/*
 * 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.scheduling.quartz;

import java.io.IOException;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.Executor;
import javax.sql.DataSource;

import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.impl.RemoteScheduler;
import org.quartz.impl.SchedulerRepository;
import org.quartz.impl.StdSchedulerFactory;
import org.quartz.simpl.SimpleThreadPool;
import org.quartz.spi.JobFactory;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.SmartLifecycle;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.scheduling.SchedulingException;
import org.springframework.util.CollectionUtils;

/**
 * {@link FactoryBean} that creates and configures a Quartz {@link org.quartz.Scheduler},
 * manages its lifecycle as part of the Spring application context, and exposes the
 * Scheduler as bean reference for dependency injection.
 *
 * <p>Allows registration of JobDetails, Calendars and Triggers, automatically
 * starting the scheduler on initialization and shutting it down on destruction.
 * In scenarios that just require static registration of jobs at startup, there
 * is no need to access the Scheduler instance itself in application code.
 *
 * <p>For dynamic registration of jobs at runtime, use a bean reference to
 * this SchedulerFactoryBean to get direct access to the Quartz Scheduler
 * ({@code org.quartz.Scheduler}). This allows you to create new jobs
 * and triggers, and also to control and monitor the entire Scheduler.
 *
 * <p>Note that Quartz instantiates a new Job for each execution, in
 * contrast to Timer which uses a TimerTask instance that is shared
 * between repeated executions. Just JobDetail descriptors are shared.
 *
 * <p>When using persistent jobs, it is strongly recommended to perform all
 * operations on the Scheduler within Spring-managed (or plain JTA) transactions.
 * Else, database locking will not properly work and might even break.
 * (See {@link #setDataSource setDataSource} javadoc for details.)
 *
 * <p>The preferred way to achieve transactional execution is to demarcate
 * declarative transactions at the business facade level, which will
 * automatically apply to Scheduler operations performed within those scopes.
 * Alternatively, you may add transactional advice for the Scheduler itself.
 *
 * <p>Compatible with Quartz 2.1.4 and higher, as of Spring 4.1.
 *
 * @author Juergen Hoeller
 * @since 18.02.2004
 * @see #setDataSource
 * @see org.quartz.Scheduler
 * @see org.quartz.SchedulerFactory
 * @see org.quartz.impl.StdSchedulerFactory
 * @see org.springframework.transaction.interceptor.TransactionProxyFactoryBean
 */
public class SchedulerFactoryBean extends SchedulerAccessor implements FactoryBean<Scheduler>,
                BeanNameAware, ApplicationContextAware, InitializingBean, DisposableBean, SmartLifecycle {

        public static final String PROP_THREAD_COUNT = "org.quartz.threadPool.threadCount";

        public static final int DEFAULT_THREAD_COUNT = 10;


        private static final ThreadLocal<ResourceLoader> configTimeResourceLoaderHolder =
                        new ThreadLocal<ResourceLoader>();

        private static final ThreadLocal<Executor> configTimeTaskExecutorHolder =
                        new ThreadLocal<Executor>();

        private static final ThreadLocal<DataSource> configTimeDataSourceHolder =
                        new ThreadLocal<DataSource>();

        private static final ThreadLocal<DataSource> configTimeNonTransactionalDataSourceHolder =
                        new ThreadLocal<DataSource>();

        /**
         * Return the {@link ResourceLoader} for the currently configured Quartz Scheduler,
         * to be used by {@link ResourceLoaderClassLoadHelper}.
         * <p>This instance will be set before initialization of the corresponding Scheduler,
         * and reset immediately afterwards. It is thus only available during configuration.
         * @see #setApplicationContext
         * @see ResourceLoaderClassLoadHelper
         */
        public static ResourceLoader getConfigTimeResourceLoader() {
                return configTimeResourceLoaderHolder.get();
        }

        /**
         * Return the {@link Executor} for the currently configured Quartz Scheduler,
         * to be used by {@link LocalTaskExecutorThreadPool}.
         * <p>This instance will be set before initialization of the corresponding Scheduler,
         * and reset immediately afterwards. It is thus only available during configuration.
         * @since 2.0
         * @see #setTaskExecutor
         * @see LocalTaskExecutorThreadPool
         */
        public static Executor getConfigTimeTaskExecutor() {
                return configTimeTaskExecutorHolder.get();
        }

