利用MultipleOutputs控制reduce输出路径

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package com.mr.test;import java.io.IOException;import java.util.Iterator;import java.util.StringTokenizer;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.mapred.FileInputFormat;import org.apache.hadoop.mapred.FileOutputFormat;import org.apache.hadoop.mapred.JobClient;import org.apache.hadoop.mapred.JobConf;import org.apache.hadoop.mapred.Mapper;import org.apache.hadoop.mapred.OutputCollector;import org.apache.hadoop.mapred.Reducer;import org.apache.hadoop.mapred.Reporter;import org.apache.hadoop.mapred.TextInputFormat;import org.apache.hadoop.mapred.TextOutputFormat;import org.apache.hadoop.mapred.lib.MultipleOutputs;public class WordCount {    public static class MyMap implements            Mapper<LongWritable, Text, Text, IntWritable> {        private final static IntWritable one = new IntWritable(1);        private Text word = new Text();                public void map(LongWritable key, Text value,                OutputCollector<Text, IntWritable> output, Reporter reporter)                throws IOException {            String line = value.toString();            StringTokenizer tokenizer = new StringTokenizer(line);            while (tokenizer.hasMoreTokens()) {                word.set(tokenizer.nextToken());                output.collect(word, one);            }        }public void configure(JobConf arg0) {}public void close() throws IOException {// TODO Auto-generated method stub}    }    public static class MyReduce implements            Reducer<Text, IntWritable, Text, IntWritable> {    private MultipleOutputs mos;    private JobConf jobconf;        public void reduce(Text key, Iterator<IntWritable> values,                OutputCollector<Text, IntWritable> output, Reporter reporter)                throws IOException {            int sum = 0;            while (values.hasNext()) {                sum += values.next().get();            }            mos.getCollector(key.toString(), reporter).collect(key, new IntWritable(sum));//            mos.getCollector(key.toString(),"test", reporter).collect(key, new IntWritable(sum));        }public void configure(JobConf jobconf) {mos = new MultipleOutputs(jobconf);this.jobconf = jobconf;}public void close() throws IOException {mos.close();}    }    public static void main(String[] args) throws Exception {        JobConf conf = new JobConf(WordCount.class);        conf.setJobName("wordcount");        conf.setOutputKeyClass(Text.class);        conf.setOutputValueClass(IntWritable.class);        conf.setMapperClass(MyMap.class);        conf.setCombinerClass(MyReduce.class);        conf.setReducerClass(MyReduce.class);        conf.setInputFormat(TextInputFormat.class);        conf.setOutputFormat(TextOutputFormat.class);System.out.println("args1:"+args[0]);System.out.println("args2:"+args[1]);        FileInputFormat.setInputPaths(conf, new Path(args[0]));        FileOutputFormat.setOutputPath(conf, new Path(args[1]));        MultipleOutputs.addNamedOutput(conf, "test1", TextOutputFormat.class,         LongWritable.class, Text.class);        MultipleOutputs.addNamedOutput(conf, "test2", TextOutputFormat.class,        LongWritable.class, Text.class);        MultipleOutputs.addNamedOutput(conf, "test3", TextOutputFormat.class,        LongWritable.class, Text.class);        MultipleOutputs.addNamedOutput(conf, "test4", TextOutputFormat.class,        LongWritable.class, Text.class);        MultipleOutputs.addNamedOutput(conf, "test5", TextOutputFormat.class,        LongWritable.class, Text.class);        JobClient.runJob(conf);    }}

input.txt:

test1
test2
test3
test4
test5

output:

-rw-r--r--   2 test supergroup          0 2014-04-20 11:23 /chukwa/output/0419-10/_SUCCESS
drwxr-xr-x   - test supergroup          0 2014-04-20 11:23 /chukwa/output/0419-10/_logs
-rw-r--r--   2 test supergroup         42 2014-04-20 11:23 /chukwa/output/0419-10/part-00000.lzo
-rw-r--r--   2 test supergroup         58 2014-04-20 11:23 /chukwa/output/0419-10/test1-m-00000.lzo
-rw-r--r--   2 test supergroup         58 2014-04-20 11:23 /chukwa/output/0419-10/test2-m-00000.lzo
-rw-r--r--   2 test supergroup         58 2014-04-20 11:23 /chukwa/output/0419-10/test3-m-00000.lzo
-rw-r--r--   2test supergroup         58 2014-04-20 11:23 /chukwa/output/0419-10/test4-m-00001.lzo
-rw-r--r--   2 test supergroup         58 2014-04-20 11:23 /chukwa/output/0419-10/test5-m-00001.lzo

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