ipojo/handler/jmx/jmx-handler/src/main/java/org/apache/felix/ipojo/handlers/jmx/MBeanHandler.java - felix - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */
 package org.apache.felix.ipojo.handlers.jmx;

 import java.lang.management.ManagementFactory;
 import java.util.*;

 import javax.management.MBeanRegistration;
 import javax.management.MBeanServer;
 import javax.management.ObjectInstance;
 import javax.management.ObjectName;

 import org.apache.felix.ipojo.FieldInterceptor;
 import org.apache.felix.ipojo.InstanceManager;
 import org.apache.felix.ipojo.PrimitiveHandler;
 import org.apache.felix.ipojo.architecture.HandlerDescription;
 import org.apache.felix.ipojo.metadata.Element;
 import org.apache.felix.ipojo.parser.FieldMetadata;
 import org.apache.felix.ipojo.parser.MethodMetadata;
 import org.apache.felix.ipojo.parser.PojoMetadata;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.ServiceRegistration;

 /**
  * This class implements iPOJO Handler. it builds the dynamic MBean from
  * metadata.xml and exposes it to the MBean Server.
  *
  * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
  */
 public class MBeanHandler extends PrimitiveHandler {

     /**
      * The name of the MBeanRegistration postDeregister method.
      */
     public static final String POST_DEREGISTER_METH_NAME = "postDeregister";

     /**
      * The name of the MBeanRegistration preDeregister method.
      */
     public static final String PRE_DEREGISTER_METH_NAME = "preDeregister";

     /**
      * The name of the MBeanRegistration postRegister method.
      */
     public static final String POST_REGISTER_METH_NAME = "postRegister";

     /**
      * The name of the MBeanRegistration preRegister method.
      */
     public static final String PRE_REGISTER_METH_NAME = "preRegister";

     /**
      * The name of the global configuration element.
      */
     private static final String JMX_CONFIG_ELT = "config";

     /**
      * The name of the global configuration element.
      */
     private static final String JMX_CONFIG_ALT_ELT = "JmxBean";

     /**
      * The name of the component object full name attribute.
      */
     private static final String JMX_OBJ_NAME_ELT = "objectName";

     /**
      * The name of the component object name domain attribute.
      */
     private static final String JMX_OBJ_NAME_DOMAIN_ELT = "domain";

     /**
      * The name of the component object name attribute.
      */
     private static final String JMX_OBJ_NAME_WO_DOMAIN_ELT = "name";

     /**
      * The name of the attribute indicating if the handler uses MOSGi MBean server.
      */
     private static final String JMX_USES_MOSGI_ELT = "usesMOSGi";

     /**
      * The name of a method element.
      */
     private static final String JMX_METHOD_ELT = "method";

     /**
      * The alternative name of a method element.
      */
     private static final String JMX_METHOD_ELT_ALT = "JmxMethod";

     /**
      * The name of the property or method name attribute.
      */
     private static final String JMX_NAME_ELT = "name";

     /**
      * The name of a method description attribute.
      */
     private static final String JMX_DESCRIPTION_ELT = "description";

     /**
      * The name of a property element.
      */
     private static final String JMX_PROPERTY_ELT = "property";

     /**
      * The alternative name of a property element.
      */
     private static final String JMX_PROPERTY_ELT_ALT = "JmxProperty";

     /**
      * The name of the field attribute.
      */
     private static final String JMX_FIELD_ELT = "field";

     /**
      * The name of the notification attribute.
      */
     private static final String JMX_NOTIFICATION_ELT = "notification";

     /**
      * The name of the rights attribute.
      */
     private static final String JMX_RIGHTS_ELT = "rights";

     /**
      * The instance manager. Used to store the InstanceManager instance.
      */
     private InstanceManager m_instanceManager;
     /**
      * The service registration. Used to register and unregister the Dynamic MBean.
      */
     private ServiceRegistration m_serviceRegistration;
     /**
      * Stores data when parsing metadata.xml.
      */
     private JmxConfigFieldMap m_jmxConfigFieldMap;
     /**
      * Stores the Dynamic MBean.
      */
     private DynamicMBeanImpl m_MBean;
     /**
      * Constant storing the name of the class.
      */
     private String m_namespace = "org.apache.felix.ipojo.handlers.jmx";
     /**
      * The flag used to inform if we use the MOSGi framework.
      */
     private boolean m_usesMOSGi;
     /**
      * The ObjectName used to register the MBean.
      */
     private ObjectName m_objectName;
     /**
      * The flag used to inform if the MBean is registered.
      */
     private boolean m_registered;
     /**
      * The ObjectName specified in handler configuration. It can be null.
      */
     private String m_completeObjNameElt;
     /**
      * The ObjectName without domain specified in handler configuration. It can be null.
      */
     private String m_objNameWODomainElt;

