/**
 * 功能說明： 事件
 * <p>
 * Original @Author: steakliu-劉牌, 2023-03-30  11:02
 * <p>
 * Copyright (C)2020-2022  steakliu All rights reserved.
 */
public class AppEvent extends ApplicationEvent {
    private final String event;
    public AppEvent(Object source, String event) {
        super(source);
        this.event = event;
    }
    public String getEvent() {
        return event;
    }
}

/**
 * 功能說明：事件監(jiān)聽器
 * <p>
 * Original @Author: steakliu-劉牌, 2023-03-30  11:03
 * <p>
 * Copyright (C)2020-2022  steakliu All rights reserved.
 */
@Component
public class AppListener implements ApplicationListener<AppEvent> {
    @Override
    public void onApplicationEvent(AppEvent event) {
        System.out.println("event:  "+event.getEvent());
    }
}

/**
 * 功能說明：事件發(fā)布器
 * <p>
 * Original @Author: steakliu-劉牌, 2023-06-11  13:55
 * <p>
 * Copyright (C)2020-2022  steakliu All rights reserved.
 */
@Component
public class AppPublisher {
    @Resource
    private ApplicationEventPublisher applicationEventPublisher;
    public void publish(){
        applicationEventPublisher.publishEvent(new AppEvent(new AppListener(),"publish event"));
    }
}

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
        AppPublisher publisher = context.getBean(AppPublisher.class);
        publisher.publish();
    }
}

@Override
	public void refresh() throws BeansException, IllegalStateException {
		synchronized (this.startupShutdownMonitor) {
    // Initialize event multicaster for this context.
				initApplicationEventMulticaster();
				// Check for listener beans and register them.
				registerListeners();
				// Last step: publish corresponding event.
				finishRefresh();
			}
		}
	}

protected void initApplicationEventMulticaster() {
        ConfigurableListableBeanFactory beanFactory = getBeanFactory();
        if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {
            this.applicationEventMulticaster =
                    beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);
            if (logger.isTraceEnabled()) {
                logger.trace("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]");
            }
        } else {
            this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);
            beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);
            if (logger.isTraceEnabled()) {
                logger.trace("No '" + APPLICATION_EVENT_MULTICASTER_BEAN_NAME + "' bean, using " +
                        "[" + this.applicationEventMulticaster.getClass().getSimpleName() + "]");
            }
        }
    }

public final Set<String> applicationListenerBeans = new LinkedHashSet<>();

protected void publishEvent(Object event, @Nullable ResolvableType eventType) {
  getApplicationEventMulticaster().multicastEvent(applicationEvent, eventType);
}

public void multicastEvent(ApplicationEvent event, @Nullable ResolvableType eventType) {
        ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event));
        Executor executor = getTaskExecutor();
        for (ApplicationListener<?> listener : getApplicationListeners(event, type)) {
            if (executor != null) {
                executor.execute(() -> invokeListener(listener, event));
            } else {
                invokeListener(listener, event);
            }
        }
    }

/**
 * 功能說明： 事件任務(wù)線程池
 * <p>
 * Original @Author: steakliu-劉牌, 2023-06-11  13:17
 * <p>
 * Copyright (C)2020-2022  steakliu All rights reserved.
 */
@Configuration
public class TaskExecutor {
    @Bean("eventTaskExecutor")
    public Executor taskExecutor() {
        ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
        threadPoolTaskExecutor.setCorePoolSize(10);
        threadPoolTaskExecutor.setMaxPoolSize(20);
        threadPoolTaskExecutor.setKeepAliveSeconds(10);
        threadPoolTaskExecutor.setThreadNamePrefix("application-event-thread");
        threadPoolTaskExecutor.setQueueCapacity(100);
        threadPoolTaskExecutor.setAllowCoreThreadTimeOut(true);
        threadPoolTaskExecutor.setAllowCoreThreadTimeOut(true);
        threadPoolTaskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.DiscardOldestPolicy());
        threadPoolTaskExecutor.initialize();
        return threadPoolTaskExecutor;
    }
    @Bean
    public ApplicationEventMulticaster applicationEventMulticaster() {
        SimpleApplicationEventMulticaster simpleApplicationEventMulticaster = new SimpleApplicationEventMulticaster();
        simpleApplicationEventMulticaster.setTaskExecutor(taskExecutor());
        return simpleApplicationEventMulticaster;
    }
}

private void doInvokeListener(ApplicationListener listener, ApplicationEvent event) {
		 listener.onApplicationEvent(event);
}