code: public static void shutdown()
      {
          synchronized(lock) {
              for(Iterator it = loadedHMs.iterator(); it.hasNext();)
              {
                  ((HashMap) it.next()).clear();
              }
              loadedHMs.clear();
              loadedHMs = null;
          }
          currentBrokerMap = null;
      }
docs: Clean up static fields and any registered ThreadLocal contents to grant a clean
  shutdown/reload of OJB within re/hot-deployable applications.