     /**
      * The ObjectName domain specified in handler configuration. It can be null.
      */
     private String m_domainElt;
     /**
      * The flag informing if the POJO implements the MBeanRegistration interface.
      */
     private boolean m_registerCallbacks;
     /**
      * The preRegister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
      */
     private MethodMetadata m_preRegisterMeth;
     /**
      * The postRegister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
      */
     private MethodMetadata m_postRegisterMeth;
     /**
      * The preDeregister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
      */
     private MethodMetadata m_preDeregisterMeth;
     /**
      * The postDeregister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
      */
     private MethodMetadata m_postDeregisterMeth;

     /**
      * Constructs the structure JmxConfigFieldMap and the Dynamic Mbean.
      *
      * @param metadata the component metadata
      * @param dict the instance configuration
      */
     public void configure(Element metadata, Dictionary dict) {

         PojoMetadata manipulation = getPojoMetadata();

         m_instanceManager = getInstanceManager();

         m_jmxConfigFieldMap = new JmxConfigFieldMap();

         // Build the hashmap
         Element[] mbeans = metadata.getElements(JMX_CONFIG_ELT, m_namespace);
         if (mbeans == null || mbeans.length == 0) {
             mbeans = metadata.getElements(JMX_CONFIG_ALT_ELT, m_namespace);
         }

         if (mbeans.length != 1) {
             error("A component must have exactly one " + JMX_CONFIG_ELT + " or " + JMX_CONFIG_ALT_ELT + " element.");
             error("The JMX handler configuration is ignored.");
             return;
         }

         Element mbean = mbeans[0];

         // retrieve kind of MBeanServer to use
         m_usesMOSGi = Boolean.parseBoolean(mbean.getAttribute(JMX_USES_MOSGI_ELT));

         // retrieve object name
         m_completeObjNameElt = mbean.getAttribute(JMX_OBJ_NAME_ELT);
         m_domainElt = mbean.getAttribute(JMX_OBJ_NAME_DOMAIN_ELT);
         m_objNameWODomainElt = mbean.getAttribute(JMX_OBJ_NAME_WO_DOMAIN_ELT);

         // test if Pojo is interested in registration callbacks
         m_registerCallbacks = manipulation
             .isInterfaceImplemented(MBeanRegistration.class.getName());
         if (m_registerCallbacks) {
             // don't need to check that methods exist, the pojo implements
             // MBeanRegistration interface
             String[] preRegisterParams = { MBeanServer.class.getName(),
                     ObjectName.class.getName() };
             m_preRegisterMeth = manipulation.getMethod(PRE_REGISTER_METH_NAME,
                 preRegisterParams);

             String[] postRegisterParams = { Boolean.class.getName() };
             m_postRegisterMeth = manipulation.getMethod(
                 POST_REGISTER_METH_NAME, postRegisterParams);

             m_preDeregisterMeth = manipulation.getMethod(
                 PRE_DEREGISTER_METH_NAME, new String[0]);

             m_postDeregisterMeth = manipulation.getMethod(
                 POST_DEREGISTER_METH_NAME, new String[0]);
         }

         // set property
         Element[] attributes = mbean.getElements(JMX_PROPERTY_ELT, m_namespace);
         Element[] attributesAlt = mbean.getElements(JMX_PROPERTY_ELT_ALT, m_namespace);
         List<Element> listOfAttributes = new ArrayList<Element>();
         if (attributes != null) {
         	listOfAttributes.addAll(Arrays.asList(attributes));
         }
         if (attributesAlt != null) {
         	listOfAttributes.addAll(Arrays.asList(attributesAlt));
         }

         Element[] attributesOld = mbeans[0].getElements(JMX_PROPERTY_ELT);
         if (attributesOld != null) {
             warn("The JMX property element should use the '" + m_namespace + "' namespace.");
             listOfAttributes.addAll(Arrays.asList(attributesOld));
         }

         for (Element attribute : listOfAttributes) {
             boolean notif = false;
             String rights;
             String name;
             String field = attribute.getAttribute(JMX_FIELD_ELT);

             if (attribute.containsAttribute(JMX_NAME_ELT)) {
                 name = attribute.getAttribute(JMX_NAME_ELT);
             } else {
                 name = field;
             }
             if (attribute.containsAttribute(JMX_RIGHTS_ELT)) {
                 rights = attribute.getAttribute(JMX_RIGHTS_ELT);
             } else {
                 rights = "r";
             }

             PropertyField property = new PropertyField(name, field, rights,
                 getTypeFromAttributeField(field, manipulation));

             if (attribute.containsAttribute(JMX_NOTIFICATION_ELT)) {
                 notif = Boolean.parseBoolean(attribute
                     .getAttribute(JMX_NOTIFICATION_ELT));
             }

             property.setNotifiable(notif);

             if (notif) {
                 // add the new notifiable property in structure
                 NotificationField notification = new NotificationField(
                     name, this.getClass().getName() + "." + field, null);
                 m_jmxConfigFieldMap.addNotificationFromName(name,
                     notification);
             }
             m_jmxConfigFieldMap.addPropertyFromName(name, property);
             getInstanceManager().register(manipulation.getField(field),
                 this);
             info("property exposed:" + name + " " + field + ":"
                     + getTypeFromAttributeField(field, manipulation) + " "
                     + rights + ", Notif=" + notif);
         }

