/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.jmx.export;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.management.DynamicMBean;
import javax.management.JMException;
import javax.management.MBeanException;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.NotCompliantMBeanException;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.StandardMBean;
import javax.management.modelmbean.ModelMBean;
import javax.management.modelmbean.ModelMBeanInfo;
import javax.management.modelmbean.RequiredModelMBean;

import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.scope.ScopedProxyUtils;
import org.springframework.aop.support.AopUtils;
import org.springframework.aop.target.LazyInitTargetSource;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.CannotLoadBeanClassException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.SmartInitializingSingleton;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.core.Constants;
import org.springframework.jmx.export.assembler.AutodetectCapableMBeanInfoAssembler;
import org.springframework.jmx.export.assembler.MBeanInfoAssembler;
import org.springframework.jmx.export.assembler.SimpleReflectiveMBeanInfoAssembler;
import org.springframework.jmx.export.naming.KeyNamingStrategy;
import org.springframework.jmx.export.naming.ObjectNamingStrategy;
import org.springframework.jmx.export.naming.SelfNaming;
import org.springframework.jmx.export.notification.ModelMBeanNotificationPublisher;
import org.springframework.jmx.export.notification.NotificationPublisherAware;
import org.springframework.jmx.support.JmxUtils;
import org.springframework.jmx.support.MBeanRegistrationSupport;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ObjectUtils;

/**
 * JMX exporter that allows for exposing any <i>Spring-managed bean</i> to a
 * JMX {@link javax.management.MBeanServer}, without the need to define any
 * JMX-specific information in the bean classes.
 *
 * <p>If a bean implements one of the JMX management interfaces, MBeanExporter can
 * simply register the MBean with the server through its autodetection process.
 *
 * <p>If a bean does not implement one of the JMX management interfaces, MBeanExporter
 * will create the management information using the supplied {@link MBeanInfoAssembler}.
 *
 * <p>A list of {@link MBeanExporterListener MBeanExporterListeners} can be registered
 * via the {@link #setListeners(MBeanExporterListener[]) listeners} property, allowing
 * application code to be notified of MBean registration and unregistration events.
 *
 * <p>This exporter is compatible with MBeans as well as MXBeans.
 *
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @author Rick Evans
 * @author Mark Fisher
 * @author Stephane Nicoll
 * @since 1.2
 * @see #setBeans
 * @see #setAutodetect
 * @see #setAssembler
 * @see #setListeners
 * @see org.springframework.jmx.export.assembler.MBeanInfoAssembler
 * @see MBeanExporterListener
 */
public class MBeanExporter extends MBeanRegistrationSupport implements MBeanExportOperations,
		BeanClassLoaderAware, BeanFactoryAware, InitializingBean, SmartInitializingSingleton, DisposableBean {

	/**
	 * Autodetection mode indicating that no autodetection should be used.
	 */
	public static final int AUTODETECT_NONE = 0;

	/**
	 * Autodetection mode indicating that only valid MBeans should be autodetected.
	 */
	public static final int AUTODETECT_MBEAN = 1;

	/**
	 * Autodetection mode indicating that only the {@link MBeanInfoAssembler} should be able
	 * to autodetect beans.
	 */
	public static final int AUTODETECT_ASSEMBLER = 2;

	/**
	 * Autodetection mode indicating that all autodetection mechanisms should be used.
	 */
	public static final int AUTODETECT_ALL = AUTODETECT_MBEAN | AUTODETECT_ASSEMBLER;


	/**
	 * Wildcard used to map a {@link javax.management.NotificationListener}
	 * to all MBeans registered by the {@code MBeanExporter}.
	 */
	private static final String WILDCARD = "*";

	/** Constant for the JMX {@code mr_type} "ObjectReference" */
	private static final String MR_TYPE_OBJECT_REFERENCE = "ObjectReference";

	/** Prefix for the autodetect constants defined in this class */
	private static final String CONSTANT_PREFIX_AUTODETECT = "AUTODETECT_";


	/** Constants instance for this class */
	private static final Constants constants = new Constants(MBeanExporter.class);

	/** The beans to be exposed as JMX managed resources, with JMX names as keys */
	@Nullable
	private Map<String, Object> beans;

	/** The autodetect mode to use for this MBeanExporter */
	@Nullable
	private Integer autodetectMode;

	/** Whether to eagerly initialize candidate beans when autodetecting MBeans */
	private boolean allowEagerInit = false;

	/** Stores the MBeanInfoAssembler to use for this exporter */
	private MBeanInfoAssembler assembler = new SimpleReflectiveMBeanInfoAssembler();

	/** The strategy to use for creating ObjectNames for an object */
	private ObjectNamingStrategy namingStrategy = new KeyNamingStrategy();

	/** Indicates whether Spring should modify generated ObjectNames */
	private boolean ensureUniqueRuntimeObjectNames = true;

	/** Indicates whether Spring should expose the managed resource ClassLoader in the MBean */
	private boolean exposeManagedResourceClassLoader = true;

	/** A set of bean names that should be excluded from autodetection */
	private Set<String> excludedBeans = new HashSet<>();

	/** The MBeanExporterListeners registered with this exporter. */
	@Nullable
	private MBeanExporterListener[] listeners;

	/** The NotificationListeners to register for the MBeans registered by this exporter */
	@Nullable
	private NotificationListenerBean[] notificationListeners;

