Spring : @EnableScheduling 的工作原理 找到带某个注解的方法MethodIntrospector.selectMethods进行代理

Spring : @EnableScheduling 的工作原理

https://blog.csdn.net/andy_zhang2007/article/details/96612243

spring task 通过@EnableScheduling启动流程简析

https://blog.csdn.net/u012881904/article/details/79996826

import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.beans.factory.SmartInitializingSingleton;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor;
import org.springframework.beans.factory.config.NamedBeanHolder;
import org.springframework.beans.factory.support.MergedBeanDefinitionPostProcessor;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.EmbeddedValueResolverAware;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.core.MethodIntrospector;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.core.annotation.AnnotationAwareOrderComparator;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.lang.Nullable;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.config.CronTask;
import org.springframework.scheduling.config.FixedDelayTask;
import org.springframework.scheduling.config.FixedRateTask;
import org.springframework.scheduling.config.ScheduledTask;
import org.springframework.scheduling.config.ScheduledTaskHolder;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.scheduling.support.ScheduledMethodRunnable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.util.StringValueResolver;

/**
 * Bean post-processor that registers methods annotated with @{@link Scheduled}
 * to be invoked by a {@link org.springframework.scheduling.TaskScheduler} according
 * to the "fixedRate", "fixedDelay", or "cron" expression provided via the annotation.
 *
 * <p>This post-processor is automatically registered by Spring's
 * {@code <task:annotation-driven>} XML element, and also by the
 * {@link EnableScheduling @EnableScheduling} annotation.
 *
 * <p>Autodetects any {@link SchedulingConfigurer} instances in the container,
 * allowing for customization of the scheduler to be used or for fine-grained
 * control over task registration (e.g. registration of {@link Trigger} tasks.
 * See the @{@link EnableScheduling} javadocs for complete usage details.
 *
 * @author Mark Fisher
 * @author Juergen Hoeller
 * @author Chris Beams
 * @author Elizabeth Chatman
 * @since 3.0
 * @see Scheduled
 * @see EnableScheduling
 * @see SchedulingConfigurer
 * @see org.springframework.scheduling.TaskScheduler
 * @see org.springframework.scheduling.config.ScheduledTaskRegistrar
 * @see AsyncAnnotationBeanPostProcessor
 */
public class ScheduledAnnotationBeanPostProcessor
        implements ScheduledTaskHolder, MergedBeanDefinitionPostProcessor, DestructionAwareBeanPostProcessor,
        Ordered, EmbeddedValueResolverAware, BeanNameAware, BeanFactoryAware, ApplicationContextAware,
        SmartInitializingSingleton, ApplicationListener<ContextRefreshedEvent>, DisposableBean {

public Object postProcessAfterInitialization(Object bean, String beanName) {
        if (bean instanceof AopInfrastructureBean || bean instanceof TaskScheduler ||
                bean instanceof ScheduledExecutorService) {
            // Ignore AOP infrastructure such as scoped proxies.
            return bean;
        }

        Class<?> targetClass = AopProxyUtils.ultimateTargetClass(bean);
        if (!this.nonAnnotatedClasses.contains(targetClass) &&
                AnnotationUtils.isCandidateClass(targetClass, Arrays.asList(Scheduled.class, Schedules.class))) {
            Map<Method, Set<Scheduled>> annotatedMethods = MethodIntrospector.selectMethods(targetClass,
                    (MethodIntrospector.MetadataLookup<Set<Scheduled>>) method -> {
                        Set<Scheduled> scheduledMethods = AnnotatedElementUtils.getMergedRepeatableAnnotations(
                                method, Scheduled.class, Schedules.class);
                        return (!scheduledMethods.isEmpty() ? scheduledMethods : null);
                    });
            if (annotatedMethods.isEmpty()) {
                this.nonAnnotatedClasses.add(targetClass);
                if (logger.isTraceEnabled()) {
                    logger.trace("No @Scheduled annotations found on bean class: " + targetClass);
                }
            }
            else {
                // Non-empty set of methods
                annotatedMethods.forEach((method, scheduledMethods) ->
                        scheduledMethods.forEach(scheduled -> processScheduled(scheduled, method, bean)));
                if (logger.isTraceEnabled()) {
                    logger.trace(annotatedMethods.size() + " @Scheduled methods processed on bean '" + beanName +
                            "': " + annotatedMethods);
                }
            }
        }
        return bean;
    }