ApplicationContextFactory Type — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/ApplicationContextFactory.java lines 38–103

@FunctionalInterface
public interface ApplicationContextFactory {

	/**
	 * A default {@link ApplicationContextFactory} implementation that will create an
	 * appropriate context for the {@link WebApplicationType}.
	 */
	ApplicationContextFactory DEFAULT = new DefaultApplicationContextFactory();

	/**
	 * Return the {@link Environment} type expected to be set on the
	 * {@link #create(WebApplicationType) created} application context. The result of this
	 * method can be used to convert an existing environment instance to the correct type.
	 * @param webApplicationType the web application type or {@code null}
	 * @return the expected application context type or {@code null} to use the default
	 * @since 2.6.14
	 */
	default @Nullable Class<? extends ConfigurableEnvironment> getEnvironmentType(
			@Nullable WebApplicationType webApplicationType) {
		return null;
	}

	/**
	 * Create a new {@link Environment} to be set on the
	 * {@link #create(WebApplicationType) created} application context. The result of this
	 * method must match the type returned by
	 * {@link #getEnvironmentType(WebApplicationType)}.
	 * @param webApplicationType the web application type or {@code null}
	 * @return an environment instance or {@code null} to use the default
	 * @since 2.6.14
	 */
	default @Nullable ConfigurableEnvironment createEnvironment(@Nullable WebApplicationType webApplicationType) {
		return null;
	}

	/**
	 * Creates the {@link ConfigurableApplicationContext application context} for a
	 * {@link SpringApplication}, respecting the given {@code webApplicationType}.
	 * @param webApplicationType the web application type
	 * @return the newly created application context
	 */
	@Nullable ConfigurableApplicationContext create(@Nullable WebApplicationType webApplicationType);

	/**
	 * Creates an {@code ApplicationContextFactory} that will create contexts by
	 * instantiating the given {@code contextClass} through its primary constructor.
	 * @param contextClass the context class
	 * @return the factory that will instantiate the context class
	 * @see BeanUtils#instantiateClass(Class)
	 */
	static ApplicationContextFactory ofContextClass(Class<? extends ConfigurableApplicationContext> contextClass) {
		return of(() -> BeanUtils.instantiateClass(contextClass));
	}

	/**
	 * Creates an {@code ApplicationContextFactory} that will create contexts by calling
	 * the given {@link Supplier}.
	 * @param supplier the context supplier, for example
	 * {@code AnnotationConfigApplicationContext::new}
	 * @return the factory that will instantiate the context class
	 */
	static ApplicationContextFactory of(Supplier<ConfigurableApplicationContext> supplier) {
		return (webApplicationType) -> supplier.get();
	}

}