对Mapreduce代码进行单元测试

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;

public class WordCount {

public static class TokenizerMapper

extends Mapper{

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 {

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

while (itr.hasMoreTokens()) {

word  = new Text(itr.nextToken()); //to unitest,should be new Text word.set(itr.nextToken())

context.write(word, new IntWritable(1));

}

}

}

public static class IntSumReducer

extends Reducer {

private IntWritable result = new IntWritable();

public void reduce(Text key, Iterable values,

Context context

) throws IOException, InterruptedException {

int sum = 0;

for (IntWritable val : values) {

sum += val.get();

}

result.set(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: wordcount  ");

System.exit(2);

}

Job job = new Job(conf, "word count");

job.setJarByClass(WordCount.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);

}

}

/* author zhouhh

* date:2012.8.7

*/

import static org.mockito.Mockito.*;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import org.apache.hadoop.io.*;

import org.junit.*;

public class WordCountTest {

@Test

public  void testWordCountMap() throws IOException, InterruptedException

{

WordCount w = new WordCount();

WordCount.TokenizerMapper mapper = new WordCount.TokenizerMapper();

Text value = new Text("a b c b a a");

@SuppressWarnings("unchecked")

WordCount.TokenizerMapper.Context context = mock(WordCount.TokenizerMapper.Context.class);

mapper.map(null, value, context);

verify(context,times(3)).write(new Text("a"), new IntWritable(1));

verify(context).write(new Text("c"), new IntWritable(1));

//verify(context).write(new Text("cc"), new IntWritable(1));

}

@Test

public void testWordCountReduce() throws IOException, InterruptedException

{

WordCount.IntSumReducer reducer = new WordCount.IntSumReducer();

WordCount.IntSumReducer.Context context = mock(WordCount.IntSumReducer.Context.class);

Text key = new Text("a");

List values = new ArrayList();

values.add(new IntWritable(1));

values.add(new IntWritable(1));

reducer.reduce(key, values, context);

verify(context).write(new Text("a"), new IntWritable(2));

}

public static void main(String[] args) {

// try {

// WordCountTest t = new WordCountTest();

//

// //t.testWordCountMap();

// t.testWordCountReduce();

// } catch (IOException e) {

// // TODO Auto-generated catch block

// e.printStackTrace();

// } catch (InterruptedException e) {

// // TODO Auto-generated catch block

// e.printStackTrace();

// }

}

}