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.mapreduce;
020
021 import java.io.IOException;
022
023 import org.apache.hadoop.classification.InterfaceAudience;
024 import org.apache.hadoop.classification.InterfaceStability;
025 import org.apache.hadoop.fs.FileSystem;
026
027 /**
028 * <code>RecordWriter</code> writes the output <key, value> pairs
029 * to an output file.
030
031 * <p><code>RecordWriter</code> implementations write the job outputs to the
032 * {@link FileSystem}.
033 *
034 * @see OutputFormat
035 */
036 @InterfaceAudience.Public
037 @InterfaceStability.Stable
038 public abstract class RecordWriter<K, V> {
039 /**
040 * Writes a key/value pair.
041 *
042 * @param key the key to write.
043 * @param value the value to write.
044 * @throws IOException
045 */
046 public abstract void write(K key, V value
047 ) throws IOException, InterruptedException;
048
049 /**
050 * Close this <code>RecordWriter</code> to future operations.
051 *
052 * @param context the context of the task
053 * @throws IOException
054 */
055 public abstract void close(TaskAttemptContext context
056 ) throws IOException, InterruptedException;
057 }