	/** Map of actually registered NotificationListeners */
	private final Map<NotificationListenerBean, ObjectName[]> registeredNotificationListeners = new LinkedHashMap<>();

	/** Stores the ClassLoader to use for generating lazy-init proxies */
	@Nullable
	private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();

	/** Stores the BeanFactory for use in autodetection process */
	@Nullable
	private ListableBeanFactory beanFactory;


	/**
	 * Supply a {@code Map} of beans to be registered with the JMX
	 * {@code MBeanServer}.
	 * <p>The String keys are the basis for the creation of JMX object names.
	 * By default, a JMX {@code ObjectName} will be created straight
	 * from the given key. This can be customized through specifying a
	 * custom {@code NamingStrategy}.
	 * <p>Both bean instances and bean names are allowed as values.
	 * Bean instances are typically linked in through bean references.
	 * Bean names will be resolved as beans in the current factory, respecting
	 * lazy-init markers (that is, not triggering initialization of such beans).
	 * @param beans a Map with JMX names as keys and bean instances or bean names
	 * as values
	 * @see #setNamingStrategy
	 * @see org.springframework.jmx.export.naming.KeyNamingStrategy
	 * @see javax.management.ObjectName#ObjectName(String)
	 */
	public void setBeans(Map<String, Object> beans) {
		this.beans = beans;
	}

	/**
	 * Set whether to autodetect MBeans in the bean factory that this exporter
	 * runs in. Will also ask an {@code AutodetectCapableMBeanInfoAssembler}
	 * if available.
	 * <p>This feature is turned off by default. Explicitly specify
	 * {@code true} here to enable autodetection.
	 * @see #setAssembler
	 * @see AutodetectCapableMBeanInfoAssembler
	 * @see #isMBean
	 */
	public void setAutodetect(boolean autodetect) {
		this.autodetectMode = (autodetect ? AUTODETECT_ALL : AUTODETECT_NONE);
	}

	/**
	 * Set the autodetection mode to use.
	 * @throws IllegalArgumentException if the supplied value is not
	 * one of the {@code AUTODETECT_} constants
	 * @see #setAutodetectModeName(String)
	 * @see #AUTODETECT_ALL
	 * @see #AUTODETECT_ASSEMBLER
	 * @see #AUTODETECT_MBEAN
	 * @see #AUTODETECT_NONE
	 */
	public void setAutodetectMode(int autodetectMode) {
		if (!constants.getValues(CONSTANT_PREFIX_AUTODETECT).contains(autodetectMode)) {
			throw new IllegalArgumentException("Only values of autodetect constants allowed");
		}
		this.autodetectMode = autodetectMode;
	}

	/**
	 * Set the autodetection mode to use by name.
	 * @throws IllegalArgumentException if the supplied value is not resolvable
	 * to one of the {@code AUTODETECT_} constants or is {@code null}
	 * @see #setAutodetectMode(int)
	 * @see #AUTODETECT_ALL
	 * @see #AUTODETECT_ASSEMBLER
	 * @see #AUTODETECT_MBEAN
	 * @see #AUTODETECT_NONE
	 */
	public void setAutodetectModeName(String constantName) {
		if (!constantName.startsWith(CONSTANT_PREFIX_AUTODETECT)) {
			throw new IllegalArgumentException("Only autodetect constants allowed");
		}
		this.autodetectMode = (Integer) constants.asNumber(constantName);
	}

	/**
	 * Specify whether to allow eager initialization of candidate beans
	 * when autodetecting MBeans in the Spring application context.
	 * <p>Default is "false", respecting lazy-init flags on bean definitions.
	 * Switch this to "true" in order to search lazy-init beans as well,
	 * including FactoryBean-produced objects that haven't been initialized yet.
	 */
	public void setAllowEagerInit(boolean allowEagerInit) {
		this.allowEagerInit = allowEagerInit;
	}

	/**
	 * Set the implementation of the {@code MBeanInfoAssembler} interface to use
	 * for this exporter. Default is a {@code SimpleReflectiveMBeanInfoAssembler}.
	 * <p>The passed-in assembler can optionally implement the
	 * {@code AutodetectCapableMBeanInfoAssembler} interface, which enables it
	 * to participate in the exporter's MBean autodetection process.
	 * @see org.springframework.jmx.export.assembler.SimpleReflectiveMBeanInfoAssembler
	 * @see org.springframework.jmx.export.assembler.AutodetectCapableMBeanInfoAssembler
	 * @see org.springframework.jmx.export.assembler.MetadataMBeanInfoAssembler
	 * @see #setAutodetect
	 */
	public void setAssembler(MBeanInfoAssembler assembler) {
		this.assembler = assembler;
	}

	/**
	 * Set the implementation of the {@code ObjectNamingStrategy} interface
	 * to use for this exporter. Default is a {@code KeyNamingStrategy}.
	 * @see org.springframework.jmx.export.naming.KeyNamingStrategy
	 * @see org.springframework.jmx.export.naming.MetadataNamingStrategy
	 */
	public void setNamingStrategy(ObjectNamingStrategy namingStrategy) {
		this.namingStrategy = namingStrategy;
	}

