10月30日课堂测试

package mapreduce;

import java.io.IOException;

import java.util.StringTokenizer;

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 WordCount1{

public static void main(String[] args) throws IOException,ClassNotFoundException,InterruptedException {

Job job = Job.getInstance();

job.setJobName("WordCount1");

job.setJarByClass(WordCount1.class);

job.setMapperClass(doMapper.class);

job.setReducerClass(doReducer.class);

job.setOutputKeyClass(Text.class);

job.setOutputValueClass(IntWritable.class);

Path in = new Path("hdfs://localhost:9000/mymapreduce1/in/buyer_favorite1");

Path out = new Path("hdfs://localhost:9000/mymapreduce1/out");

FileInputFormat.addInputPath(job,in);

FileOutputFormat.setOutputPath(job,out);

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

}

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

public static final IntWritable one = new IntWritable(1);

public static Text word = new Text();

@Override

protected void map(Object key, Text value, Context context)

throws IOException,InterruptedException {

StringTokenizer tokenizer = new StringTokenizer(value.toString(),"  ");

word.set(tokenizer.nextToken());

context.write(word,one);

}

}

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

private IntWritable result = new IntWritable();

@Override

protected void reduce(Text key,Iterable<IntWritable> values,Context context)

throws IOException,InterruptedException{

int sum = 0;

for (IntWritable value : values){

sum += value.get();

}

result.set(sum);

context.write(key,result);

}

}

}

　　

 

buyer_favorite1文件内容：

 

 

 

运行结果：