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 019package org.apache.hadoop.mapred; 020 021import java.io.IOException; 022 023import org.apache.hadoop.classification.InterfaceAudience; 024import org.apache.hadoop.classification.InterfaceStability; 025import 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 038public interface 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 void write(K key, V value) throws IOException; 047 048 /** 049 * Close this <code>RecordWriter</code> to future operations. 050 * 051 * @param reporter facility to report progress. 052 * @throws IOException 053 */ 054 void close(Reporter reporter) throws IOException; 055}