wordcount - модифицированный пример - изменение кода - hadoop

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* 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 hadoop.mytest;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Partitioner;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import java.net.InetAddress; //

public class WordCount {

public static class TokenizerMapper
extends Mapper<Object, Text, Text, IntWritable>{

private static final Integer inNum = new Integer(1);
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();

public void map(Object key, Text value, Context context
) throws IOException, InterruptedException {
StringTokenizer itr = new StringTokenizer(value.toString());
while (itr.hasMoreTokens()) {
word.set(itr.nextToken());

String computername=InetAddress.getLocalHost().getHostName(); // get PC name
context.write(new Text( " PC = " + computername), new IntWritable(0));

context.write(word, one);

//if (inNum == 3) {
// context.write(word, one);
// }
}
}
}

public static class IntSumReducer
extends Reducer<Text,IntWritable,Text,IntWritable> {
int max_sum = 0;
Text max_occured_key = new Text();

@Override
protected void cleanup(Context context) throws InterruptedException {
try{
context.write(new Text("----maximum===== "), new IntWritable(0));

String computername=InetAddress.getLocalHost().getHostName(); // get PC name
context.write(max_occured_key, new IntWritable(max_sum));
context.write(new Text( " PC = " + computername), new IntWritable(0));
context.write(new Text("-------------- "), new IntWritable(0));
}
catch(IOException e){
e.printStackTrace();
}
}
@Override
protected void setup(Context context) throws IOException,
InterruptedException{
try{
context.write(new Text("reduser start "), new IntWritable(0));
}
catch(IOException e){
e.printStackTrace();
}
}

private IntWritable result = new IntWritable();

public void reduce(Text key, Iterable<IntWritable> values,
Context context
) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
if(sum > max_sum)
{
max_sum = sum;
//max_occured_key = key;
max_occured_key.set(key);
}

//context.write(max_occured_key, new IntWritable(max_sum));
result.set(sum);
// if (sum > 1) {
String computername=InetAddress.getLocalHost().getHostName(); // get PC name
context.write(new Text( " PC = " + computername), new IntWritable(0));
context.write(key, result);
//}
}
}

public static class IntSumCombiner
extends Reducer<Text,IntWritable,Text,IntWritable> {
int max_sum = 0;
Text max_occured_key = new Text();

@Override
protected void cleanup(Context context) throws InterruptedException {
try{
context.write(new Text("----maximum of combiner===== "), new IntWritable(0));
context.write(max_occured_key, new IntWritable(max_sum));
context.write(new Text("-------------- "), new IntWritable(0));
}
catch(IOException e){
e.printStackTrace();
}
}
@Override
protected void setup(Context context) throws IOException,
InterruptedException{
try{
context.write(new Text("----combiner start-------"), new IntWritable(0));
}
catch(IOException e){
e.printStackTrace();
}
}

private IntWritable result = new IntWritable();

public void reduce(Text key, Iterable<IntWritable> values,
Context context
) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
if(sum > max_sum)
{
max_sum = sum;
//max_occured_key = key;
max_occured_key.set(key);
}
//context.write(max_occured_key, new IntWritable(max_sum));
result.set(sum);
// if (sum > 1) {
context.write(key, result);
//}
}
}

/*
public class ExpPartitioner extends Partitioner<Text, IntWritable>
{
@Override
public int getPartition (Text key,IntWritable value, int numPartions)
{
return 1;

}
} */

public static void main(String[] args) throws Exception {

Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
if (otherArgs.length != 2) {
System.err.println("Usage: wordcount <in> <out>");
System.exit(2);
}

Job job = new Job(conf, "word count");
job.setJarByClass(WordCount.class);
job.setMapperClass(TokenizerMapper.class);
job.setCombinerClass(IntSumCombiner.class);
job.setReducerClass(IntSumReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
job.setNumReduceTasks(2);

//System.out.println(otherArgs[0]);
//System.out.println(otherArgs[1]);

//String computername=InetAddress.getLocalHost().getHostName();
//System.out.println(computername);

System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}