         // set methods
         Element[] methods = mbean.getElements(JMX_METHOD_ELT, m_namespace);
         Element[] methodsAlt = mbean.getElements(JMX_METHOD_ELT_ALT, m_namespace);
         List<Element> listOfMethods = new ArrayList<Element>();
         if (methods != null) {
         	listOfMethods.addAll(Arrays.asList(methods));
         }
         if (methodsAlt != null) {
         	listOfMethods.addAll(Arrays.asList(methodsAlt));
         }

         Element[] methodsOld = mbeans[0].getElements(JMX_PROPERTY_ELT);
         if (methodsOld != null) {
             warn("The JMX method element should use the '" + m_namespace + "' namespace.");
             listOfMethods.addAll(Arrays.asList(methodsOld));
         }

         for (Element method : listOfMethods) {
             String name = method.getAttribute(JMX_NAME_ELT);
             if (name == null) {
                 name = method.getAttribute("method");
             }
             String description = null;
             if (method.containsAttribute(JMX_DESCRIPTION_ELT)) {
                 description = method.getAttribute(JMX_DESCRIPTION_ELT);
             }

             MethodField[] meth = getMethodsFromName(name, manipulation,
                 description);

             for (int j = 0; j < meth.length; j++) {
                 m_jmxConfigFieldMap.addMethodFromName(name, meth[j]);

                 info("method exposed:" + meth[j].getReturnType() + " " + name);
             }
         }

     }

     /**
      * Registers the Dynamic Mbean.
      */
     public void start() {
         // create the corresponding MBean
         if (m_registerCallbacks) {
             m_MBean = new DynamicMBeanWRegisterImpl(m_jmxConfigFieldMap,
                 m_instanceManager, m_preRegisterMeth, m_postRegisterMeth,
                 m_preDeregisterMeth, m_postDeregisterMeth);
         } else {
             m_MBean = new DynamicMBeanImpl(m_jmxConfigFieldMap,
                 m_instanceManager);
         }

         if (m_usesMOSGi) {
             // use whiteboard pattern to register MBean

             if (m_serviceRegistration != null) {
                 m_serviceRegistration.unregister();
             }

             // Register the ManagedService
             BundleContext bundleContext = m_instanceManager.getContext();
             Dictionary<String, String> properties = new Hashtable<String, String>();
             try {
                 m_objectName = new ObjectName(getObjectNameString());

                 properties.put("jmxagent.objectName", m_objectName.toString());

                 m_serviceRegistration = bundleContext.registerService(
                     javax.management.DynamicMBean.class.getName(), m_MBean,
                     properties);

                 m_registered = true;
             } catch (Exception e) {
                 e.printStackTrace();
             }
         } else {
             try {
                 m_objectName = new ObjectName(getObjectNameString());
                 ObjectInstance instance = ManagementFactory
                     .getPlatformMBeanServer().registerMBean(m_MBean,
                         m_objectName);

                 // we must retrieve object name used to register the MBean.
                 // It can have been changed by preRegister method of
                 // MBeanRegistration interface.
                 if (m_registerCallbacks) {
                     m_objectName = instance.getObjectName();
                 }

                 m_registered = true;
             } catch (Exception e) {
                 error("Registration of MBean failed.", e);
             }
         }
     }

     /**
      * Returns the object name of the exposed component.
      *
      * @return the object name of the exposed component.
      */
     private String getObjectNameString() {
         if (m_completeObjNameElt != null) {
             return m_completeObjNameElt;
         }

         String domain;
         if (m_domainElt != null) {
             domain = m_domainElt;
         } else {
             domain = getPackageName(m_instanceManager.getClassName());
         }

         String name = "type=" + m_instanceManager.getClassName() + ",instance="
                 + m_instanceManager.getInstanceName();
         if (m_objNameWODomainElt != null) {
             name = "name=" + m_objNameWODomainElt;
         }

         StringBuffer sb = new StringBuffer();
         if ((domain != null) && (domain.length() > 0)) {
             sb.append(domain + ":");
         }
         sb.append(name);

         info("Computed Objectname: " + sb.toString());

         return sb.toString();
     }

     /**
      * Extracts the package name from of given type.
      *
      * @param className the type name.
      * @return the package name of the given type.
      */
     private String getPackageName(String className) {
         String packageName = "";

         int plotIdx = className.lastIndexOf(".");
         if (plotIdx != -1) {
             packageName = className.substring(0, plotIdx);
         }

         return packageName;
     }

     /**
      * Unregisters the Dynamic Mbean.
      */
     public void stop() {
         if (m_usesMOSGi) {
             if (m_serviceRegistration != null) {
                 m_serviceRegistration.unregister();
             }
         } else {
             if (m_objectName != null) {
                 try {
                     ManagementFactory.getPlatformMBeanServer().unregisterMBean(
                         m_objectName);
                 } catch (Exception e) {
                     error("Unregistration of MBean failed.", e);
                 }
                 m_objectName = null;
             }
         }

         m_MBean = null;
         m_registered = false;
     }

     /**
      * Called when a POJO member is modified externally.
      *
      * @param pojo the modified POJO object
      * @param fieldName the name of the modified field
      * @param value the new value of the field
      * @see FieldInterceptor#onSet(Object, String, Object)
      */
     public void onSet(Object pojo, String fieldName, Object value) {
         // Check if the field is a configurable property