        /**
         * Return the {@link DataSource} for the currently configured Quartz Scheduler,
         * to be used by {@link LocalDataSourceJobStore}.
         * <p>This instance will be set before initialization of the corresponding Scheduler,
         * and reset immediately afterwards. It is thus only available during configuration.
         * @since 1.1
         * @see #setDataSource
         * @see LocalDataSourceJobStore
         */
        public static DataSource getConfigTimeDataSource() {
                return configTimeDataSourceHolder.get();
        }

        /**
         * Return the non-transactional {@link DataSource} for the currently configured
         * Quartz Scheduler, to be used by {@link LocalDataSourceJobStore}.
         * <p>This instance will be set before initialization of the corresponding Scheduler,
         * and reset immediately afterwards. It is thus only available during configuration.
         * @since 1.1
         * @see #setNonTransactionalDataSource
         * @see LocalDataSourceJobStore
         */
        public static DataSource getConfigTimeNonTransactionalDataSource() {
                return configTimeNonTransactionalDataSourceHolder.get();
        }


        private SchedulerFactory schedulerFactory;

        private Class<? extends SchedulerFactory> schedulerFactoryClass = StdSchedulerFactory.class;

        private String schedulerName;

        private Resource configLocation;

        private Properties quartzProperties;

        private Executor taskExecutor;

        private DataSource dataSource;

        private DataSource nonTransactionalDataSource;

    private Map<String, ?> schedulerContextMap;

        private ApplicationContext applicationContext;

        private String applicationContextSchedulerContextKey;

        private JobFactory jobFactory;

        private boolean jobFactorySet = false;

        private boolean autoStartup = true;

        private int startupDelay = 0;

        private int phase = Integer.MAX_VALUE;

        private boolean exposeSchedulerInRepository = false;

        private boolean waitForJobsToCompleteOnShutdown = false;

        private Scheduler scheduler;


        /**
         * Set an external Quartz {@link SchedulerFactory} instance to use.
         * <p>Default is an internal {@link StdSchedulerFactory} instance. If this method is
         * called, it overrides any class specified through {@link #setSchedulerFactoryClass}
         * as well as any settings specified through {@link #setConfigLocation},
         * {@link #setQuartzProperties}, {@link #setTaskExecutor} or {@link #setDataSource}.
         * <p><b>NOTE:</b> With an externally provided {@code SchedulerFactory} instance,
         * local settings such as {@link #setConfigLocation} or {@link #setQuartzProperties}
         * will be ignored here in {@code SchedulerFactoryBean}, expecting the external
         * {@code SchedulerFactory} instance to get initialized on its own.
         * @since 4.3.15
         * @see #setSchedulerFactoryClass
         */
        public void setSchedulerFactory(SchedulerFactory schedulerFactory) {
                this.schedulerFactory = schedulerFactory;
        }

        /**
         * Set the Quartz {@link SchedulerFactory} implementation to use.
         * <p>Default is the {@link StdSchedulerFactory} class, reading in the standard
         * {@code quartz.properties} from {@code quartz.jar}. For applying custom Quartz
         * properties, specify {@link #setConfigLocation "configLocation"} and/or
         * {@link #setQuartzProperties "quartzProperties"} etc on this local
         * {@code SchedulerFactoryBean} instance.
         * @see org.quartz.impl.StdSchedulerFactory
         * @see #setConfigLocation
         * @see #setQuartzProperties
         * @see #setTaskExecutor
         * @see #setDataSource
         */
        public void setSchedulerFactoryClass(Class<? extends SchedulerFactory> schedulerFactoryClass) {
                this.schedulerFactoryClass = schedulerFactoryClass;
        }

        /**
         * Set the name of the Scheduler to create via the SchedulerFactory.
         * <p>If not specified, the bean name will be used as default scheduler name.
         * @see #setBeanName
         * @see org.quartz.SchedulerFactory#getScheduler()
         * @see org.quartz.SchedulerFactory#getScheduler(String)
         */
        public void setSchedulerName(String schedulerName) {
                this.schedulerName = schedulerName;
        }

        /**
         * Set the location of the Quartz properties config file, for example
         * as classpath resource "classpath:quartz.properties".
         * <p>Note: Can be omitted when all necessary properties are specified
         * locally via this bean, or when relying on Quartz' default configuration.
         * @see #setQuartzProperties
         */
        public void setConfigLocation(Resource configLocation) {
                this.configLocation = configLocation;
        }

