/*
* 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;
import org.apache.jena.hadoop.rdf.types.NodeWritable;
import org.apache.jena.hadoop.rdf.types.QuadWritable;
import org.apache.jena.sparql.core.Quad ;
/**
* A mapper for counting node usages within quads designed primarily for use in
* conjunction with {@link NodeCountReducer}
*
*
*
* @param <TKey>
* Key type
*/
public class QuadNodeCountMapper<TKey> extends AbstractNodeTupleNodeCountMapper<TKey, Quad, QuadWritable> {
@Override
protected NodeWritable[] getNodes(QuadWritable tuple) {
Quad q = tuple.get();
return new NodeWritable[] { new NodeWritable(q.getGraph()), new NodeWritable(q.getSubject()),
new NodeWritable(q.getPredicate()), new NodeWritable(q.getObject()) };
}
}