         PropertyField propertyField = (PropertyField) m_jmxConfigFieldMap
             .getPropertyFromField(fieldName);
         if (propertyField != null) {
             if (propertyField.isNotifiable()) {
                 // TODO should send notif only when value has changed to a value
                 // different than the last one.
                 m_MBean.sendNotification(propertyField.getName() + " changed",
                     propertyField.getName(), propertyField.getType(),
                     propertyField.getValue(), value);
             }
             propertyField.setValue(value);
         }
     }

     /**
      * Called when a POJO member is read by the MBean.
      *
      * @param pojo the read POJO object.
      * @param fieldName the name of the modified field
      * @param value the old value of the field
      * @return the (injected) value of the field
      * @see FieldInterceptor#onGet(Object, String, Object)
      */
     public Object onGet(Object pojo, String fieldName, Object value) {

         // Check if the field is a configurable property
         PropertyField propertyField = (PropertyField) m_jmxConfigFieldMap
             .getPropertyFromField(fieldName);
         if (propertyField != null) {
         	// Do we have a value to inject ?
         	Object v = propertyField.getValue();
         	if (v == null) {
         		String type = propertyField.getType();
     	        if ("boolean".equals(type)) { v = Boolean.FALSE; }
     	        else if ("byte".equals(type)) { v = new Byte((byte) 0); }
     	        else if ("short".equals(type)) { v = new Short((short) 0); }
     	        else if ("int".equals(type)) { v = new Integer(0); }
     	        else if ("long".equals(type)) { v = new Long(0); }
     	        else if ("float".equals(type)) { v = new Float(0); }
     	        else if ("double".equals(type)) { v =new Double(0); }
     	        else if ("char".equals(type)) { v = new Character((char) 0); }

     	        return v;
     	    }
             m_instanceManager.onSet(pojo, fieldName, propertyField.getValue());
             return propertyField.getValue();
         }
         return value;
     }

     /**
      * Gets the type from a field name.
      *
      * @param fieldRequire the name of the required field
      * @param manipulation the metadata extracted from metadata.xml file
      * @return the type of the field or {@code null} if it wasn't found
      */
     private static String getTypeFromAttributeField(String fieldRequire,
             PojoMetadata manipulation) {

         FieldMetadata field = manipulation.getField(fieldRequire);
         if (field == null) {
             return null;
         } else {
             return FieldMetadata.getReflectionType(field.getFieldType());
         }
     }

     /**
      * Gets all the methods available which get this name.
      *
      * @param methodName the name of the required methods
      * @param manipulation the metadata extract from metadata.xml file
      * @param description the description which appears in JMX console
      * @return the array of methods with the right name
      */
     private MethodField[] getMethodsFromName(String methodName,
             PojoMetadata manipulation, String description) {

         MethodMetadata[] methods = manipulation.getMethods(methodName);
         if (methods.length == 0) {
             return null;
         }

         MethodField[] ret = new MethodField[methods.length];

         if (methods.length == 1) {
             ret[0] = new MethodField(methods[0], description);
             return ret;
         } else {
             for (int i = 0; i < methods.length; i++) {
                 ret[i] = new MethodField(methods[i], description);
             }
             return ret;
         }
     }

     /**
      * Gets the JMX handler description.
      *
      * @return the JMX handler description.
      * @see org.apache.felix.ipojo.Handler#getDescription()
      */
     public HandlerDescription getDescription() {
         return new JMXHandlerDescription(this);
     }

     /**
      * Returns the objectName used to register the MBean. If the MBean is not registered, return an empty string.
      *
      * @return the objectName used to register the MBean.
      * @see org.apache.felix.ipojo.Handler#getDescription()
      */
     public String getUsedObjectName() {
         if (m_objectName != null) {
             return m_objectName.toString();
         } else {
             return "";
         }
     }

     /**
      * Returns true if the MBean is registered.
      *
      * @return true if the MBean is registered.
      */
     public boolean isRegistered() {
         return m_registered;
     }

     /**
      * Returns true if the MBean must be registered thanks to white board pattern of MOSGi.
      *
      * @return {@code true} if the MBean must be registered thanks to white board pattern of MOSGi, false otherwise.
      */
     public boolean isUsesMOSGi() {
         return m_usesMOSGi;
     }