        /**
         * Set Quartz properties, like "org.quartz.threadPool.class".
         * <p>Can be used to override values in a Quartz properties config file,
         * or to specify all necessary properties locally.
         * @see #setConfigLocation
         */
        public void setQuartzProperties(Properties quartzProperties) {
                this.quartzProperties = quartzProperties;
        }

        /**
         * Set a Spring-managed {@link Executor} to use as Quartz backend.
         * Exposed as thread pool through the Quartz SPI.
         * <p>Can be used to assign a local JDK ThreadPoolExecutor or a CommonJ
         * WorkManager as Quartz backend, to avoid Quartz's manual thread creation.
         * <p>By default, a Quartz SimpleThreadPool will be used, configured through
         * the corresponding Quartz properties.
         * @since 2.0
         * @see #setQuartzProperties
         * @see LocalTaskExecutorThreadPool
         * @see org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor
         * @see org.springframework.scheduling.concurrent.DefaultManagedTaskExecutor
         */
        public void setTaskExecutor(Executor taskExecutor) {
                this.taskExecutor = taskExecutor;
        }

        /**
         * Set the default {@link DataSource} to be used by the Scheduler.
         * If set, this will override corresponding settings in Quartz properties.
         * <p>Note: If this is set, the Quartz settings should not define
         * a job store "dataSource" to avoid meaningless double configuration.
         * <p>A Spring-specific subclass of Quartz' JobStoreCMT will be used.
         * It is therefore strongly recommended to perform all operations on
         * the Scheduler within Spring-managed (or plain JTA) transactions.
         * Else, database locking will not properly work and might even break
         * (e.g. if trying to obtain a lock on Oracle without a transaction).
         * <p>Supports both transactional and non-transactional DataSource access.
         * With a non-XA DataSource and local Spring transactions, a single DataSource
         * argument is sufficient. In case of an XA DataSource and global JTA transactions,
         * SchedulerFactoryBean's "nonTransactionalDataSource" property should be set,
         * passing in a non-XA DataSource that will not participate in global transactions.
         * @since 1.1
         * @see #setNonTransactionalDataSource
         * @see #setQuartzProperties
         * @see #setTransactionManager
         * @see LocalDataSourceJobStore
         */
        public void setDataSource(DataSource dataSource) {
                this.dataSource = dataSource;
        }

        /**
         * Set the {@link DataSource} to be used <i>for non-transactional access</i>.
         * <p>This is only necessary if the default DataSource is an XA DataSource that will
         * always participate in transactions: A non-XA version of that DataSource should
         * be specified as "nonTransactionalDataSource" in such a scenario.
         * <p>This is not relevant with a local DataSource instance and Spring transactions.
         * Specifying a single default DataSource as "dataSource" is sufficient there.
         * @since 1.1
         * @see #setDataSource
         * @see LocalDataSourceJobStore
         */
        public void setNonTransactionalDataSource(DataSource nonTransactionalDataSource) {
                this.nonTransactionalDataSource = nonTransactionalDataSource;
        }

        /**
         * Register objects in the Scheduler context via a given Map.
         * These objects will be available to any Job that runs in this Scheduler.
         * <p>Note: When using persistent Jobs whose JobDetail will be kept in the
         * database, do not put Spring-managed beans or an ApplicationContext
         * reference into the JobDataMap but rather into the SchedulerContext.
         * @param schedulerContextAsMap a Map with String keys and any objects as
         * values (for example Spring-managed beans)
         * @see JobDetailFactoryBean#setJobDataAsMap
         */
        public void setSchedulerContextAsMap(Map<String, ?> schedulerContextAsMap) {
                this.schedulerContextMap = schedulerContextAsMap;
        }

