/** * Vocabulary * Copyright 2011 by Michael Peter Christen, mc@yacy.net, Frankfurt am Main, Germany * First released 16.12.2011 at http://yacy.net * * $LastChangedDate: 2011-04-14 00:04:23 +0200 (Do, 14 Apr 2011) $ * $LastChangedRevision: 7653 $ * $LastChangedBy: orbiter $ * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program in the file lgpl21.txt * If not, see <http://www.gnu.org/licenses/>. */ package net.yacy.cora.lod; import java.util.Set; /* * A Vocabulary is an interface to an 'extensible enum pattern'. * We want to have an kind of extensible enum for vocabularies. * Since enum classes cannot be extended we use a hack as explained in * http://blogs.oracle.com/darcy/entry/enums_and_mixins . * For an example for 'extensible enum pattern' see * http://stackoverflow.com/questions/1414755/java-extend-enum */ public interface Vocabulary { /** * get the RDF identifier as an URL stub * @return */ public String getNamespace(); /** * get the prefix for the predicates of this vocabulary * @return */ public String getNamespacePrefix(); /** * get the predicate name which already contains the prefix url stub * @return */ public String getPredicate(); /** * The URI Reference as defined in http://www.w3.org/TR/rdf-concepts/ 2.2.3 * This is a combination of the namespace prefic and the constant name, * concatenated with ':'. * @return */ public String getURIref(); /** * get a set of literals that are allowed for the predicate as values * @return */ public Set<Literal> getLiterals(); /** * the name method is identical to the java.lang.Enum method. * If an Enum class for vocabularies * implements this interface, the name() method is automatically implemented * * @return Returns the name of the enum constant as declared in the enum declaration. */ public String name(); }