MemberConditions Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/AbstractNestedCondition.java lines 104–176

	private static class MemberConditions {

		private final ConditionContext context;

		private final MetadataReaderFactory readerFactory;

		private final Map<AnnotationMetadata, List<Condition>> memberConditions;

		MemberConditions(ConditionContext context, ConfigurationPhase phase, String className) {
			this.context = context;
			this.readerFactory = new SimpleMetadataReaderFactory(context.getResourceLoader());
			String[] members = getMetadata(className).getMemberClassNames();
			this.memberConditions = getMemberConditions(members, phase, className);
		}

		private Map<AnnotationMetadata, List<Condition>> getMemberConditions(String[] members, ConfigurationPhase phase,
				String className) {
			MultiValueMap<AnnotationMetadata, Condition> memberConditions = new LinkedMultiValueMap<>();
			for (String member : members) {
				AnnotationMetadata metadata = getMetadata(member);
				for (String[] conditionClasses : getConditionClasses(metadata)) {
					for (String conditionClass : conditionClasses) {
						Condition condition = getCondition(conditionClass);
						validateMemberCondition(condition, phase, className);
						memberConditions.add(metadata, condition);
					}
				}
			}
			return Collections.unmodifiableMap(memberConditions);
		}

		private void validateMemberCondition(Condition condition, ConfigurationPhase nestedPhase,
				String nestedClassName) {
			if (nestedPhase == ConfigurationPhase.PARSE_CONFIGURATION
					&& condition instanceof ConfigurationCondition configurationCondition) {
				ConfigurationPhase memberPhase = configurationCondition.getConfigurationPhase();
				if (memberPhase == ConfigurationPhase.REGISTER_BEAN) {
					throw new IllegalStateException("Nested condition " + nestedClassName + " uses a configuration "
							+ "phase that is inappropriate for " + condition.getClass());
				}
			}
		}

		private AnnotationMetadata getMetadata(String className) {
			try {
				return this.readerFactory.getMetadataReader(className).getAnnotationMetadata();
			}
			catch (IOException ex) {
				throw new IllegalStateException(ex);
			}
		}

		@SuppressWarnings("unchecked")
		private List<String[]> getConditionClasses(AnnotatedTypeMetadata metadata) {
			MultiValueMap<String, @Nullable Object> attributes = metadata
				.getAllAnnotationAttributes(Conditional.class.getName(), true);
			Object values = (attributes != null) ? attributes.get("value") : null;
			return (List<String[]>) ((values != null) ? values : Collections.emptyList());
		}

		private Condition getCondition(String conditionClassName) {
			Class<?> conditionClass = ClassUtils.resolveClassName(conditionClassName, this.context.getClassLoader());
			return (Condition) BeanUtils.instantiateClass(conditionClass);
		}

		List<ConditionOutcome> getMatchOutcomes() {
			List<ConditionOutcome> outcomes = new ArrayList<>();
			this.memberConditions.forEach((metadata, conditions) -> outcomes
				.add(new MemberOutcomes(this.context, metadata, conditions).getUltimateOutcome()));
			return Collections.unmodifiableList(outcomes);
		}

	}