        /**
         * Set the key of an {@link ApplicationContext} reference to expose in the
         * SchedulerContext, for example "applicationContext". Default is none.
         * Only applicable when running in a Spring ApplicationContext.
         * <p>Note: When using persistent Jobs whose JobDetail will be kept in the
         * database, do not put an ApplicationContext reference into the JobDataMap
         * but rather into the SchedulerContext.
         * <p>In case of a QuartzJobBean, the reference will be applied to the Job
         * instance as bean property. An "applicationContext" attribute will
         * correspond to a "setApplicationContext" method in that scenario.
         * <p>Note that BeanFactory callback interfaces like ApplicationContextAware
         * are not automatically applied to Quartz Job instances, because Quartz
         * itself is responsible for the lifecycle of its Jobs.
         * @see JobDetailFactoryBean#setApplicationContextJobDataKey
         * @see org.springframework.context.ApplicationContext
         */
        public void setApplicationContextSchedulerContextKey(String applicationContextSchedulerContextKey) {
                this.applicationContextSchedulerContextKey = applicationContextSchedulerContextKey;
        }

        /**
         * Set the Quartz {@link JobFactory} to use for this Scheduler.
         * <p>Default is Spring's {@link AdaptableJobFactory}, which supports
         * {@link java.lang.Runnable} objects as well as standard Quartz
         * {@link org.quartz.Job} instances. Note that this default only applies
         * to a <i>local</i> Scheduler, not to a RemoteScheduler (where setting
         * a custom JobFactory is not supported by Quartz).
         * <p>Specify an instance of Spring's {@link SpringBeanJobFactory} here
         * (typically as an inner bean definition) to automatically populate a job's
         * bean properties from the specified job data map and scheduler context.
         * @since 2.0
         * @see AdaptableJobFactory
         * @see SpringBeanJobFactory
         */
        public void setJobFactory(JobFactory jobFactory) {
                this.jobFactory = jobFactory;
                this.jobFactorySet = true;
        }

        /**
         * Set whether to automatically start the scheduler after initialization.
         * <p>Default is "true"; set this to "false" to allow for manual startup.
         */
        public void setAutoStartup(boolean autoStartup) {
                this.autoStartup = autoStartup;
        }

        /**
         * Return whether this scheduler is configured for auto-startup. If "true",
         * the scheduler will start after the context is refreshed and after the
         * start delay, if any.
         */
        @Override
        public boolean isAutoStartup() {
                return this.autoStartup;
        }

        /**
         * Specify the phase in which this scheduler should be started and stopped.
         * The startup order proceeds from lowest to highest, and the shutdown order
         * is the reverse of that. By default this value is {@code Integer.MAX_VALUE}
         * meaning that this scheduler starts as late as possible and stops as soon
         * as possible.
         * @since 3.0
         */
        public void setPhase(int phase) {
                this.phase = phase;
        }

        /**
         * Return the phase in which this scheduler will be started and stopped.
         */
        @Override
        public int getPhase() {
                return this.phase;
        }

        /**
         * Set the number of seconds to wait after initialization before
         * starting the scheduler asynchronously. Default is 0, meaning
         * immediate synchronous startup on initialization of this bean.
         * <p>Setting this to 10 or 20 seconds makes sense if no jobs
         * should be run before the entire application has started up.
         */
        public void setStartupDelay(int startupDelay) {
                this.startupDelay = startupDelay;
        }

        /**
         * Set whether to expose the Spring-managed {@link Scheduler} instance in the
         * Quartz {@link SchedulerRepository}. Default is "false", since the Spring-managed
         * Scheduler is usually exclusively intended for access within the Spring context.
         * <p>Switch this flag to "true" in order to expose the Scheduler globally.
         * This is not recommended unless you have an existing Spring application that
         * relies on this behavior. Note that such global exposure was the accidental
         * default in earlier Spring versions; this has been fixed as of Spring 2.5.6.
         */
        public void setExposeSchedulerInRepository(boolean exposeSchedulerInRepository) {
                this.exposeSchedulerInRepository = exposeSchedulerInRepository;
        }

        /**
         * Set whether to wait for running jobs to complete on shutdown.
         * <p>Default is "false". Switch this to "true" if you prefer
         * fully completed jobs at the expense of a longer shutdown phase.
         * @see org.quartz.Scheduler#shutdown(boolean)
         */
        public void setWaitForJobsToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown) {
                this.waitForJobsToCompleteOnShutdown = waitForJobsToCompleteOnShutdown;
        }

        @Override
        public void setBeanName(String name) {
                if (this.schedulerName == null) {
                        this.schedulerName = name;
                }
        }

        @Override
        public void setApplicationContext(ApplicationContext applicationContext) {
                this.applicationContext = applicationContext;
        }


