private static void checkGarbageCollectionNotificationInfoContent(
      GarbageCollectionNotificationInfo notif) throws Exception {
    System.out.println("GC notification for " + notif.getGcName());
    System.out.print("Action: " + notif.getGcAction());
    System.out.println(" Cause: " + notif.getGcCause());
    GcInfo info = notif.getGcInfo();
    System.out.print("GC Info #" + info.getId());
    System.out.print(" start:" + info.getStartTime());
    System.out.print(" end:" + info.getEndTime());
    System.out.println(" (" + info.getDuration() + "ms)");
    Map<String, MemoryUsage> usage = info.getMemoryUsageBeforeGc();

    List<String> pnames = new ArrayList<String>();
    for (Map.Entry entry : usage.entrySet()) {
      String poolname = (String) entry.getKey();
      pnames.add(poolname);
      MemoryUsage busage = (MemoryUsage) entry.getValue();
      MemoryUsage ausage = (MemoryUsage) info.getMemoryUsageAfterGc().get(poolname);
      if (ausage == null) {
        throw new RuntimeException("After Gc Memory does not exist" + " for " + poolname);
      }
      System.out.println("Usage for pool " + poolname);
      System.out.println("   Before GC: " + busage);
      System.out.println("   After GC: " + ausage);
    }

    // check if memory usage for all memory pools are returned
    List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
    for (MemoryPoolMXBean p : pools) {
      if (!pnames.contains(p.getName())) {
        throw new RuntimeException(
            "GcInfo does not contain " + "memory usage for pool " + p.getName());
      }
    }
  }
 public void handleNotification(Notification notif, Object handback) {
   String type = notif.getType();
   if (type.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
     GarbageCollectionNotificationInfo gcNotif =
         GarbageCollectionNotificationInfo.from((CompositeData) notif.getUserData());
     String source = ((ObjectName) notif.getSource()).getCanonicalName();
     synchronized (synchronizer) {
       if (listenerInvoked.get(source) == null) {
         listenerInvoked.put(((ObjectName) notif.getSource()).getCanonicalName(), gcNotif);
         count++;
         if (count >= number) {
           synchronizer.notify();
         }
       }
     }
   }
 }