Created
April 24, 2012 07:13
-
-
Save yongboy/2477347 to your computer and use it in GitHub Desktop.
WordCountTest.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
package com.hadoop.learn.test; | |
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; | |
import org.apache.hadoop.util.GenericOptionsParser; | |
import org.apache.log4j.Logger; | |
/** | |
* 运行测试程序 | |
* | |
* @author yongboy | |
* @date 2012-04-16 | |
*/ | |
public class WordCountTest { | |
private static final Logger log = Logger.getLogger(WordCountTest.class); | |
public static class TokenizerMapper 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 { | |
log.info("Map key : " + key); | |
log.info("Map value : " + value); | |
StringTokenizer itr = new StringTokenizer(value.toString()); | |
while (itr.hasMoreTokens()) { | |
String wordStr = itr.nextToken(); | |
word.set(wordStr); | |
log.info("Map word : " + wordStr); | |
context.write(word, one); | |
} | |
} | |
} | |
public static class IntSumReducer extends | |
Reducer<Text, IntWritable, Text, IntWritable> { | |
private IntWritable result = new IntWritable(); | |
public void reduce(Text key, Iterable<IntWritable> values, | |
Context context) throws IOException, InterruptedException { | |
log.info("Reduce key : " + key); | |
log.info("Reduce value : " + values); | |
int sum = 0; | |
for (IntWritable val : values) { | |
sum += val.get(); | |
} | |
result.set(sum); | |
log.info("Reduce sum : " + sum); | |
context.write(key, result); | |
} | |
} | |
public static void main(String[] args) throws Exception { | |
Configuration conf = new Configuration(); | |
String[] otherArgs = new GenericOptionsParser(conf, args) | |
.getRemainingArgs(); | |
if (otherArgs.length != 2) { | |
System.err.println("Usage: WordCountTest <in> <out>"); | |
System.exit(2); | |
} | |
Job job = new Job(conf, "word count"); | |
job.setJarByClass(WordCountTest.class); | |
job.setMapperClass(TokenizerMapper.class); | |
job.setCombinerClass(IntSumReducer.class); | |
job.setReducerClass(IntSumReducer.class); | |
job.setOutputKeyClass(Text.class); | |
job.setOutputValueClass(IntWritable.class); | |
FileInputFormat.addInputPath(job, new Path(otherArgs[0])); | |
FileOutputFormat.setOutputPath(job, new Path(otherArgs[1])); | |
System.exit(job.waitForCompletion(true) ? 0 : 1); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment