FilteringSpringBootCondition Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/FilteringSpringBootCondition.java lines 42–160

abstract class FilteringSpringBootCondition extends SpringBootCondition
		implements AutoConfigurationImportFilter, BeanFactoryAware, BeanClassLoaderAware {

	@SuppressWarnings("NullAway.Init")
	private BeanFactory beanFactory;

	@SuppressWarnings("NullAway.Init")
	private ClassLoader beanClassLoader;

	@Override
	public boolean[] match(@Nullable String[] autoConfigurationClasses,
			AutoConfigurationMetadata autoConfigurationMetadata) {
		ConditionEvaluationReport report = ConditionEvaluationReport.find(this.beanFactory);
		@Nullable ConditionOutcome[] outcomes = getOutcomes(autoConfigurationClasses, autoConfigurationMetadata);
		boolean[] match = new boolean[outcomes.length];
		for (int i = 0; i < outcomes.length; i++) {
			ConditionOutcome outcome = outcomes[i];
			match[i] = (outcome == null || outcome.isMatch());
			if (!match[i] && outcome != null) {
				String autoConfigurationClass = autoConfigurationClasses[i];
				Assert.state(autoConfigurationClass != null, "'autoConfigurationClass' must not be null");
				logOutcome(autoConfigurationClass, outcome);
				if (report != null) {
					report.recordConditionEvaluation(autoConfigurationClass, this, outcome);
				}
			}
		}
		return match;
	}

	protected abstract @Nullable ConditionOutcome[] getOutcomes(@Nullable String[] autoConfigurationClasses,
			AutoConfigurationMetadata autoConfigurationMetadata);

	@Override
	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
		this.beanFactory = beanFactory;
	}

	protected final BeanFactory getBeanFactory() {
		return this.beanFactory;
	}

	protected final ClassLoader getBeanClassLoader() {
		return this.beanClassLoader;
	}

	@Override
	public void setBeanClassLoader(ClassLoader classLoader) {
		this.beanClassLoader = classLoader;
	}

	protected final List<String> filter(@Nullable Collection<String> classNames, ClassNameFilter classNameFilter,
			@Nullable ClassLoader classLoader) {
		if (CollectionUtils.isEmpty(classNames)) {
			return Collections.emptyList();
		}
		List<String> matches = new ArrayList<>(classNames.size());
		for (String candidate : classNames) {
			if (classNameFilter.matches(candidate, classLoader)) {
				matches.add(candidate);
			}
		}
		return matches;
	}

	/**
	 * Slightly faster variant of {@link ClassUtils#forName(String, ClassLoader)} that
	 * doesn't deal with primitives, arrays or inner types.
	 * @param className the class name to resolve
	 * @param classLoader the class loader to use
	 * @return a resolved class
	 * @throws ClassNotFoundException if the class cannot be found
	 */
	protected static Class<?> resolve(String className, @Nullable ClassLoader classLoader)
			throws ClassNotFoundException {
		if (classLoader != null) {
			return Class.forName(className, false, classLoader);
		}
		return Class.forName(className);
	}

	protected enum ClassNameFilter {

		PRESENT {

			@Override
			public boolean matches(String className, @Nullable ClassLoader classLoader) {
				return isPresent(className, classLoader);
			}

		},

		MISSING {

			@Override
			public boolean matches(String className, @Nullable ClassLoader classLoader) {
				return !isPresent(className, classLoader);
			}

		};

		abstract boolean matches(String className, @Nullable ClassLoader classLoader);

		private static boolean isPresent(String className, @Nullable ClassLoader classLoader) {
			if (classLoader == null) {
				classLoader = ClassUtils.getDefaultClassLoader();
			}
			try {
				resolve(className, classLoader);
				return true;
			}
			catch (Throwable ex) {
				return false;
			}
		}

	}

}