@Audit(action = AuditableActions.SAML2_METADATA_RESOLUTION,
        actionResolverName = AuditActionResolvers.SAML2_METADATA_RESOLUTION_ACTION_RESOLVER,
        resourceResolverName = AuditResourceResolvers.SAML2_METADATA_RESOLUTION_RESOURCE_RESOLVER)
    @Override
    public Collection<? extends MetadataResolver> resolve(final SamlRegisteredService service, final CriteriaSet criteriaSet) {
        val listOfResolvers = new ArrayList<MetadataResolver>();
        try {
            val metadataLocations = org.springframework.util.StringUtils.commaDelimitedListToSet(
                SpringExpressionLanguageValueResolver.getInstance().resolve(service.getMetadataLocation())
            );
            for (val metadataLocation : metadataLocations) {
                if (isMetadataFileSystemResource(metadataLocation)) {
                    LOGGER.info("Loading SAML metadata from [{}]", metadataLocation);
                    val metadataResource = ResourceUtils.getResourceFrom(metadataLocation);
                    val metadataFile = metadataResource.getFile();
                    val metadataResolver = getMetadataResolver(metadataResource, metadataFile);
                    configureAndInitializeSingleMetadataResolver(metadataResolver, service);
                    listOfResolvers.add(metadataResolver);
                }
            }
        } catch (final Exception e) {
            LoggingUtils.error(LOGGER, e);
        }
        return listOfResolvers;
    }
This is {@link FileSystemResourceMetadataResolver}.

@author Misagh Moayyed
@since 5.2.0
support/cas-server-support-saml-idp-metadata/src/main/java/org/apereo/cas/support/saml/services/idp/metadata/cache/resolver/FileSystemResourceMetadataResolver.java