Java tutorial
/** * 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.jena.commonsrdf.impl; import java.io.StringWriter; import java.util.Iterator; import java.util.stream.Stream; import org.apache.commons.rdf.api.*; import org.apache.jena.atlas.iterator.Iter; import org.apache.jena.commonsrdf.JenaCommonsRDF; import org.apache.jena.graph.Node; import org.apache.jena.riot.Lang; import org.apache.jena.riot.RDFDataMgr; public class JCR_Graph implements Graph, JenaGraph { private org.apache.jena.graph.Graph graph; /*package*/ JCR_Graph(org.apache.jena.graph.Graph graph) { this.graph = graph; } @Override public org.apache.jena.graph.Graph getGraph() { return graph; } @Override public void add(Triple triple) { graph.add(JenaCommonsRDF.toJena(triple)); } @Override public void add(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) { graph.add(org.apache.jena.graph.Triple.create(JenaCommonsRDF.toJena(subject), JenaCommonsRDF.toJena(predicate), JenaCommonsRDF.toJena(object))); } @Override public boolean contains(Triple triple) { return graph.contains(JenaCommonsRDF.toJena(triple)); } @Override public boolean contains(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) { return graph.contains(JenaCommonsRDF.toJena(subject), JenaCommonsRDF.toJena(predicate), JenaCommonsRDF.toJena(object)); } @Override public void remove(Triple triple) { graph.delete(JenaCommonsRDF.toJena(triple)); } @Override public void remove(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) { graph.delete(org.apache.jena.graph.Triple.create(JenaCommonsRDF.toJena(subject), JenaCommonsRDF.toJena(predicate), JenaCommonsRDF.toJena(object))); } @Override public void clear() { graph.clear(); } @Override public long size() { return graph.size(); } @Override public Stream<? extends Triple> getTriples() { return getTriples(null, null, null); } @Override public Stream<? extends Triple> getTriples(BlankNodeOrIRI subject, IRI predicate, RDFTerm object) { Iterator<org.apache.jena.graph.Triple> iter = graph.find(toJenaAny(subject), toJenaAny(predicate), toJenaAny(object)); Iterator<Triple> iter2 = Iter.map(iter, t -> JenaCommonsRDF.fromJena(t)); return Iter.asStream(iter2); } private Node toJenaAny(RDFTerm term) { if (term == null) return Node.ANY; return JenaCommonsRDF.toJena(term); } @Override public void close() { graph.close(); } @Override public String toString() { StringWriter sw = new StringWriter(); RDFDataMgr.write(sw, graph, Lang.NT); return sw.toString(); } }