EventPublishingRunListener Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/context/event/EventPublishingRunListener.java lines 55–155

class EventPublishingRunListener implements SpringApplicationRunListener, Ordered {

	private final SpringApplication application;

	private final String[] args;

	private final SimpleApplicationEventMulticaster initialMulticaster;

	EventPublishingRunListener(SpringApplication application, String[] args) {
		this.application = application;
		this.args = args;
		this.initialMulticaster = new SimpleApplicationEventMulticaster();
	}

	@Override
	public int getOrder() {
		return 0;
	}

	@Override
	public void starting(ConfigurableBootstrapContext bootstrapContext) {
		multicastInitialEvent(new ApplicationStartingEvent(bootstrapContext, this.application, this.args));
	}

	@Override
	public void environmentPrepared(ConfigurableBootstrapContext bootstrapContext,
			ConfigurableEnvironment environment) {
		multicastInitialEvent(
				new ApplicationEnvironmentPreparedEvent(bootstrapContext, this.application, this.args, environment));
	}

	@Override
	public void contextPrepared(ConfigurableApplicationContext context) {
		multicastInitialEvent(new ApplicationContextInitializedEvent(this.application, this.args, context));
	}

	@Override
	public void contextLoaded(ConfigurableApplicationContext context) {
		for (ApplicationListener<?> listener : this.application.getListeners()) {
			if (listener instanceof ApplicationContextAware contextAware) {
				contextAware.setApplicationContext(context);
			}
			context.addApplicationListener(listener);
		}
		multicastInitialEvent(new ApplicationPreparedEvent(this.application, this.args, context));
	}

	@Override
	public void started(ConfigurableApplicationContext context, @Nullable Duration timeTaken) {
		context.publishEvent(new ApplicationStartedEvent(this.application, this.args, context, timeTaken));
		AvailabilityChangeEvent.publish(context, LivenessState.CORRECT);
	}

	@Override
	public void ready(ConfigurableApplicationContext context, @Nullable Duration timeTaken) {
		context.publishEvent(new ApplicationReadyEvent(this.application, this.args, context, timeTaken));
		AvailabilityChangeEvent.publish(context, ReadinessState.ACCEPTING_TRAFFIC);
	}

	@Override
	public void failed(@Nullable ConfigurableApplicationContext context, Throwable exception) {
		ApplicationFailedEvent event = new ApplicationFailedEvent(this.application, this.args, context, exception);
		if (context != null && context.isActive()) {
			// Listeners have been registered to the application context so we should
			// use it at this point if we can
			context.publishEvent(event);
		}
		else {
			// An inactive context may not have a multicaster so we use our multicaster to
			// call all the context's listeners instead
			if (context instanceof AbstractApplicationContext abstractApplicationContext) {
				for (ApplicationListener<?> listener : abstractApplicationContext.getApplicationListeners()) {
					this.initialMulticaster.addApplicationListener(listener);
				}
			}
			this.initialMulticaster.setErrorHandler(new LoggingErrorHandler());
			this.initialMulticaster.multicastEvent(event);
		}
	}

	private void multicastInitialEvent(ApplicationEvent event) {
		refreshApplicationListeners();
		this.initialMulticaster.multicastEvent(event);
	}

	private void refreshApplicationListeners() {
		this.application.getListeners().forEach(this.initialMulticaster::addApplicationListener);
	}

	private static final class LoggingErrorHandler implements ErrorHandler {

		private static final Log logger = LogFactory.getLog(EventPublishingRunListener.class);

		@Override
		public void handleError(Throwable throwable) {
			logger.warn("Error calling ApplicationEventListener", throwable);
		}

	}

}