     /**
      * Returns true if the MOSGi framework is present on the OSGi platform.
      *
      * @return {@code true} if the MOSGi framework is present on the OSGi platform, false otherwise.
      */
     public boolean isMOSGiExists() {
         for (Bundle bundle : m_instanceManager.getContext().getBundles()) {
             String symbolicName = bundle.getSymbolicName();
             if ("org.apache.felix.mosgi.jmx.agent".equals(symbolicName)) {
                 return true;
             }
         }

         return false;
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/
	package org.apache.felix.ipojo.handlers.jmx;

	import java.lang.management.ManagementFactory;
	import java.util.*;

	import javax.management.MBeanRegistration;
	import javax.management.MBeanServer;
	import javax.management.ObjectInstance;
	import javax.management.ObjectName;

	import org.apache.felix.ipojo.FieldInterceptor;
	import org.apache.felix.ipojo.InstanceManager;
	import org.apache.felix.ipojo.PrimitiveHandler;
	import org.apache.felix.ipojo.architecture.HandlerDescription;
	import org.apache.felix.ipojo.metadata.Element;
	import org.apache.felix.ipojo.parser.FieldMetadata;
	import org.apache.felix.ipojo.parser.MethodMetadata;
	import org.apache.felix.ipojo.parser.PojoMetadata;
	import org.osgi.framework.Bundle;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.ServiceRegistration;

	/**
	* This class implements iPOJO Handler. it builds the dynamic MBean from
	* metadata.xml and exposes it to the MBean Server.
	*
	* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
	*/
	public class MBeanHandler extends PrimitiveHandler {

	/**
	* The name of the MBeanRegistration postDeregister method.
	*/
	public static final String POST_DEREGISTER_METH_NAME = "postDeregister";

	/**
	* The name of the MBeanRegistration preDeregister method.
	*/
	public static final String PRE_DEREGISTER_METH_NAME = "preDeregister";

	/**
	* The name of the MBeanRegistration postRegister method.
	*/
	public static final String POST_REGISTER_METH_NAME = "postRegister";

	/**
	* The name of the MBeanRegistration preRegister method.
	*/
	public static final String PRE_REGISTER_METH_NAME = "preRegister";

	/**
	* The name of the global configuration element.
	*/
	private static final String JMX_CONFIG_ELT = "config";

	/**
	* The name of the global configuration element.
	*/
	private static final String JMX_CONFIG_ALT_ELT = "JmxBean";

	/**
	* The name of the component object full name attribute.
	*/
	private static final String JMX_OBJ_NAME_ELT = "objectName";

	/**
	* The name of the component object name domain attribute.
	*/
	private static final String JMX_OBJ_NAME_DOMAIN_ELT = "domain";

	/**
	* The name of the component object name attribute.
	*/
	private static final String JMX_OBJ_NAME_WO_DOMAIN_ELT = "name";

	/**
	* The name of the attribute indicating if the handler uses MOSGi MBean server.
	*/
	private static final String JMX_USES_MOSGI_ELT = "usesMOSGi";

	/**
	* The name of a method element.
	*/
	private static final String JMX_METHOD_ELT = "method";

	/**
	* The alternative name of a method element.
	*/
	private static final String JMX_METHOD_ELT_ALT = "JmxMethod";

	/**
	* The name of the property or method name attribute.
	*/
	private static final String JMX_NAME_ELT = "name";

	/**
	* The name of a method description attribute.
	*/
	private static final String JMX_DESCRIPTION_ELT = "description";

	/**
	* The name of a property element.
	*/
	private static final String JMX_PROPERTY_ELT = "property";

	/**
	* The alternative name of a property element.
	*/
	private static final String JMX_PROPERTY_ELT_ALT = "JmxProperty";

	/**
	* The name of the field attribute.
	*/
	private static final String JMX_FIELD_ELT = "field";

	/**
	* The name of the notification attribute.
	*/
	private static final String JMX_NOTIFICATION_ELT = "notification";

	/**
	* The name of the rights attribute.
	*/
	private static final String JMX_RIGHTS_ELT = "rights";

	/**
	* The instance manager. Used to store the InstanceManager instance.
	*/
	private InstanceManager m_instanceManager;
	/**
	* The service registration. Used to register and unregister the Dynamic MBean.
	*/
	private ServiceRegistration m_serviceRegistration;
	/**
	* Stores data when parsing metadata.xml.
	*/
	private JmxConfigFieldMap m_jmxConfigFieldMap;
	/**
	* Stores the Dynamic MBean.
	*/
	private DynamicMBeanImpl m_MBean;
	/**
	* Constant storing the name of the class.
	*/
	private String m_namespace = "org.apache.felix.ipojo.handlers.jmx";
	/**
	* The flag used to inform if we use the MOSGi framework.
	*/
	private boolean m_usesMOSGi;
	/**
	* The ObjectName used to register the MBean.
	*/
	private ObjectName m_objectName;
	/**
	* The flag used to inform if the MBean is registered.
	*/
	private boolean m_registered;
	/**
	* The ObjectName specified in handler configuration. It can be null.
	*/
	private String m_completeObjNameElt;
	/**
	* The ObjectName without domain specified in handler configuration. It can be null.
	*/
	private String m_objNameWODomainElt;

