| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.rya.api.utils; |
| |
| import org.eclipse.rdf4j.model.IRI; |
| import org.eclipse.rdf4j.model.Literal; |
| import org.eclipse.rdf4j.model.util.Literals; |
| import org.eclipse.rdf4j.model.vocabulary.RDF; |
| |
| /** |
| * Utility methods and constants for {@link Literal} languages. |
| */ |
| public final class LiteralLanguageUtils { |
| /** |
| * Special identifier used if there is language content, but the specific |
| * language cannot be determined. Should be avoided if possible. |
| * See <a href=https://www.loc.gov/standards/iso639-2/faq.html#25>here</a> |
| * for more info. |
| */ |
| public static final String UNDETERMINED_LANGUAGE = "und"; |
| |
| /** |
| * Delimiter between the data and the language tag. |
| */ |
| public static final String LANGUAGE_DELIMITER = "@"; |
| |
| /** |
| * Private constructor to prevent instantiation. |
| */ |
| private LiteralLanguageUtils() { |
| } |
| |
| /** |
| * Validates the language based on the data type. |
| * <p> |
| * This will do one of the following: |
| * <ul> |
| * <li>Return the original {@code language} if the {@code dataType} is |
| * {@link RDF#LANGSTRING} and it's of a VALID format.</li> |
| * <li>Returns {@link UNDETERMINED_LANGUAGE} if the {@code dataType} is |
| * {@link RDF#LANGSTRING} and it's of an INVALID format.</li> |
| * <li>Return {@code null} if the dataType is NOT {@link RDF#LANGSTRING}.</li> |
| * </ul> |
| * @param language the language to validate. |
| * @param dataType the {@link IRI} data type to validate against. |
| * @return the validated language. |
| */ |
| public static String validateLanguage(final String language, final IRI dataType) { |
| String result = null; |
| if (RDF.LANGSTRING.equals(dataType)) { |
| if (language != null && Literals.isValidLanguageTag(language)) { |
| result = language; |
| } else { |
| result = UNDETERMINED_LANGUAGE; |
| } |
| } |
| return result; |
| } |
| } |