        //---------------------------------------------------------------------
        // Implementation of InitializingBean interface
        //---------------------------------------------------------------------

        @Override
        public void afterPropertiesSet() throws Exception {
                if (this.dataSource == null && this.nonTransactionalDataSource != null) {
                        this.dataSource = this.nonTransactionalDataSource;
                }

                if (this.applicationContext != null && this.resourceLoader == null) {
                        this.resourceLoader = this.applicationContext;
                }

                // Initialize the Scheduler instance...
                this.scheduler = prepareScheduler(prepareSchedulerFactory());
                try {
                        registerListeners();
                        registerJobsAndTriggers();
                }
                catch (Exception ex) {
                        try {
                                this.scheduler.shutdown(true);
                        }
                        catch (Exception ex2) {
                                logger.debug("Scheduler shutdown exception after registration failure", ex2);
                        }
                        throw ex;
                }
        }


        /**
         * Create a SchedulerFactory if necessary and apply locally defined Quartz properties to it.
         * @return the initialized SchedulerFactory
         */
        private SchedulerFactory prepareSchedulerFactory() throws SchedulerException, IOException {
                SchedulerFactory schedulerFactory = this.schedulerFactory;
                if (schedulerFactory == null) {
                        // Create local SchedulerFactory instance (typically a StdSchedulerFactory)
                        schedulerFactory = BeanUtils.instantiateClass(this.schedulerFactoryClass);
                        if (schedulerFactory instanceof StdSchedulerFactory) {
                                initSchedulerFactory((StdSchedulerFactory) schedulerFactory);
                        }
                        else if (this.configLocation != null || this.quartzProperties != null ||
                                        this.taskExecutor != null || this.dataSource != null) {
                                throw new IllegalArgumentException(
                                                "StdSchedulerFactory required for applying Quartz properties: " + schedulerFactory);
                        }
                        // Otherwise, no local settings to be applied via StdSchedulerFactory.initialize(Properties)
                }
                // Otherwise, assume that externally provided factory has been initialized with appropriate settings
                return schedulerFactory;
        }

        /**
         * Initialize the given SchedulerFactory, applying locally defined Quartz properties to it.
         * @param schedulerFactory the SchedulerFactory to initialize
         */
        private void initSchedulerFactory(StdSchedulerFactory schedulerFactory) throws SchedulerException, IOException {
                Properties mergedProps = new Properties();
                if (this.resourceLoader != null) {
                        mergedProps.setProperty(StdSchedulerFactory.PROP_SCHED_CLASS_LOAD_HELPER_CLASS,
                                        ResourceLoaderClassLoadHelper.class.getName());
                }

                if (this.taskExecutor != null) {
                        mergedProps.setProperty(StdSchedulerFactory.PROP_THREAD_POOL_CLASS,
                                        LocalTaskExecutorThreadPool.class.getName());
                }
                else {
                        // Set necessary default properties here, as Quartz will not apply
                        // its default configuration when explicitly given properties.
                        mergedProps.setProperty(StdSchedulerFactory.PROP_THREAD_POOL_CLASS, SimpleThreadPool.class.getName());
                        mergedProps.setProperty(PROP_THREAD_COUNT, Integer.toString(DEFAULT_THREAD_COUNT));
                }

                if (this.configLocation != null) {
                        if (logger.isInfoEnabled()) {
                                logger.info("Loading Quartz config from [" + this.configLocation + "]");
                        }
                        PropertiesLoaderUtils.fillProperties(mergedProps, this.configLocation);
                }

                CollectionUtils.mergePropertiesIntoMap(this.quartzProperties, mergedProps);
                if (this.dataSource != null) {
                        mergedProps.put(StdSchedulerFactory.PROP_JOB_STORE_CLASS, LocalDataSourceJobStore.class.getName());
                }
                if (this.schedulerName != null) {
                        mergedProps.put(StdSchedulerFactory.PROP_SCHED_INSTANCE_NAME, this.schedulerName);
                }

                schedulerFactory.initialize(mergedProps);
        }

        private Scheduler prepareScheduler(SchedulerFactory schedulerFactory) throws SchedulerException {
                if (this.resourceLoader != null) {
                        // Make given ResourceLoader available for SchedulerFactory configuration.
                        configTimeResourceLoaderHolder.set(this.resourceLoader);
                }
                if (this.taskExecutor != null) {
                        // Make given TaskExecutor available for SchedulerFactory configuration.
                        configTimeTaskExecutorHolder.set(this.taskExecutor);
                }
                if (this.dataSource != null) {
                        // Make given DataSource available for SchedulerFactory configuration.
                        configTimeDataSourceHolder.set(this.dataSource);
                }
                if (this.nonTransactionalDataSource != null) {
                        // Make given non-transactional DataSource available for SchedulerFactory configuration.
                        configTimeNonTransactionalDataSourceHolder.set(this.nonTransactionalDataSource);
                }

