hadoop 多個maper處理

package com.smilezl.learn.CalWord;

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.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.MultipleInputs;

import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;

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

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

import org.apache.hadoop.util.GenericOptionsParser;

public class MultipleMapper {

public static class DeptMapper extends Mapper<Object, Text, Text, Text> {

@Override

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

throws IOException, InterruptedException {

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

String tmp = "";

while (tokenizer.hasMoreTokens()) {

tmp += tokenizer.nextToken().toString();

}

context.write(new Text("dept"), new Text(tmp));

}

}

public static class EmpMapper extends Mapper<Object, Text, Text, Text> {

@Override

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

throws IOException, InterruptedException {

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

String tmp = "";

while (tokenizer.hasMoreTokens()) {

tmp += tokenizer.nextToken().toString();

}

context.write(new Text("dept"), new Text(tmp));

}

}

public static class MulReducer extends Reducer<Object, Text, Text, Text> {

@Override

protected void reduce(Object key, Iterable<Text> value, Context context)

throws IOException, InterruptedException {

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

String tmp = "";

while (tokenizer.hasMoreTokens()) {

tmp += tokenizer.nextToken().toString() + "__";

}

context.write(new Text("emp"), new Text(tmp));

}

}

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

Configuration conf = new Configuration();

String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();

if (otherArgs.length != 3) {

System.out.println(otherArgs.length);

System.out.println("Usage: MultipleMapper <in> <in> <out>");

System.exit(2);

}

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

job.setJarByClass(MultipleMapper.class);

MultipleInputs.addInputPath(job, new Path(otherArgs[0]), TextInputFormat.class, DeptMapper.class);

MultipleInputs.addInputPath(job, new Path(otherArgs[1]), TextInputFormat.class, EmpMapper.class);

FileOutputFormat.setOutputPath(job, new Path(otherArgs[2]));

job.setCombinerClass(MulReducer.class);

job.setReducerClass(MulReducer.class);

job.setOutputFormatClass(TextOutputFormat.class);

job.setOutputKeyClass(Text.class);

job.setOutputValueClass(Text.class);

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

}

}