/*
 * 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.debug("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.debug("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.debug("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.isDebugEnabled()) {
                                logger.debug("Located MBean '" + beanKey + "': registering with JMX server as MBean [" +
                                                objectName + "]");
                        }
                        doRegister(mbeanToExpose, objectName);
                }
                else {
                        if (logger.isDebugEnabled()) {
                                logger.debug("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.isInfoEnabled() && ObjectUtils.isEmpty(info.getAttributes()) &&
                                ObjectUtils.isEmpty(info.getOperations())) {
                        logger.info("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.isDebugEnabled()) {
                                                                logger.debug("Bean with name '" + beanName + "' has been autodetected for JMX exposure");
                                                        }
                                                }
                                                else {
                                                        if (logger.isTraceEnabled()) {
                                                                logger.trace("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.isInfoEnabled()) {
                                        logger.info("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);
                }
        }

}