	/**
	 * Indicates whether Spring should ensure that {@link ObjectName ObjectNames}
	 * generated by the configured {@link ObjectNamingStrategy} for
	 * runtime-registered MBeans ({@link #registerManagedResource}) should get
	 * modified: to ensure uniqueness for every instance of a managed {@code Class}.
	 * <p>The default value is {@code true}.
	 * @see #registerManagedResource
	 * @see JmxUtils#appendIdentityToObjectName(javax.management.ObjectName, Object)
	 */
	public void setEnsureUniqueRuntimeObjectNames(boolean ensureUniqueRuntimeObjectNames) {
		this.ensureUniqueRuntimeObjectNames = ensureUniqueRuntimeObjectNames;
	}

	/**
	 * Indicates whether or not the managed resource should be exposed on the
	 * {@link Thread#getContextClassLoader() thread context ClassLoader} before
	 * allowing any invocations on the MBean to occur.
	 * <p>The default value is {@code true}, exposing a {@link SpringModelMBean}
	 * which performs thread context ClassLoader management. Switch this flag off to
	 * expose a standard JMX {@link javax.management.modelmbean.RequiredModelMBean}.
	 */
	public void setExposeManagedResourceClassLoader(boolean exposeManagedResourceClassLoader) {
		this.exposeManagedResourceClassLoader = exposeManagedResourceClassLoader;
	}

	/**
	 * Set the list of names for beans that should be excluded from autodetection.
	 */
	public void setExcludedBeans(String... excludedBeans) {
		this.excludedBeans.clear();
		Collections.addAll(this.excludedBeans, excludedBeans);
	}

	/**
	 * Add the name of bean that should be excluded from autodetection.
	 */
	public void addExcludedBean(String excludedBean) {
		Assert.notNull(excludedBean, "ExcludedBean must not be null");
		this.excludedBeans.add(excludedBean);
	}

	/**
	 * Set the {@code MBeanExporterListener}s that should be notified
	 * of MBean registration and unregistration events.
	 * @see MBeanExporterListener
	 */
	public void setListeners(MBeanExporterListener... listeners) {
		this.listeners = listeners;
	}

	/**
	 * Set the {@link NotificationListenerBean NotificationListenerBeans}
	 * containing the
	 * {@link javax.management.NotificationListener NotificationListeners}
	 * that will be registered with the {@link MBeanServer}.
	 * @see #setNotificationListenerMappings(java.util.Map)
	 * @see NotificationListenerBean
	 */
	public void setNotificationListeners(NotificationListenerBean... notificationListeners) {
		this.notificationListeners = notificationListeners;
	}

	/**
	 * Set the {@link NotificationListener NotificationListeners} to register
	 * with the {@link javax.management.MBeanServer}.
	 * <P>The key of each entry in the {@code Map} is a {@link String}
	 * representation of the {@link javax.management.ObjectName} or the bean
	 * name of the MBean the listener should be registered for. Specifying an
	 * asterisk ({@code *}) for a key will cause the listener to be
	 * associated with all MBeans registered by this class at startup time.
	 * <p>The value of each entry is the
	 * {@link javax.management.NotificationListener} to register. For more
	 * advanced options such as registering
	 * {@link javax.management.NotificationFilter NotificationFilters} and
	 * handback objects see {@link #setNotificationListeners(NotificationListenerBean[])}.
	 */
	public void setNotificationListenerMappings(Map<?, ? extends NotificationListener> listeners) {
		Assert.notNull(listeners, "'listeners' must not be null");
		List<NotificationListenerBean> notificationListeners =
				new ArrayList<>(listeners.size());

		listeners.forEach((key, listener) -> {
			// Get the listener from the map value.
			NotificationListenerBean bean = new NotificationListenerBean(listener);
			// Get the ObjectName from the map key.
			if (key != null && !WILDCARD.equals(key)) {
				// This listener is mapped to a specific ObjectName.
				bean.setMappedObjectName(key);
			}
			notificationListeners.add(bean);
		});

		this.notificationListeners = notificationListeners.toArray(new NotificationListenerBean[0]);
	}

	@Override
	public void setBeanClassLoader(ClassLoader classLoader) {
		this.beanClassLoader = classLoader;
	}

	/**
	 * This callback is only required for resolution of bean names in the
	 * {@link #setBeans(java.util.Map) "beans"} {@link Map} and for
	 * autodetection of MBeans (in the latter case, a
	 * {@code ListableBeanFactory} is required).
	 * @see #setBeans
	 * @see #setAutodetect
	 */
	@Override
	public void setBeanFactory(BeanFactory beanFactory) {
		if (beanFactory instanceof ListableBeanFactory) {
			this.beanFactory = (ListableBeanFactory) beanFactory;
		}
		else {
			logger.info("MBeanExporter not running in a ListableBeanFactory: autodetection of MBeans not available.");
		}
	}


	//---------------------------------------------------------------------
	// Lifecycle in bean factory: automatically register/unregister beans
	//---------------------------------------------------------------------

	@Override
	public void afterPropertiesSet() {
		// If no server was provided then try to find one. This is useful in an environment
		// where there is already an MBeanServer loaded.
		if (this.server == null) {
			this.server = JmxUtils.locateMBeanServer();
		}
	}

	/**
	 * Kick off bean registration automatically after the regular singleton instantiation phase.
	 * @see #registerBeans()
	 */
	@Override
	public void afterSingletonsInstantiated() {
		try {
			logger.info("Registering beans for JMX exposure on startup");
			registerBeans();
			registerNotificationListeners();
		}
		catch (RuntimeException ex) {
			// Unregister beans already registered by this exporter.
			unregisterNotificationListeners();
			unregisterBeans();
			throw ex;
		}
	}