                // Get Scheduler instance from SchedulerFactory.
                try {
                        Scheduler scheduler = createScheduler(schedulerFactory, this.schedulerName);
                        populateSchedulerContext(scheduler);

                        if (!this.jobFactorySet && !(scheduler instanceof RemoteScheduler)) {
                                // Use AdaptableJobFactory as default for a local Scheduler, unless when
                                // explicitly given a null value through the "jobFactory" bean property.
                                this.jobFactory = new AdaptableJobFactory();
                        }
                        if (this.jobFactory != null) {
                                if (this.jobFactory instanceof SchedulerContextAware) {
                                        ((SchedulerContextAware) this.jobFactory).setSchedulerContext(scheduler.getContext());
                                }
                                scheduler.setJobFactory(this.jobFactory);
                        }
                        return scheduler;
                }

                finally {
                        if (this.resourceLoader != null) {
                                configTimeResourceLoaderHolder.remove();
                        }
                        if (this.taskExecutor != null) {
                                configTimeTaskExecutorHolder.remove();
                        }
                        if (this.dataSource != null) {
                                configTimeDataSourceHolder.remove();
                        }
                        if (this.nonTransactionalDataSource != null) {
                                configTimeNonTransactionalDataSourceHolder.remove();
                        }
                }
        }

        /**
         * Create the Scheduler instance for the given factory and scheduler name.
         * Called by {@link #afterPropertiesSet}.
         * <p>The default implementation invokes SchedulerFactory's {@code getScheduler}
         * method. Can be overridden for custom Scheduler creation.
         * @param schedulerFactory the factory to create the Scheduler with
         * @param schedulerName the name of the scheduler to create
         * @return the Scheduler instance
         * @throws SchedulerException if thrown by Quartz methods
         * @see #afterPropertiesSet
         * @see org.quartz.SchedulerFactory#getScheduler
         */
        protected Scheduler createScheduler(SchedulerFactory schedulerFactory, String schedulerName)
                        throws SchedulerException {

                // Override thread context ClassLoader to work around naive Quartz ClassLoadHelper loading.
                Thread currentThread = Thread.currentThread();
                ClassLoader threadContextClassLoader = currentThread.getContextClassLoader();
                boolean overrideClassLoader = (this.resourceLoader != null &&
                                this.resourceLoader.getClassLoader() != threadContextClassLoader);
                if (overrideClassLoader) {
                        currentThread.setContextClassLoader(this.resourceLoader.getClassLoader());
                }
                try {
                        SchedulerRepository repository = SchedulerRepository.getInstance();
                        synchronized (repository) {
                                Scheduler existingScheduler = (schedulerName != null ? repository.lookup(schedulerName) : null);
                                Scheduler newScheduler = schedulerFactory.getScheduler();
                                if (newScheduler == existingScheduler) {
                                        throw new IllegalStateException("Active Scheduler of name '" + schedulerName + "' already registered " +
                                                        "in Quartz SchedulerRepository. Cannot create a new Spring-managed Scheduler of the same name!");
                                }
                                if (!this.exposeSchedulerInRepository) {
                                        // Need to remove it in this case, since Quartz shares the Scheduler instance by default!
                                        SchedulerRepository.getInstance().remove(newScheduler.getSchedulerName());
                                }
                                return newScheduler;
                        }
                }
                finally {
                        if (overrideClassLoader) {
                                // Reset original thread context ClassLoader.
                                currentThread.setContextClassLoader(threadContextClassLoader);
                        }
                }
        }

        /**
         * Expose the specified context attributes and/or the current
         * ApplicationContext in the Quartz SchedulerContext.
         */
        private void populateSchedulerContext(Scheduler scheduler) throws SchedulerException {
                // Put specified objects into Scheduler context.
                if (this.schedulerContextMap != null) {
                        scheduler.getContext().putAll(this.schedulerContextMap);
                }

