1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.commons.rdf.api; 19 20 /** 21 * A generalised "triple-like" interface, extended by {@link Triple} and 22 * {@link Quad}. 23 * <p> 24 * A TripleLike statement has at least a {@link #getSubject()}, 25 * {@link #getPredicate()} and {@link #getObject()}, but unlike a {@link Triple} 26 * does not have a formalised {@link Triple#equals(Object)} or 27 * {@link Triple#hashCode()} semantics and is not required to be 28 * <em>immutable</em> or <em>thread-safe</em>. This interfaced can also be used 29 * for <em>generalised triples</em> (e.g. a {@link BlankNode} as predicate). 30 * <p> 31 * Implementations should specialise which specific {@link RDFTerm} types they 32 * return by overriding {@link #getSubject()}, {@link #getPredicate()} and 33 * {@link #getObject()}. 34 * 35 * 36 * @since 0.3.0-incubating 37 * @see Triple 38 * @see Quad 39 * @see QuadLike 40 */ 41 public interface TripleLike { 42 43 /** 44 * The subject of this statement. 45 * 46 * @return The subject, typically an {@link IRI} or {@link BlankNode}. 47 */ 48 RDFTerm getSubject(); 49 50 /** 51 * The predicate of this statement. 52 * 53 * @return The predicate, typically an {@link IRI}. 54 */ 55 RDFTerm getPredicate(); 56 57 /** 58 * The object of this statement. 59 * 60 * @return The object, typically an {@link IRI}, {@link BlankNode} or 61 * {@link Literal}. 62 */ 63 RDFTerm getObject(); 64 }