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.lib; 020 021import org.apache.hadoop.classification.InterfaceAudience; 022import org.apache.hadoop.classification.InterfaceStability; 023import org.apache.hadoop.mapred.JobConf; 024import org.apache.hadoop.mapred.Partitioner; 025 026 /** 027 * Defines a way to partition keys based on certain key fields (also see 028 * {@link KeyFieldBasedComparator}. 029 * The key specification supported is of the form -k pos1[,pos2], where, 030 * pos is of the form f[.c][opts], where f is the number 031 * of the key field to use, and c is the number of the first character from 032 * the beginning of the field. Fields and character posns are numbered 033 * starting with 1; a character position of zero in pos2 indicates the 034 * field's last character. If '.c' is omitted from pos1, it defaults to 1 035 * (the beginning of the field); if omitted from pos2, it defaults to 0 036 * (the end of the field). 037 */ 038@InterfaceAudience.Public 039@InterfaceStability.Stable 040public class KeyFieldBasedPartitioner<K2, V2> extends 041 org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedPartitioner<K2, V2> 042 implements Partitioner<K2, V2> { 043 044 public void configure(JobConf job) { 045 super.setConf(job); 046 } 047}