	/**
	* The ObjectName domain specified in handler configuration. It can be null.
	*/
	private String m_domainElt;
	/**
	* The flag informing if the POJO implements the MBeanRegistration interface.
	*/
	private boolean m_registerCallbacks;
	/**
	* The preRegister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
	*/
	private MethodMetadata m_preRegisterMeth;
	/**
	* The postRegister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
	*/
	private MethodMetadata m_postRegisterMeth;
	/**
	* The preDeregister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
	*/
	private MethodMetadata m_preDeregisterMeth;
	/**
	* The postDeregister method of MBeanRegistration interface. It is null if POJO doesn't implement MBeanRegistration interface.
	*/
	private MethodMetadata m_postDeregisterMeth;

	/**
	* Constructs the structure JmxConfigFieldMap and the Dynamic Mbean.
	*
	* @param metadata the component metadata
	* @param dict the instance configuration
	*/
	public void configure(Element metadata, Dictionary dict) {

	PojoMetadata manipulation = getPojoMetadata();

	m_instanceManager = getInstanceManager();

	m_jmxConfigFieldMap = new JmxConfigFieldMap();

	// Build the hashmap
	Element[] mbeans = metadata.getElements(JMX_CONFIG_ELT, m_namespace);
	if (mbeans == null \|\| mbeans.length == 0) {
	mbeans = metadata.getElements(JMX_CONFIG_ALT_ELT, m_namespace);
	}

	if (mbeans.length != 1) {
	error("A component must have exactly one " + JMX_CONFIG_ELT + " or " + JMX_CONFIG_ALT_ELT + " element.");
	error("The JMX handler configuration is ignored.");
	return;
	}

	Element mbean = mbeans[0];

	// retrieve kind of MBeanServer to use
	m_usesMOSGi = Boolean.parseBoolean(mbean.getAttribute(JMX_USES_MOSGI_ELT));

	// retrieve object name
	m_completeObjNameElt = mbean.getAttribute(JMX_OBJ_NAME_ELT);
	m_domainElt = mbean.getAttribute(JMX_OBJ_NAME_DOMAIN_ELT);
	m_objNameWODomainElt = mbean.getAttribute(JMX_OBJ_NAME_WO_DOMAIN_ELT);

	// test if Pojo is interested in registration callbacks
	m_registerCallbacks = manipulation
	.isInterfaceImplemented(MBeanRegistration.class.getName());
	if (m_registerCallbacks) {
	// don't need to check that methods exist, the pojo implements
	// MBeanRegistration interface
	String[] preRegisterParams = { MBeanServer.class.getName(),
	ObjectName.class.getName() };
	m_preRegisterMeth = manipulation.getMethod(PRE_REGISTER_METH_NAME,
	preRegisterParams);

	String[] postRegisterParams = { Boolean.class.getName() };
	m_postRegisterMeth = manipulation.getMethod(
	POST_REGISTER_METH_NAME, postRegisterParams);

	m_preDeregisterMeth = manipulation.getMethod(
	PRE_DEREGISTER_METH_NAME, new String[0]);

	m_postDeregisterMeth = manipulation.getMethod(
	POST_DEREGISTER_METH_NAME, new String[0]);
	}

	// set property
	Element[] attributes = mbean.getElements(JMX_PROPERTY_ELT, m_namespace);
	Element[] attributesAlt = mbean.getElements(JMX_PROPERTY_ELT_ALT, m_namespace);
	List<Element> listOfAttributes = new ArrayList<Element>();
	if (attributes != null) {
	listOfAttributes.addAll(Arrays.asList(attributes));
	}
	if (attributesAlt != null) {
	listOfAttributes.addAll(Arrays.asList(attributesAlt));
	}

	Element[] attributesOld = mbeans[0].getElements(JMX_PROPERTY_ELT);
	if (attributesOld != null) {
	warn("The JMX property element should use the '" + m_namespace + "' namespace.");
	listOfAttributes.addAll(Arrays.asList(attributesOld));
	}

	for (Element attribute : listOfAttributes) {
	boolean notif = false;
	String rights;
	String name;
	String field = attribute.getAttribute(JMX_FIELD_ELT);

	if (attribute.containsAttribute(JMX_NAME_ELT)) {
	name = attribute.getAttribute(JMX_NAME_ELT);
	} else {
	name = field;
	}
	if (attribute.containsAttribute(JMX_RIGHTS_ELT)) {
	rights = attribute.getAttribute(JMX_RIGHTS_ELT);
	} else {
	rights = "r";
	}

	PropertyField property = new PropertyField(name, field, rights,
	getTypeFromAttributeField(field, manipulation));

	if (attribute.containsAttribute(JMX_NOTIFICATION_ELT)) {
	notif = Boolean.parseBoolean(attribute
	.getAttribute(JMX_NOTIFICATION_ELT));
	}

	property.setNotifiable(notif);

	if (notif) {
	// add the new notifiable property in structure
	NotificationField notification = new NotificationField(
	name, this.getClass().getName() + "." + field, null);
	m_jmxConfigFieldMap.addNotificationFromName(name,
	notification);
	}
	m_jmxConfigFieldMap.addPropertyFromName(name, property);
	getInstanceManager().register(manipulation.getField(field),
	this);
	info("property exposed:" + name + " " + field + ":"
	+ getTypeFromAttributeField(field, manipulation) + " "
	+ rights + ", Notif=" + notif);
	}

