public HierarchyDynamicMBean() 
{
    
    hierarchy = LogManager.getLoggerRepository();
    buildDynamicMBeanInfo();
}

 public  void addAppenderEvent(Category logger,
    Appender appender) 
{
    log.debug("addAppenderEvent called: logger="+logger.getName()+
	      ", appender="+appender.getName());
    Notification n = new Notification(ADD_APPENDER+logger.getName(), this, 0);
    n.setUserData(appender);
    log.debug("sending notification.");
    nbs.sendNotification(n);
}

 public ObjectName addLoggerMBean(String name) 
{
    Logger cat = LogManager.exists(name);
    if(cat != null) {
      return addLoggerMBean(cat);
    } else {
      return null;
    }
}

 ObjectName addLoggerMBean(Logger logger) 
{
    String name = logger.getName();
    ObjectName objectName = null;
    try {
      LoggerDynamicMBean loggerMBean = new LoggerDynamicMBean(logger);
      objectName = new ObjectName("log4j", "logger", name);
      if (!server.isRegistered(objectName)) {
        server.registerMBean(loggerMBean, objectName);
        NotificationFilterSupport nfs = new NotificationFilterSupport();
        nfs.enableType(ADD_APPENDER + logger.getName());
        log.debug("---Adding logger [" + name + "] as listener.");
        nbs.addNotificationListener(loggerMBean, nfs, null);
        vAttributes.add(new MBeanAttributeInfo("logger=" + name, "javax.management.ObjectName",
                "The " + name + " logger.", true, true, // this makes the object
                // clickable
                false));
      }
    } catch(Exception e) {
      log.error("Could not add loggerMBean for ["+name+"].", e);
    }
    return objectName;
}

 public  void addNotificationListener(NotificationListener listener,
    NotificationFilter filter,
    Object handback) 
{
    nbs.addNotificationListener(listener, filter, handback);
}

 public Object getAttribute(String attributeName) throws ReflectionException, AttributeNotFoundException, MBeanException 
{
    // Check attributeName is not null to avoid NullPointerException later on
    if (attributeName == null) {
      throw new RuntimeOperationsException(new IllegalArgumentException(
			"Attribute name cannot be null"),
       "Cannot invoke a getter of " + dClassName + " with null attribute name");
    }
    log.debug("Called getAttribute with ["+attributeName+"].");
    // Check for a recognized attributeName and call the corresponding getter
    if (attributeName.equals(THRESHOLD)) {
      return hierarchy.getThreshold();
    } else if(attributeName.startsWith("logger")) {
      int k = attributeName.indexOf("%3D");
      String val = attributeName;
      if(k  > 0) {
	val = attributeName.substring(0, k)+'="+ attributeName.substring(k+3);
      }
      try {
	return new ObjectName("log4j:"+val);
      } catch(Exception e) {
	log.error("Could not create ObjectName" + val);
      }
    }
    // If attributeName has not been recognized throw an AttributeNotFoundException
    throw(new AttributeNotFoundException("Cannot find " + attributeName +
					 " attribute in " + dClassName));
}

 protected Logger getLogger() 
{
    return log;
}

 public MBeanInfo getMBeanInfo() 
{
    //cat.debug("getMBeanInfo called.");
    MBeanAttributeInfo[] attribs = new MBeanAttributeInfo[vAttributes.size()];
    vAttributes.toArray(attribs);
    return new MBeanInfo(dClassName,
			 dDescription,
			 attribs,
			 dConstructors,
			 dOperations,
			 new MBeanNotificationInfo[0]);
}

 public MBeanNotificationInfo[] getNotificationInfo() 
{
    return nbs.getNotificationInfo();
}

 public Object invoke(String operationName,
    Object[] params,
    String[] signature) throws ReflectionException, MBeanException 
{
    if (operationName == null) {
      throw new RuntimeOperationsException(
        new IllegalArgumentException("Operation name cannot be null"),
	"Cannot invoke a null operation in " + dClassName);
    }
    // Check for a recognized operation name and call the corresponding operation
    if(operationName.equals("addLoggerMBean")) {
      return addLoggerMBean((String)params[0]);
    } else {
      throw new ReflectionException(
	    new NoSuchMethodException(operationName),
	    "Cannot find the operation " + operationName + " in " + dClassName);
    }
}

 public  void postRegister(Boolean registrationDone) 
{
    log.debug("postRegister is called.");
    hierarchy.addHierarchyEventListener(this);
    Logger root = hierarchy.getRootLogger();
    addLoggerMBean(root);
}

 public  void removeAppenderEvent(Category cat,
    Appender appender) 
{
    log.debug("removeAppenderCalled: logger="+cat.getName()+
	      ", appender="+appender.getName());
}

 public  void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException 
{
    nbs.removeNotificationListener(listener);
}

 public  void setAttribute(Attribute attribute) throws InvalidAttributeValueException, ReflectionException, AttributeNotFoundException, MBeanException 
{
    // Check attribute is not null to avoid NullPointerException later on
    if (attribute == null) {
      throw new RuntimeOperationsException(
                  new IllegalArgumentException("Attribute cannot be null"),
	  "Cannot invoke a setter of "+dClassName+" with null attribute");
    }
    String name = attribute.getName();
    Object value = attribute.getValue();
    if (name == null) {
      throw new RuntimeOperationsException(
               new IllegalArgumentException("Attribute name cannot be null"),
	       "Cannot invoke the setter of "+dClassName+
	       " with null attribute name");
    }
    if(name.equals(THRESHOLD)) {
      Level l = OptionConverter.toLevel((String) value,
					   hierarchy.getThreshold());
      hierarchy.setThreshold(l);
    }
}