	/**
	 * Unregisters all beans that this exported has exposed via JMX
	 * when the enclosing {@code ApplicationContext} is destroyed.
	 */
	@Override
	public void destroy() {
		logger.info("Unregistering JMX-exposed beans on shutdown");
		unregisterNotificationListeners();
		unregisterBeans();
	}


	//---------------------------------------------------------------------
	// Implementation of MBeanExportOperations interface
	//---------------------------------------------------------------------

	@Override
	public ObjectName registerManagedResource(Object managedResource) throws MBeanExportException {
		Assert.notNull(managedResource, "Managed resource must not be null");
		ObjectName objectName;
		try {
			objectName = getObjectName(managedResource, null);
			if (this.ensureUniqueRuntimeObjectNames) {
				objectName = JmxUtils.appendIdentityToObjectName(objectName, managedResource);
			}
		}
		catch (Throwable ex) {
			throw new MBeanExportException("Unable to generate ObjectName for MBean [" + managedResource + "]", ex);
		}
		registerManagedResource(managedResource, objectName);
		return objectName;
	}

	@Override
	public void registerManagedResource(Object managedResource, ObjectName objectName) throws MBeanExportException {
		Assert.notNull(managedResource, "Managed resource must not be null");
		Assert.notNull(objectName, "ObjectName must not be null");
		try {
			if (isMBean(managedResource.getClass())) {
				doRegister(managedResource, objectName);
			}
			else {
				ModelMBean mbean = createAndConfigureMBean(managedResource, managedResource.getClass().getName());
				doRegister(mbean, objectName);
				injectNotificationPublisherIfNecessary(managedResource, mbean, objectName);
			}
		}
		catch (JMException ex) {
			throw new UnableToRegisterMBeanException(
					"Unable to register MBean [" + managedResource + "] with object name [" + objectName + "]", ex);
		}
	}

	@Override
	public void unregisterManagedResource(ObjectName objectName) {
		Assert.notNull(objectName, "ObjectName must not be null");
		doUnregister(objectName);
	}


	//---------------------------------------------------------------------
	// Exporter implementation
	//---------------------------------------------------------------------

	/**
	 * Register the defined beans with the {@link MBeanServer}.
	 * <p>Each bean is exposed to the {@code MBeanServer} via a
	 * {@code ModelMBean}. The actual implementation of the
	 * {@code ModelMBean} interface used depends on the implementation of
	 * the {@code ModelMBeanProvider} interface that is configured. By
	 * default the {@code RequiredModelMBean} class that is supplied with
	 * all JMX implementations is used.
	 * <p>The management interface produced for each bean is dependent on the
	 * {@code MBeanInfoAssembler} implementation being used. The
	 * {@code ObjectName} given to each bean is dependent on the
	 * implementation of the {@code ObjectNamingStrategy} interface being used.
	 */
	protected void registerBeans() {
		// The beans property may be null, for example if we are relying solely on autodetection.
		if (this.beans == null) {
			this.beans = new HashMap<>();
			// Use AUTODETECT_ALL as default in no beans specified explicitly.
			if (this.autodetectMode == null) {
				this.autodetectMode = AUTODETECT_ALL;
			}
		}

		// Perform autodetection, if desired.
		int mode = (this.autodetectMode != null ? this.autodetectMode : AUTODETECT_NONE);
		if (mode != AUTODETECT_NONE) {
			if (this.beanFactory == null) {
				throw new MBeanExportException("Cannot autodetect MBeans if not running in a BeanFactory");
			}
			if (mode == AUTODETECT_MBEAN || mode == AUTODETECT_ALL) {
				// Autodetect any beans that are already MBeans.
				logger.debug("Autodetecting user-defined JMX MBeans");
				autodetect(this.beans, (beanClass, beanName) -> isMBean(beanClass));
			}
			// Allow the assembler a chance to vote for bean inclusion.
			if ((mode == AUTODETECT_ASSEMBLER || mode == AUTODETECT_ALL) &&
					this.assembler instanceof AutodetectCapableMBeanInfoAssembler) {
				autodetect(this.beans, ((AutodetectCapableMBeanInfoAssembler) this.assembler)::includeBean);
			}
		}

		if (!this.beans.isEmpty()) {
			this.beans.forEach((beanName, instance) -> registerBeanNameOrInstance(instance, beanName));
		}
	}

	/**
	 * Return whether the specified bean definition should be considered as lazy-init.
	 * @param beanFactory the bean factory that is supposed to contain the bean definition
	 * @param beanName the name of the bean to check
	 * @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory#getBeanDefinition
	 * @see org.springframework.beans.factory.config.BeanDefinition#isLazyInit
	 */
	protected boolean isBeanDefinitionLazyInit(ListableBeanFactory beanFactory, String beanName) {
		return (beanFactory instanceof ConfigurableListableBeanFactory && beanFactory.containsBeanDefinition(beanName) &&
				((ConfigurableListableBeanFactory) beanFactory).getBeanDefinition(beanName).isLazyInit());
	}

