/*
* 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.io.output;
import java.io.Writer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.jena.hadoop.rdf.types.AbstractNodeTupleWritable;
import org.apache.jena.riot.system.StreamRDF;
/**
* Abstract output format for formats that use the RIOT {@link StreamRDF} API to
* stream the writes
*
* @param <TKey>
* Key type
* @param <TTuple>
* Tuple type
* @param <TValue>
* Writable tuple type i.e. the value type
*/
public abstract class AbstractStreamRdfNodeTupleOutputFormat<TKey, TTuple, TValue extends AbstractNodeTupleWritable<TTuple>>
extends AbstractNodeTupleOutputFormat<TKey, TTuple, TValue> {
@Override
protected RecordWriter<TKey, TValue> getRecordWriter(Writer writer, Configuration config, Path outputPath) {
return getRecordWriter(getStream(writer, config), writer, config);
}
/**
* Gets a writer which provides a bridge between the {@link RecordWriter}
* and {@link StreamRDF} APIs
*
* @param stream
* RDF Stream
* @param writer
* Writer
* @param config
* Configuration
* @return Record Writer
*/
protected abstract RecordWriter<TKey, TValue> getRecordWriter(StreamRDF stream, Writer writer, Configuration config);
/**
* Gets a {@link StreamRDF} to which the tuples to be output should be
* passed
*
* @param writer
* Writer
* @param config
* Configuration
* @return RDF Stream
*/
protected abstract StreamRDF getStream(Writer writer, Configuration config);
}