                // Register ApplicationContext in Scheduler context.
                if (this.applicationContextSchedulerContextKey != null) {
                        if (this.applicationContext == null) {
                                throw new IllegalStateException(
                                        "SchedulerFactoryBean needs to be set up in an ApplicationContext " +
                                        "to be able to handle an 'applicationContextSchedulerContextKey'");
                        }
                        scheduler.getContext().put(this.applicationContextSchedulerContextKey, this.applicationContext);
                }
        }


        /**
         * Start the Quartz Scheduler, respecting the "startupDelay" setting.
         * @param scheduler the Scheduler to start
         * @param startupDelay the number of seconds to wait before starting
         * the Scheduler asynchronously
         */
        protected void startScheduler(final Scheduler scheduler, final int startupDelay) throws SchedulerException {
                if (startupDelay <= 0) {
                        logger.info("Starting Quartz Scheduler now");
                        scheduler.start();
                }
                else {
                        if (logger.isInfoEnabled()) {
                                logger.info("Will start Quartz Scheduler [" + scheduler.getSchedulerName() +
                                                "] in " + startupDelay + " seconds");
                        }
                        // Not using the Quartz startDelayed method since we explicitly want a daemon
                        // thread here, not keeping the JVM alive in case of all other threads ending.
                        Thread schedulerThread = new Thread() {
                                @Override
                                public void run() {
                                        try {
                                                Thread.sleep(startupDelay * 1000);
                                        }
                                        catch (InterruptedException ex) {
                                                Thread.currentThread().interrupt();
                                                // simply proceed
                                        }
                                        if (logger.isInfoEnabled()) {
                                                logger.info("Starting Quartz Scheduler now, after delay of " + startupDelay + " seconds");
                                        }
                                        try {
                                                scheduler.start();
                                        }
                                        catch (SchedulerException ex) {
                                                throw new SchedulingException("Could not start Quartz Scheduler after delay", ex);
                                        }
                                }
                        };
                        schedulerThread.setName("Quartz Scheduler [" + scheduler.getSchedulerName() + "]");
                        schedulerThread.setDaemon(true);
                        schedulerThread.start();
                }
        }


        //---------------------------------------------------------------------
        // Implementation of FactoryBean interface
        //---------------------------------------------------------------------

        @Override
        public Scheduler getScheduler() {
                return this.scheduler;
        }

        @Override
        public Scheduler getObject() {
                return this.scheduler;
        }

        @Override
        public Class<? extends Scheduler> getObjectType() {
                return (this.scheduler != null ? this.scheduler.getClass() : Scheduler.class);
        }

        @Override
        public boolean isSingleton() {
                return true;
        }


        //---------------------------------------------------------------------
        // Implementation of SmartLifecycle interface
        //---------------------------------------------------------------------

        @Override
        public void start() throws SchedulingException {
                if (this.scheduler != null) {
                        try {
                                startScheduler(this.scheduler, this.startupDelay);
                        }
                        catch (SchedulerException ex) {
                                throw new SchedulingException("Could not start Quartz Scheduler", ex);
                        }
                }
        }

        @Override
        public void stop() throws SchedulingException {
                if (this.scheduler != null) {
                        try {
                                this.scheduler.standby();
                        }
                        catch (SchedulerException ex) {
                                throw new SchedulingException("Could not stop Quartz Scheduler", ex);
                        }
                }
        }

        @Override
        public void stop(Runnable callback) throws SchedulingException {
                stop();
                callback.run();
        }

        @Override
        public boolean isRunning() throws SchedulingException {
                if (this.scheduler != null) {
                        try {
                                return !this.scheduler.isInStandbyMode();
                        }
                        catch (SchedulerException ex) {
                                return false;
                        }
                }
                return false;
        }


        //---------------------------------------------------------------------
        // Implementation of DisposableBean interface
        //---------------------------------------------------------------------

        /**
         * Shut down the Quartz scheduler on bean factory shutdown,
         * stopping all scheduled jobs.
         */
        @Override
        public void destroy() throws SchedulerException {
                if (this.scheduler != null) {
                        logger.info("Shutting down Quartz Scheduler");
                        this.scheduler.shutdown(this.waitForJobsToCompleteOnShutdown);
                }
        }

}