	/**
	 * Register an individual bean with the {@link #setServer MBeanServer}.
	 * <p>This method is responsible for deciding <strong>how</strong> a bean
	 * should be exposed to the {@code MBeanServer}. Specifically, if the
	 * supplied {@code mapValue} is the name of a bean that is configured
	 * for lazy initialization, then a proxy to the resource is registered with
	 * the {@code MBeanServer} so that the lazy load behavior is
	 * honored. If the bean is already an MBean then it will be registered
	 * directly with the {@code MBeanServer} without any intervention. For
	 * all other beans or bean names, the resource itself is registered with
	 * the {@code MBeanServer} directly.
	 * @param mapValue the value configured for this bean in the beans map;
	 * may be either the {@code String} name of a bean, or the bean itself
	 * @param beanKey the key associated with this bean in the beans map
	 * @return the {@code ObjectName} under which the resource was registered
	 * @throws MBeanExportException if the export failed
	 * @see #setBeans
	 * @see #registerBeanInstance
	 * @see #registerLazyInit
	 */
	protected ObjectName registerBeanNameOrInstance(Object mapValue, String beanKey) throws MBeanExportException {
		try {
			if (mapValue instanceof String) {
				// Bean name pointing to a potentially lazy-init bean in the factory.
				if (this.beanFactory == null) {
					throw new MBeanExportException("Cannot resolve bean names if not running in a BeanFactory");
				}
				String beanName = (String) mapValue;
				if (isBeanDefinitionLazyInit(this.beanFactory, beanName)) {
					ObjectName objectName = registerLazyInit(beanName, beanKey);
					replaceNotificationListenerBeanNameKeysIfNecessary(beanName, objectName);
					return objectName;
				}
				else {
					Object bean = this.beanFactory.getBean(beanName);
					ObjectName objectName = registerBeanInstance(bean, beanKey);
					replaceNotificationListenerBeanNameKeysIfNecessary(beanName, objectName);
					return objectName;
				}
			}
			else {
				// Plain bean instance -> register it directly.
				if (this.beanFactory != null) {
					Map<String, ?> beansOfSameType =
							this.beanFactory.getBeansOfType(mapValue.getClass(), false, this.allowEagerInit);
					for (Map.Entry<String, ?> entry : beansOfSameType.entrySet()) {
						if (entry.getValue() == mapValue) {
							String beanName = entry.getKey();
							ObjectName objectName = registerBeanInstance(mapValue, beanKey);
							replaceNotificationListenerBeanNameKeysIfNecessary(beanName, objectName);
							return objectName;
						}
					}
				}
				return registerBeanInstance(mapValue, beanKey);
			}
		}
		catch (Throwable ex) {
			throw new UnableToRegisterMBeanException(
					"Unable to register MBean [" + mapValue + "] with key '" + beanKey + "'", ex);
		}
	}

	/**
	 * Replace any bean names used as keys in the {@code NotificationListener}
	 * mappings with their corresponding {@code ObjectName} values.
	 * @param beanName the name of the bean to be registered
	 * @param objectName the {@code ObjectName} under which the bean will be registered
	 * with the {@code MBeanServer}
	 */
	private void replaceNotificationListenerBeanNameKeysIfNecessary(String beanName, ObjectName objectName) {
		if (this.notificationListeners != null) {
			for (NotificationListenerBean notificationListener : this.notificationListeners) {
				notificationListener.replaceObjectName(beanName, objectName);
			}
		}
	}

	/**
	 * Registers an existing MBean or an MBean adapter for a plain bean
	 * with the {@code MBeanServer}.
	 * @param bean the bean to register, either an MBean or a plain bean
	 * @param beanKey the key associated with this bean in the beans map
	 * @return the {@code ObjectName} under which the bean was registered
	 * with the {@code MBeanServer}
	 */
	private ObjectName registerBeanInstance(Object bean, String beanKey) throws JMException {
		ObjectName objectName = getObjectName(bean, beanKey);
		Object mbeanToExpose = null;
		if (isMBean(bean.getClass())) {
			mbeanToExpose = bean;
		}
		else {
			DynamicMBean adaptedBean = adaptMBeanIfPossible(bean);
			if (adaptedBean != null) {
				mbeanToExpose = adaptedBean;
			}
		}

		if (mbeanToExpose != null) {
			if (logger.isInfoEnabled()) {
				logger.info("Located MBean '" + beanKey + "': registering with JMX server as MBean [" +
						objectName + "]");
			}
			doRegister(mbeanToExpose, objectName);
		}
		else {
			if (logger.isInfoEnabled()) {
				logger.info("Located managed bean '" + beanKey + "': registering with JMX server as MBean [" +
						objectName + "]");
			}
			ModelMBean mbean = createAndConfigureMBean(bean, beanKey);
			doRegister(mbean, objectName);
			injectNotificationPublisherIfNecessary(bean, mbean, objectName);
		}

		return objectName;
	}

	/**
	 * Register beans that are configured for lazy initialization with the
	 * {@code MBeanServer} indirectly through a proxy.
	 * @param beanName the name of the bean in the {@code BeanFactory}
	 * @param beanKey the key associated with this bean in the beans map
	 * @return the {@code ObjectName} under which the bean was registered
	 * with the {@code MBeanServer}
	 */
	private ObjectName registerLazyInit(String beanName, String beanKey) throws JMException {
		Assert.state(this.beanFactory != null, "No BeanFactory set");

		ProxyFactory proxyFactory = new ProxyFactory();
		proxyFactory.setProxyTargetClass(true);
		proxyFactory.setFrozen(true);

		if (isMBean(this.beanFactory.getType(beanName))) {
			// A straight MBean... Let's create a simple lazy-init CGLIB proxy for it.
			LazyInitTargetSource targetSource = new LazyInitTargetSource();
			targetSource.setTargetBeanName(beanName);
			targetSource.setBeanFactory(this.beanFactory);
			proxyFactory.setTargetSource(targetSource);

