ContextIdApplicationContextInitializer Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/context/ContextIdApplicationContextInitializer.java lines 38–95

public class ContextIdApplicationContextInitializer
		implements ApplicationContextInitializer<ConfigurableApplicationContext>, Ordered {

	private int order = Ordered.LOWEST_PRECEDENCE - 10;

	public void setOrder(int order) {
		this.order = order;
	}

	@Override
	public int getOrder() {
		return this.order;
	}

	@Override
	public void initialize(ConfigurableApplicationContext applicationContext) {
		ContextId contextId = getContextId(applicationContext);
		applicationContext.setId(contextId.getId());
		applicationContext.getBeanFactory().registerSingleton(ContextId.class.getName(), contextId);
	}

	private ContextId getContextId(ConfigurableApplicationContext applicationContext) {
		ApplicationContext parent = applicationContext.getParent();
		if (parent != null && parent.containsBean(ContextId.class.getName())) {
			return parent.getBean(ContextId.class).createChildId();
		}
		return new ContextId(getApplicationId(applicationContext.getEnvironment()));
	}

	private String getApplicationId(ConfigurableEnvironment environment) {
		String name = environment.getProperty("spring.application.name");
		return StringUtils.hasText(name) ? name : "application";
	}

	/**
	 * The ID of a context.
	 */
	static class ContextId {

		private final AtomicLong children = new AtomicLong();

		private final String id;

		ContextId(String id) {
			this.id = id;
		}

		ContextId createChildId() {
			return new ContextId(this.id + "-" + this.children.incrementAndGet());
		}

		String getId() {
			return this.id;
		}

	}

}