public LoggerDynamicMBean(Logger logger) 
{
     
    this.logger = logger;
    buildDynamicMBeanInfo();
}

  void addAppender(String appenderClass,
    String appenderName) 
{
    cat.debug("addAppender called with "+appenderClass+", "+appenderName);
    Appender appender = (Appender)
       OptionConverter.instantiateByClassName(appenderClass,
					      org.apache.log4j.Appender.class,
					      null);
    appender.setName(appenderName);
    logger.addAppender(appender);
    //appenderMBeanRegistration();
}

  void appenderMBeanRegistration() 
{
    Enumeration enumeration = logger.getAllAppenders();
    while(enumeration.hasMoreElements()) {
      Appender appender = (Appender) enumeration.nextElement();
      registerAppenderMBean(appender);
    }
}

 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");
    }
    // Check for a recognized attributeName and call the corresponding getter
    if (attributeName.equals("name")) {
      return logger.getName();
    }  else if(attributeName.equals("priority")) {
      Level l = logger.getLevel();
      if(l == null) {
	return null;
      } else {
	return l.toString();
      }
    } else if(attributeName.startsWith("appender=")) {
      try {
	return new ObjectName("log4j:"+attributeName );
      } catch(Exception e) {
	cat.error("Could not create ObjectName" + attributeName);
      }
    }
    // If attributeName has not been recognized throw an AttributeNotFoundException
    throw(new AttributeNotFoundException("Cannot find " + attributeName +
					 " attribute in " + dClassName));
}

 protected Logger getLogger() 
{
    return logger;
}

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

 public  void handleNotification(Notification notification,
    Object handback) 
{
    cat.debug("Received notification: "+notification.getType());
    registerAppenderMBean((Appender) notification.getUserData() );
}

 public Object invoke(String operationName,
    Object[] params,
    String[] signature) throws ReflectionException, MBeanException 
{
    if(operationName.equals("addAppender")) {
      addAppender((String) params[0], (String) params[1]);
      return "Hello world.";
    }
    return null;
}

 public  void postRegister(Boolean registrationDone) 
{
    appenderMBeanRegistration();
}

  void registerAppenderMBean(Appender appender) 
{
    String name = appender.getName();
    cat.debug("Adding AppenderMBean for appender named "+name);
    ObjectName objectName = null;
    try {
      AppenderDynamicMBean appenderMBean = new AppenderDynamicMBean(appender);
      objectName = new ObjectName("log4j", "appender", name);
      if (!server.isRegistered(objectName)) {
        server.registerMBean(appenderMBean, objectName);
        dAttributes.add(new MBeanAttributeInfo("appender=" + name, "javax.management.ObjectName",
                "The " + name + " appender.", true, true, false));
      }
    } catch(Exception e) {
      cat.error("Could not add appenderMBean for ["+name+"].", e);
    }
}

 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("priority")) {
      if (value instanceof String) {
	String s = (String) value;
	Level p = logger.getLevel();
	if(s.equalsIgnoreCase("NULL")) {
	  p = null;
	} else {
	  p = OptionConverter.toLevel(s, p);
	}
	logger.setLevel(p);
      }
    } else {
      throw(new AttributeNotFoundException("Attribute " + name +
					   " not found in " +
					   this.getClass().getName()));
    }
}