Java tutorial
/* * Copyright 2015 herd contributors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.finra.herd.service; import java.util.HashSet; import java.util.Set; import org.apache.commons.lang3.StringUtils; import org.springframework.util.Assert; /** * Service interface to support facet fields validation. */ public interface FacetFieldValidationService { /** * Returns valid facet fields. * * @return the set of valid facet fields */ public Set<String> getValidFacetFields(); /** * Validates a set of facet fields. This method also trims and lowers the fields. * * @param facetFields the facet fields to be validated * @return the set of facet fields */ default Set<String> validateFacetFields(Set<String> facetFields) { // Create a local copy of the fields set so that we can stream it to modify the fields set Set<String> localCopy = new HashSet<>(facetFields); // Clear the fields set facetFields.clear(); // Add to the fields set field the strings both trimmed and lower cased and filter out empty and null strings localCopy.stream().filter(StringUtils::isNotBlank).map(String::trim).map(String::toLowerCase) .forEachOrdered(facetFields::add); // Validate the field names facetFields.forEach(field -> Assert.isTrue(getValidFacetFields().contains(field), String.format("Facet field \"%s\" is not supported.", field))); return facetFields; } }