| /* |
| * 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.hadoop.rdf.mapreduce.count.datatypes; |
| |
| import org.apache.jena.graph.Node ; |
| import org.apache.jena.graph.NodeFactory ; |
| import org.apache.jena.hadoop.rdf.mapreduce.count.NodeCountReducer; |
| import org.apache.jena.hadoop.rdf.mapreduce.count.TripleNodeCountMapper; |
| import org.apache.jena.hadoop.rdf.types.NodeWritable; |
| import org.apache.jena.hadoop.rdf.types.TripleWritable; |
| |
| /** |
| * A mapper for counting data type usages within triples designed primarily for |
| * use in conjunction with {@link NodeCountReducer} |
| * <p> |
| * This mapper extracts the data types for typed literal objects and converts |
| * them into nodes so they can be counted |
| * </p> |
| * |
| * |
| * |
| * @param <TKey> |
| * Key type |
| */ |
| public class TripleDataTypeCountMapper<TKey> extends TripleNodeCountMapper<TKey> { |
| |
| private static final NodeWritable[] EMPTY = new NodeWritable[0]; |
| |
| @Override |
| protected NodeWritable[] getNodes(TripleWritable tuple) { |
| Node object = tuple.get().getObject(); |
| if (!object.isLiteral()) |
| return EMPTY; |
| String dtUri = object.getLiteralDatatypeURI(); |
| if (dtUri == null) |
| return EMPTY; |
| return new NodeWritable[] { new NodeWritable(NodeFactory.createURI(dtUri)) }; |
| } |
| } |