哪位前輩或者老師幫忙看下是怎么回事唄。。。

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.LongWritable;

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.input.TextInputFormat;

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

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

public class WordCount {

public static class WordCountMap extends

Mapper<LongWritable, Text, Text, IntWritable> {

private final IntWritable one = new IntWritable(1);

private Text word = new Text();

public void map(LongWritable key, Text value, Context context)

throws IOException, InterruptedException {

String line = value.toString();

StringTokenizer token = new StringTokenizer(line);

while (token.hasMoreTokens()) {

word.set(token.nextToken());

context.write(word, one);

}

}

}

public static class WordCountReduce extends

Reducer<Text, IntWritable, Text, IntWritable> {

public void reduce(Text key, Iterable<IntWritable> values,

Context context) throws IOException, InterruptedException {

int sum = 0;

for (IntWritable val : values) {

sum += val.get();

}

context.write(key, new IntWritable(sum));

}

}

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

Configuration conf = new Configuration();

Job job = new Job(conf);

job.setJarByClass(WordCount.class);

job.setJobName("wordcount");

job.setOutputKeyClass(Text.class);

job.setOutputValueClass(IntWritable.class);

job.setMapperClass(WordCountMap.class);

job.setReducerClass(WordCountReduce.class);

job.setInputFormatClass(TextInputFormat.class);

job.setOutputFormatClass(TextOutputFormat.class);

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

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

job.waitForCompletion(true);

}

}

這是之前給的源代碼