			Object proxy = proxyFactory.getProxy(this.beanClassLoader);
			ObjectName objectName = getObjectName(proxy, beanKey);
			if (logger.isDebugEnabled()) {
				logger.debug("Located MBean '" + beanKey + "': registering with JMX server as lazy-init MBean [" +
						objectName + "]");
			}
			doRegister(proxy, objectName);
			return objectName;
		}

		else {
			// A simple bean... Let's create a lazy-init ModelMBean proxy with notification support.
			NotificationPublisherAwareLazyTargetSource targetSource = new NotificationPublisherAwareLazyTargetSource();
			targetSource.setTargetBeanName(beanName);
			targetSource.setBeanFactory(this.beanFactory);
			proxyFactory.setTargetSource(targetSource);

			Object proxy = proxyFactory.getProxy(this.beanClassLoader);
			ObjectName objectName = getObjectName(proxy, beanKey);
			if (logger.isDebugEnabled()) {
				logger.debug("Located simple bean '" + beanKey + "': registering with JMX server as lazy-init MBean [" +
						objectName + "]");
			}
			ModelMBean mbean = createAndConfigureMBean(proxy, beanKey);
			targetSource.setModelMBean(mbean);
			targetSource.setObjectName(objectName);
			doRegister(mbean, objectName);
			return objectName;
		}
	}

	/**
	 * Retrieve the {@code ObjectName} for a bean.
	 * <p>If the bean implements the {@code SelfNaming} interface, then the
	 * {@code ObjectName} will be retrieved using {@code SelfNaming.getObjectName()}.
	 * Otherwise, the configured {@code ObjectNamingStrategy} is used.
	 * @param bean the name of the bean in the {@code BeanFactory}
	 * @param beanKey the key associated with the bean in the beans map
	 * @return the {@code ObjectName} for the supplied bean
	 * @throws javax.management.MalformedObjectNameException
	 * if the retrieved {@code ObjectName} is malformed
	 */
	protected ObjectName getObjectName(Object bean, @Nullable String beanKey) throws MalformedObjectNameException {
		if (bean instanceof SelfNaming) {
			return ((SelfNaming) bean).getObjectName();
		}
		else {
			return this.namingStrategy.getObjectName(bean, beanKey);
		}
	}

	/**
	 * Determine whether the given bean class qualifies as an MBean as-is.
	 * <p>The default implementation delegates to {@link JmxUtils#isMBean},
	 * which checks for {@link javax.management.DynamicMBean} classes as well
	 * as classes with corresponding "*MBean" interface (Standard MBeans)
	 * or corresponding "*MXBean" interface (Java 6 MXBeans).
	 * @param beanClass the bean class to analyze
	 * @return whether the class qualifies as an MBean
	 * @see org.springframework.jmx.support.JmxUtils#isMBean(Class)
	 */
	protected boolean isMBean(@Nullable Class<?> beanClass) {
		return JmxUtils.isMBean(beanClass);
	}

	/**
	 * Build an adapted MBean for the given bean instance, if possible.
	 * <p>The default implementation builds a JMX 1.2 StandardMBean
	 * for the target's MBean/MXBean interface in case of an AOP proxy,
	 * delegating the interface's management operations to the proxy.
	 * @param bean the original bean instance
	 * @return the adapted MBean, or {@code null} if not possible
	 */
	@SuppressWarnings("unchecked")
	@Nullable
	protected DynamicMBean adaptMBeanIfPossible(Object bean) throws JMException {
		Class<?> targetClass = AopUtils.getTargetClass(bean);
		if (targetClass != bean.getClass()) {
			Class<?> ifc = JmxUtils.getMXBeanInterface(targetClass);
			if (ifc != null) {
				if (!ifc.isInstance(bean)) {
					throw new NotCompliantMBeanException("Managed bean [" + bean +
							"] has a target class with an MXBean interface but does not expose it in the proxy");
				}
				return new StandardMBean(bean, ((Class<Object>) ifc), true);
			}
			else {
				ifc = JmxUtils.getMBeanInterface(targetClass);
				if (ifc != null) {
					if (!ifc.isInstance(bean)) {
						throw new NotCompliantMBeanException("Managed bean [" + bean +
								"] has a target class with an MBean interface but does not expose it in the proxy");
					}
					return new StandardMBean(bean, ((Class<Object>) ifc));
				}
			}
		}
		return null;
	}

	/**
	 * Creates an MBean that is configured with the appropriate management
	 * interface for the supplied managed resource.
	 * @param managedResource the resource that is to be exported as an MBean
	 * @param beanKey the key associated with the managed bean
	 * @see #createModelMBean()
	 * @see #getMBeanInfo(Object, String)
	 */
	protected ModelMBean createAndConfigureMBean(Object managedResource, String beanKey)
			throws MBeanExportException {
		try {
			ModelMBean mbean = createModelMBean();
			mbean.setModelMBeanInfo(getMBeanInfo(managedResource, beanKey));
			mbean.setManagedResource(managedResource, MR_TYPE_OBJECT_REFERENCE);
			return mbean;
		}
		catch (Throwable ex) {
			throw new MBeanExportException("Could not create ModelMBean for managed resource [" +
					managedResource + "] with key '" + beanKey + "'", ex);
		}
	}

