/**
* 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.hive.contrib.mr.example;
import java.util.Iterator;
import org.apache.hadoop.hive.contrib.mr.GenericMR;
import org.apache.hadoop.hive.contrib.mr.Output;
import org.apache.hadoop.hive.contrib.mr.Reducer;
/**
* Example Reducer (WordCount).
*/
public final class WordCountReduce {
private WordCountReduce() {
// prevent instantiation
}
public static void main(final String[] args) throws Exception {
new GenericMR().reduce(System.in, System.out, new Reducer() {
public void reduce(String key, Iterator<String[]> records, Output output)
throws Exception {
int count = 0;
while (records.hasNext()) {
// note we use col[1] -- the key is provided again as col[0]
count += Integer.parseInt(records.next()[1]);
}
output.collect(new String[] {key, String.valueOf(count)});
}
});
}
}