ApplicationContextClosedListener Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/SpringApplicationShutdownHook.java lines 242–259

	private final class ApplicationContextClosedListener implements ApplicationListener<ContextClosedEvent> {

		@Override
		public void onApplicationEvent(ContextClosedEvent event) {
			// The ContextClosedEvent is fired at the start of a call to {@code close()}
			// and if that happens in a different thread then the context may still be
			// active. Rather than just removing the context, we add it to a {@code
			// closedContexts} set. This is weak set so that the context can be GC'd once
			// the {@code close()} method returns.
			synchronized (SpringApplicationShutdownHook.class) {
				ApplicationContext applicationContext = event.getApplicationContext();
				SpringApplicationShutdownHook.this.contexts.remove(applicationContext);
				SpringApplicationShutdownHook.this.closedContexts
					.add((ConfigurableApplicationContext) applicationContext);
			}
		}

	}