| /** |
| * 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.hadoop.mapred.lib; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.mapred.JobConf; |
| import org.apache.hadoop.mapred.JobConfigurable; |
| import org.apache.hadoop.mapreduce.JobContext; |
| |
| /** |
| * This comparator implementation provides a subset of the features provided |
| * by the Unix/GNU Sort. In particular, the supported features are: |
| * -n, (Sort numerically) |
| * -r, (Reverse the result of comparison) |
| * -k pos1[,pos2], where pos is of the form f[.c][opts], where f is the number |
| * of the field to use, and c is the number of the first character from the |
| * beginning of the field. Fields and character posns are numbered starting |
| * with 1; a character position of zero in pos2 indicates the field's last |
| * character. If '.c' is omitted from pos1, it defaults to 1 (the beginning |
| * of the field); if omitted from pos2, it defaults to 0 (the end of the |
| * field). opts are ordering options (any of 'nr' as described above). |
| * We assume that the fields in the key are separated by |
| * {@link JobContext#MAP_OUTPUT_KEY_FIELD_SEPERATOR} |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class KeyFieldBasedComparator<K, V> extends |
| org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedComparator<K, V> |
| implements JobConfigurable { |
| |
| public void configure(JobConf job) { |
| super.setConf(job); |
| } |
| } |
