@Override
public String[] selectImports(AnnotationMetadata annotationMetadata) {if (!isEnabled(annotationMetadata)) {return NO_IMPORTS;}AutoConfigurationMetadata autoConfigurationMetadata = AutoConfigurationMetadataLoader.loadMetadata(this.beanClassLoader);AnnotationAttributes attributes = getAttributes(annotationMetadata);List<String> configurations = getCandidateConfigurations(annotationMetadata,attributes);configurations = removeDuplicates(configurations);Set<String> exclusions = getExclusions(annotationMetadata, attributes);checkExcludedClasses(configurations, exclusions);configurations.removeAll(exclusions);configurations = filter(configurations, autoConfigurationMetadata);fireAutoConfigurationImportEvents(configurations, exclusions);return StringUtils.toStringArray(configurations);
}

private List<String> filter(List<String> configurations,AutoConfigurationMetadata autoConfigurationMetadata) {long startTime = System.nanoTime();String[] candidates = StringUtils.toStringArray(configurations);boolean[] skip = new boolean[candidates.length];boolean skipped = false;for (AutoConfigurationImportFilter filter : getAutoConfigurationImportFilters()) {invokeAwareMethods(filter);boolean[] match = filter.match(candidates, autoConfigurationMetadata);for (int i = 0; i < match.length; i++) {if (!match[i]) {skip[i] = true;skipped = true;}}}if (!skipped) {return configurations;}List<String> result = new ArrayList<>(candidates.length);for (int i = 0; i < candidates.length; i++) {if (!skip[i]) {result.add(candidates[i]);}}if (logger.isTraceEnabled()) {int numberFiltered = configurations.size() - result.size();logger.trace("Filtered " + numberFiltered + " auto configuration class in "+ TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime)+ " ms");}return new ArrayList<>(result);
}

private ConditionOutcome[] getOutcomes(String[] autoConfigurationClasses,int start, int end, AutoConfigurationMetadata autoConfigurationMetadata) {ConditionOutcome[] outcomes = new ConditionOutcome[end - start];for (int i = start; i < end; i++) {String autoConfigurationClass = autoConfigurationClasses[i];Set<String> candidates = autoConfigurationMetadata.getSet(autoConfigurationClass, "ConditionalOnClass");if (candidates != null) {outcomes[i - start] = getOutcome(candidates);}}return outcomes;
}private ConditionOutcome getOutcome(Set<String> candidates) {try {List<String> missing = getMatches(candidates, MatchType.MISSING,this.beanClassLoader);if (!missing.isEmpty()) {return ConditionOutcome.noMatch(ConditionMessage.forCondition(ConditionalOnClass.class).didNotFind("required class", "required classes").items(Style.QUOTE, missing));}}catch (Exception ex) {// We'll get another chance later}return null;
}