	// set methods
	Element[] methods = mbean.getElements(JMX_METHOD_ELT, m_namespace);
	Element[] methodsAlt = mbean.getElements(JMX_METHOD_ELT_ALT, m_namespace);
	List<Element> listOfMethods = new ArrayList<Element>();
	if (methods != null) {
	listOfMethods.addAll(Arrays.asList(methods));
	}
	if (methodsAlt != null) {
	listOfMethods.addAll(Arrays.asList(methodsAlt));
	}

	Element[] methodsOld = mbeans[0].getElements(JMX_PROPERTY_ELT);
	if (methodsOld != null) {
	warn("The JMX method element should use the '" + m_namespace + "' namespace.");
	listOfMethods.addAll(Arrays.asList(methodsOld));
	}

	for (Element method : listOfMethods) {
	String name = method.getAttribute(JMX_NAME_ELT);
	if (name == null) {
	name = method.getAttribute("method");
	}
	String description = null;
	if (method.containsAttribute(JMX_DESCRIPTION_ELT)) {
	description = method.getAttribute(JMX_DESCRIPTION_ELT);
	}

	MethodField[] meth = getMethodsFromName(name, manipulation,
	description);

	for (int j = 0; j < meth.length; j++) {
	m_jmxConfigFieldMap.addMethodFromName(name, meth[j]);

	info("method exposed:" + meth[j].getReturnType() + " " + name);
	}
	}

	}

	/**
	* Registers the Dynamic Mbean.
	*/
	public void start() {
	// create the corresponding MBean
	if (m_registerCallbacks) {
	m_MBean = new DynamicMBeanWRegisterImpl(m_jmxConfigFieldMap,
	m_instanceManager, m_preRegisterMeth, m_postRegisterMeth,
	m_preDeregisterMeth, m_postDeregisterMeth);
	} else {
	m_MBean = new DynamicMBeanImpl(m_jmxConfigFieldMap,
	m_instanceManager);
	}

	if (m_usesMOSGi) {
	// use whiteboard pattern to register MBean

	if (m_serviceRegistration != null) {
	m_serviceRegistration.unregister();
	}

	// Register the ManagedService
	BundleContext bundleContext = m_instanceManager.getContext();
	Dictionary<String, String> properties = new Hashtable<String, String>();
	try {
	m_objectName = new ObjectName(getObjectNameString());

	properties.put("jmxagent.objectName", m_objectName.toString());

	m_serviceRegistration = bundleContext.registerService(
	javax.management.DynamicMBean.class.getName(), m_MBean,
	properties);

	m_registered = true;
	} catch (Exception e) {
	e.printStackTrace();
	}
	} else {
	try {
	m_objectName = new ObjectName(getObjectNameString());
	ObjectInstance instance = ManagementFactory
	.getPlatformMBeanServer().registerMBean(m_MBean,
	m_objectName);

	// we must retrieve object name used to register the MBean.
	// It can have been changed by preRegister method of
	// MBeanRegistration interface.
	if (m_registerCallbacks) {
	m_objectName = instance.getObjectName();
	}

	m_registered = true;
	} catch (Exception e) {
	error("Registration of MBean failed.", e);
	}
	}
	}

	/**
	* Returns the object name of the exposed component.
	*
	* @return the object name of the exposed component.
	*/
	private String getObjectNameString() {
	if (m_completeObjNameElt != null) {
	return m_completeObjNameElt;
	}

	String domain;
	if (m_domainElt != null) {
	domain = m_domainElt;
	} else {
	domain = getPackageName(m_instanceManager.getClassName());
	}

	String name = "type=" + m_instanceManager.getClassName() + ",instance="
	+ m_instanceManager.getInstanceName();
	if (m_objNameWODomainElt != null) {
	name = "name=" + m_objNameWODomainElt;
	}

	StringBuffer sb = new StringBuffer();
	if ((domain != null) && (domain.length() > 0)) {
	sb.append(domain + ":");
	}
	sb.append(name);

	info("Computed Objectname: " + sb.toString());

	return sb.toString();
	}

	/**
	* Extracts the package name from of given type.
	*
	* @param className the type name.
	* @return the package name of the given type.
	*/
	private String getPackageName(String className) {
	String packageName = "";

	int plotIdx = className.lastIndexOf(".");
	if (plotIdx != -1) {
	packageName = className.substring(0, plotIdx);
	}

	return packageName;
	}

	/**
	* Unregisters the Dynamic Mbean.
	*/
	public void stop() {
	if (m_usesMOSGi) {
	if (m_serviceRegistration != null) {
	m_serviceRegistration.unregister();
	}
	} else {
	if (m_objectName != null) {
	try {
	ManagementFactory.getPlatformMBeanServer().unregisterMBean(
	m_objectName);
	} catch (Exception e) {
	error("Unregistration of MBean failed.", e);
	}
	m_objectName = null;
	}
	}

	m_MBean = null;
	m_registered = false;
	}

	/**
	* Called when a POJO member is modified externally.
	*
	* @param pojo the modified POJO object
	* @param fieldName the name of the modified field
	* @param value the new value of the field
	* @see FieldInterceptor#onSet(Object, String, Object)
	*/
	public void onSet(Object pojo, String fieldName, Object value) {
	// Check if the field is a configurable property

