code: private static boolean isSharedFileLockTable() {
          if (!propertyChecked) {
              synchronized (FileChannelImpl.class) {
                  if (!propertyChecked) {
                      /*
                      String value = AccessController.doPrivileged(
                          new GetPropertyAction(
                              "sun.nio.ch.disableSystemWideOverlappingFileLockCheck"));
                      */
                      String value =
                          System.getProperty("sun.nio.ch.disableSystemWideOverlappingFileLockCheck");
                      isSharedFileLockTable = ((value == null) || value.equals("false"));
                      propertyChecked = true;
                  }
              }
          }
          return isSharedFileLockTable;
      }
docs: the same file. This property is used to get 1.4/5.0 behavior if desired.