001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package org.apache.hadoop.mapred.lib;
020    
021    import org.apache.hadoop.classification.InterfaceAudience;
022    import org.apache.hadoop.classification.InterfaceStability;
023    import org.apache.hadoop.fs.FileSystem;
024    import org.apache.hadoop.mapred.JobConf;
025    import org.apache.hadoop.mapred.OutputFormat;
026    import org.apache.hadoop.mapred.RecordWriter;
027    import org.apache.hadoop.mapred.Reporter;
028    import org.apache.hadoop.util.Progressable;
029    
030    /**
031     * Consume all outputs and put them in /dev/null. 
032     */
033    @InterfaceAudience.Public
034    @InterfaceStability.Stable
035    public class NullOutputFormat<K, V> implements OutputFormat<K, V> {
036      
037      public RecordWriter<K, V> getRecordWriter(FileSystem ignored, JobConf job, 
038                                          String name, Progressable progress) {
039        return new RecordWriter<K, V>(){
040            public void write(K key, V value) { }
041            public void close(Reporter reporter) { }
042          };
043      }
044      
045      public void checkOutputSpecs(FileSystem ignored, JobConf job) { }
046    }