evaluateConditionalOnSingleCandidate() — spring-boot Function Reference

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnBeanCondition.java lines 168–200

	private ConditionOutcome evaluateConditionalOnSingleCandidate(Spec<ConditionalOnSingleCandidate> spec,
			ConditionMessage matchMessage) {
		MatchResult matchResult = getMatchingBeans(spec);
		if (!matchResult.isAllMatched()) {
			return ConditionOutcome.noMatch(spec.message().didNotFind("any beans").atAll());
		}
		Set<String> allBeans = matchResult.getNamesOfAllMatches();
		if (allBeans.size() == 1) {
			return ConditionOutcome
				.match(spec.message(matchMessage).found("a single bean").items(Style.QUOTE, allBeans));
		}
		ConfigurableListableBeanFactory beanFactory = spec.context.getBeanFactory();
		Assert.state(beanFactory != null, "'beanFactory' must not be null");
		Map<String, @Nullable BeanDefinition> beanDefinitions = getBeanDefinitions(beanFactory, allBeans,
				spec.getStrategy() == SearchStrategy.ALL);
		List<String> primaryBeans = getPrimaryBeans(beanDefinitions);
		if (primaryBeans.size() == 1) {
			return ConditionOutcome.match(spec.message(matchMessage)
				.found("a single primary bean '" + primaryBeans.get(0) + "' from beans")
				.items(Style.QUOTE, allBeans));
		}
		if (primaryBeans.size() > 1) {
			return ConditionOutcome
				.noMatch(spec.message().found("multiple primary beans").items(Style.QUOTE, primaryBeans));
		}
		List<String> nonFallbackBeans = getNonFallbackBeans(beanDefinitions);
		if (nonFallbackBeans.size() == 1) {
			return ConditionOutcome.match(spec.message(matchMessage)
				.found("a single non-fallback bean '" + nonFallbackBeans.get(0) + "' from beans")
				.items(Style.QUOTE, allBeans));
		}
		return ConditionOutcome.noMatch(spec.message().found("multiple beans").items(Style.QUOTE, allBeans));
	}