	/**
	 * Create an instance of a class that implements {@code ModelMBean}.
	 * <p>This method is called to obtain a {@code ModelMBean} instance to
	 * use when registering a bean. This method is called once per bean during the
	 * registration phase and must return a new instance of {@code ModelMBean}
	 * @return a new instance of a class that implements {@code ModelMBean}
	 * @throws javax.management.MBeanException if creation of the ModelMBean failed
	 */
	protected ModelMBean createModelMBean() throws MBeanException {
		return (this.exposeManagedResourceClassLoader ? new SpringModelMBean() : new RequiredModelMBean());
	}

	/**
	 * Gets the {@code ModelMBeanInfo} for the bean with the supplied key
	 * and of the supplied type.
	 */
	private ModelMBeanInfo getMBeanInfo(Object managedBean, String beanKey) throws JMException {
		ModelMBeanInfo info = this.assembler.getMBeanInfo(managedBean, beanKey);
		if (logger.isWarnEnabled() && ObjectUtils.isEmpty(info.getAttributes()) &&
				ObjectUtils.isEmpty(info.getOperations())) {
			logger.warn("Bean with key '" + beanKey +
					"' has been registered as an MBean but has no exposed attributes or operations");
		}
		return info;
	}


	//---------------------------------------------------------------------
	// Autodetection process
	//---------------------------------------------------------------------

	/**
	 * Performs the actual autodetection process, delegating to an
	 * {@code AutodetectCallback} instance to vote on the inclusion of a
	 * given bean.
	 * @param callback the {@code AutodetectCallback} to use when deciding
	 * whether to include a bean or not
	 */
	private void autodetect(Map<String, Object> beans, AutodetectCallback callback) {
		Assert.state(this.beanFactory != null, "No BeanFactory set");
		Set<String> beanNames = new LinkedHashSet<>(this.beanFactory.getBeanDefinitionCount());
		Collections.addAll(beanNames, this.beanFactory.getBeanDefinitionNames());
		if (this.beanFactory instanceof ConfigurableBeanFactory) {
			Collections.addAll(beanNames, ((ConfigurableBeanFactory) this.beanFactory).getSingletonNames());
		}

		for (String beanName : beanNames) {
			if (!isExcluded(beanName) && !isBeanDefinitionAbstract(this.beanFactory, beanName)) {
				try {
					Class<?> beanClass = this.beanFactory.getType(beanName);
					if (beanClass != null && callback.include(beanClass, beanName)) {
						boolean lazyInit = isBeanDefinitionLazyInit(this.beanFactory, beanName);
						Object beanInstance = null;
						if (!lazyInit) {
							beanInstance = this.beanFactory.getBean(beanName);
							if (!beanClass.isInstance(beanInstance)) {
								continue;
							}
						}
						if (!ScopedProxyUtils.isScopedTarget(beanName) && !beans.containsValue(beanName) &&
								(beanInstance == null ||
										!CollectionUtils.containsInstance(beans.values(), beanInstance))) {
							// Not already registered for JMX exposure.
							beans.put(beanName, (beanInstance != null ? beanInstance : beanName));
							if (logger.isInfoEnabled()) {
								logger.info("Bean with name '" + beanName + "' has been autodetected for JMX exposure");
							}
						}
						else {
							if (logger.isDebugEnabled()) {
								logger.debug("Bean with name '" + beanName + "' is already registered for JMX exposure");
							}
						}
					}
				}
				catch (CannotLoadBeanClassException ex) {
					if (this.allowEagerInit) {
						throw ex;
					}
					// otherwise ignore beans where the class is not resolvable
				}
			}
		}
	}

	/**
	 * Indicates whether or not a particular bean name is present in the excluded beans list.
	 */
	private boolean isExcluded(String beanName) {
		return (this.excludedBeans.contains(beanName) ||
					(beanName.startsWith(BeanFactory.FACTORY_BEAN_PREFIX) &&
							this.excludedBeans.contains(beanName.substring(BeanFactory.FACTORY_BEAN_PREFIX.length()))));
	}

	/**
	 * Return whether the specified bean definition should be considered as abstract.
	 */
	private boolean isBeanDefinitionAbstract(ListableBeanFactory beanFactory, String beanName) {
		return (beanFactory instanceof ConfigurableListableBeanFactory && beanFactory.containsBeanDefinition(beanName) &&
				((ConfigurableListableBeanFactory) beanFactory).getBeanDefinition(beanName).isAbstract());
	}


	//---------------------------------------------------------------------
	// Notification and listener management
	//---------------------------------------------------------------------

	/**
	 * If the supplied managed resource implements the {@link NotificationPublisherAware} an instance of
	 * {@link org.springframework.jmx.export.notification.NotificationPublisher} is injected.
	 */
	private void injectNotificationPublisherIfNecessary(
			Object managedResource, @Nullable ModelMBean modelMBean, @Nullable ObjectName objectName) {

		if (managedResource instanceof NotificationPublisherAware && modelMBean != null && objectName != null) {
			((NotificationPublisherAware) managedResource).setNotificationPublisher(
					new ModelMBeanNotificationPublisher(modelMBean, objectName, managedResource));
		}
	}

