RunListener Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java lines 1549–1569

		private static final class RunListener implements SpringApplicationRunListener, Running {

			private final List<ConfigurableApplicationContext> contexts = Collections
				.synchronizedList(new ArrayList<>());

			@Override
			public void contextLoaded(ConfigurableApplicationContext context) {
				this.contexts.add(context);
			}

			@Override
			public ConfigurableApplicationContext getApplicationContext() {
				List<ConfigurableApplicationContext> rootContexts = this.contexts.stream()
					.filter((context) -> context.getParent() == null)
					.toList();
				Assert.state(!rootContexts.isEmpty(), "No root application context located");
				Assert.state(rootContexts.size() == 1, "No unique root application context located");
				return rootContexts.get(0);
			}

		}