                        
                        if (usedPercentage > lowMemoryPercentage) {
                            logger.info(String.format(
                                    "Triggering low memory listener due to used memory percentage %s larger than threshold %s",
                                    usedPercentage, lowMemoryPercentage));
                            lowMemoryListener.run();
                        }
                    }
                }
            }
        };
    }