	PropertyField propertyField = (PropertyField) m_jmxConfigFieldMap
	.getPropertyFromField(fieldName);
	if (propertyField != null) {
	if (propertyField.isNotifiable()) {
	// TODO should send notif only when value has changed to a value
	// different than the last one.
	m_MBean.sendNotification(propertyField.getName() + " changed",
	propertyField.getName(), propertyField.getType(),
	propertyField.getValue(), value);
	}
	propertyField.setValue(value);
	}
	}

	/**
	* Called when a POJO member is read by the MBean.
	*
	* @param pojo the read POJO object.
	* @param fieldName the name of the modified field
	* @param value the old value of the field
	* @return the (injected) value of the field
	* @see FieldInterceptor#onGet(Object, String, Object)
	*/
	public Object onGet(Object pojo, String fieldName, Object value) {

	// Check if the field is a configurable property
	PropertyField propertyField = (PropertyField) m_jmxConfigFieldMap
	.getPropertyFromField(fieldName);
	if (propertyField != null) {
	// Do we have a value to inject ?
	Object v = propertyField.getValue();
	if (v == null) {
	String type = propertyField.getType();
	if ("boolean".equals(type)) { v = Boolean.FALSE; }
	else if ("byte".equals(type)) { v = new Byte((byte) 0); }
	else if ("short".equals(type)) { v = new Short((short) 0); }
	else if ("int".equals(type)) { v = new Integer(0); }
	else if ("long".equals(type)) { v = new Long(0); }
	else if ("float".equals(type)) { v = new Float(0); }
	else if ("double".equals(type)) { v =new Double(0); }
	else if ("char".equals(type)) { v = new Character((char) 0); }

	return v;
	}
	m_instanceManager.onSet(pojo, fieldName, propertyField.getValue());
	return propertyField.getValue();
	}
	return value;
	}

	/**
	* Gets the type from a field name.
	*
	* @param fieldRequire the name of the required field
	* @param manipulation the metadata extracted from metadata.xml file
	* @return the type of the field or {@code null} if it wasn't found
	*/
	private static String getTypeFromAttributeField(String fieldRequire,
	PojoMetadata manipulation) {

	FieldMetadata field = manipulation.getField(fieldRequire);
	if (field == null) {
	return null;
	} else {
	return FieldMetadata.getReflectionType(field.getFieldType());
	}
	}

	/**
	* Gets all the methods available which get this name.
	*
	* @param methodName the name of the required methods
	* @param manipulation the metadata extract from metadata.xml file
	* @param description the description which appears in JMX console
	* @return the array of methods with the right name
	*/
	private MethodField[] getMethodsFromName(String methodName,
	PojoMetadata manipulation, String description) {

	MethodMetadata[] methods = manipulation.getMethods(methodName);
	if (methods.length == 0) {
	return null;
	}

	MethodField[] ret = new MethodField[methods.length];

	if (methods.length == 1) {
	ret[0] = new MethodField(methods[0], description);
	return ret;
	} else {
	for (int i = 0; i < methods.length; i++) {
	ret[i] = new MethodField(methods[i], description);
	}
	return ret;
	}
	}

	/**
	* Gets the JMX handler description.
	*
	* @return the JMX handler description.
	* @see org.apache.felix.ipojo.Handler#getDescription()
	*/
	public HandlerDescription getDescription() {
	return new JMXHandlerDescription(this);
	}

	/**
	* Returns the objectName used to register the MBean. If the MBean is not registered, return an empty string.
	*
	* @return the objectName used to register the MBean.
	* @see org.apache.felix.ipojo.Handler#getDescription()
	*/
	public String getUsedObjectName() {
	if (m_objectName != null) {
	return m_objectName.toString();
	} else {
	return "";
	}
	}

	/**
	* Returns true if the MBean is registered.
	*
	* @return true if the MBean is registered.
	*/
	public boolean isRegistered() {
	return m_registered;
	}

	/**
	* Returns true if the MBean must be registered thanks to white board pattern of MOSGi.
	*
	* @return {@code true} if the MBean must be registered thanks to white board pattern of MOSGi, false otherwise.
	*/
	public boolean isUsesMOSGi() {
	return m_usesMOSGi;
	}

	/**
	* Returns true if the MOSGi framework is present on the OSGi platform.
	*
	* @return {@code true} if the MOSGi framework is present on the OSGi platform, false otherwise.
	*/
	public boolean isMOSGiExists() {
	for (Bundle bundle : m_instanceManager.getContext().getBundles()) {
	String symbolicName = bundle.getSymbolicName();
	if ("org.apache.felix.mosgi.jmx.agent".equals(symbolicName)) {
	return true;
	}
	}

	return false;
	}
	}