	/**
	 * Register the configured {@link NotificationListener NotificationListeners}
	 * with the {@link MBeanServer}.
	 */
	private void registerNotificationListeners() throws MBeanExportException {
		if (this.notificationListeners != null) {
			Assert.state(this.server != null, "No MBeanServer available");
			for (NotificationListenerBean bean : this.notificationListeners) {
				try {
					ObjectName[] mappedObjectNames = bean.getResolvedObjectNames();
					if (mappedObjectNames == null) {
						// Mapped to all MBeans registered by the MBeanExporter.
						mappedObjectNames = getRegisteredObjectNames();
					}
					if (this.registeredNotificationListeners.put(bean, mappedObjectNames) == null) {
						for (ObjectName mappedObjectName : mappedObjectNames) {
							this.server.addNotificationListener(mappedObjectName, bean.getNotificationListener(),
									bean.getNotificationFilter(), bean.getHandback());
						}
					}
				}
				catch (Throwable ex) {
					throw new MBeanExportException("Unable to register NotificationListener", ex);
				}
			}
		}
	}

	/**
	 * Unregister the configured {@link NotificationListener NotificationListeners}
	 * from the {@link MBeanServer}.
	 */
	private void unregisterNotificationListeners() {
		if (this.server != null) {
			this.registeredNotificationListeners.forEach((bean, mappedObjectNames) -> {
				for (ObjectName mappedObjectName : mappedObjectNames) {
					try {
						this.server.removeNotificationListener(mappedObjectName, bean.getNotificationListener(),
								bean.getNotificationFilter(), bean.getHandback());
					}
					catch (Throwable ex) {
						if (logger.isDebugEnabled()) {
							logger.debug("Unable to unregister NotificationListener", ex);
						}
					}
				}
			});
		}
		this.registeredNotificationListeners.clear();
	}

	/**
	 * Called when an MBean is registered. Notifies all registered
	 * {@link MBeanExporterListener MBeanExporterListeners} of the registration event.
	 * <p>Please note that if an {@link MBeanExporterListener} throws a (runtime)
	 * exception when notified, this will essentially interrupt the notification process
	 * and any remaining listeners that have yet to be notified will not (obviously)
	 * receive the {@link MBeanExporterListener#mbeanRegistered(javax.management.ObjectName)}
	 * callback.
	 * @param objectName the {@code ObjectName} of the registered MBean
	 */
	@Override
	protected void onRegister(ObjectName objectName) {
		notifyListenersOfRegistration(objectName);
	}

	/**
	 * Called when an MBean is unregistered. Notifies all registered
	 * {@link MBeanExporterListener MBeanExporterListeners} of the unregistration event.
	 * <p>Please note that if an {@link MBeanExporterListener} throws a (runtime)
	 * exception when notified, this will essentially interrupt the notification process
	 * and any remaining listeners that have yet to be notified will not (obviously)
	 * receive the {@link MBeanExporterListener#mbeanUnregistered(javax.management.ObjectName)}
	 * callback.
	 * @param objectName the {@code ObjectName} of the unregistered MBean
	 */
	@Override
	protected void onUnregister(ObjectName objectName) {
		notifyListenersOfUnregistration(objectName);
	}


	/**
	 * Notifies all registered {@link MBeanExporterListener MBeanExporterListeners} of the
	 * registration of the MBean identified by the supplied {@link ObjectName}.
	 */
	private void notifyListenersOfRegistration(ObjectName objectName) {
		if (this.listeners != null) {
			for (MBeanExporterListener listener : this.listeners) {
				listener.mbeanRegistered(objectName);
			}
		}
	}

	/**
	 * Notifies all registered {@link MBeanExporterListener MBeanExporterListeners} of the
	 * unregistration of the MBean identified by the supplied {@link ObjectName}.
	 */
	private void notifyListenersOfUnregistration(ObjectName objectName) {
		if (this.listeners != null) {
			for (MBeanExporterListener listener : this.listeners) {
				listener.mbeanUnregistered(objectName);
			}
		}
	}


	//---------------------------------------------------------------------
	// Inner classes for internal use
	//---------------------------------------------------------------------

	/**
	 * Internal callback interface for the autodetection process.
	 */
	@FunctionalInterface
	private interface AutodetectCallback {

		/**
		 * Called during the autodetection process to decide whether
		 * or not a bean should be included.
		 * @param beanClass the class of the bean
		 * @param beanName the name of the bean
		 */
		boolean include(Class<?> beanClass, String beanName);
	}


	/**
	 * Extension of {@link LazyInitTargetSource} that will inject a
	 * {@link org.springframework.jmx.export.notification.NotificationPublisher}
	 * into the lazy resource as it is created if required.
	 */
	@SuppressWarnings("serial")
	private class NotificationPublisherAwareLazyTargetSource extends LazyInitTargetSource {

		@Nullable
		private ModelMBean modelMBean;

		@Nullable
		private ObjectName objectName;

		public void setModelMBean(ModelMBean modelMBean) {
			this.modelMBean = modelMBean;
		}

		public void setObjectName(ObjectName objectName) {
			this.objectName = objectName;
		}

		@Override
		@Nullable
		public Object getTarget() {
			try {
				return super.getTarget();
			}
			catch (RuntimeException ex) {
				if (logger.isWarnEnabled()) {
					logger.warn("Failed to retrieve target for JMX-exposed bean [" + this.objectName + "]: " + ex);
				}
				throw ex;
			}
		}

		@Override
		protected void postProcessTargetObject(Object targetObject) {
			injectNotificationPublisherIfNecessary(targetObject, this.modelMBean, this.objectName);
		}
	}

}
