标准wordcount

package wordcount;

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.lib.input.FileInputFormat;

import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class WordCount{

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

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{

String line=value.toString();

StringTokenizer tokenizer = new StringTokenizer(line);

while(tokenizer.hasMoreTokens()){

word.set(tokenizer.nextToken());

context.write(word, one);

}

}

}

public static class WordReduce extends Reducer<Text,IntWritable,Text,IntWritable>{

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();

}

result.set(sum);

context.write(key,result);

}

}

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

{

Configuration conf =new Configuration();

Job job =new Job(conf,"WordCount");

job.setJarByClass(WordMap.class);

job.setMapperClass(WordMap.class);

job.setReducerClass(WordReduce.class);

job.setOutputKeyClass(Text.class);

job.setOutputValueClass(IntWritable.class);

FileInputFormat.addInputPath(job,new Path(args[0]));

FileOutputFormat.setOutputPath(job,new Path(args[1]));//setOutputPath(job,new Path(args[1]));

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

}

}

标准wordcount