Hadoop之MapReduce单元测试

public class WordCountMapper extends Mapper {
	private static final IntWritable one = new IntWritable(1);
	private Text word = new Text();
	@Override
	protected void map(LongWritable key, Text value,Context context)
			throws IOException, InterruptedException {
		String line = value.toString();		// 该行的内容
		String[] words = line.split(";");	// 解析该行的单词
		for(String w : words) {
			word.set(w);
			context.write(word,one);
		}
	}
}

public class WordCountReducer extends Reducer {
	@Override
	protected void reduce(Text key, Iterable values,Context context)
			throws IOException, InterruptedException {
		int sum = 0;
		Iterator iterator = values.iterator();		// key相同的值集合
		while(iterator.hasNext()) {
			int one = iterator.next().get();
			sum += one;
		}
		context.write(key, new IntWritable(sum));
	}
}

public class WordCountMapperReducerTest {
	@Test
	public void processValidRecord() throws IOException, InterruptedException {
		WordCountMapper mapper = new WordCountMapper();
		Text value = new Text("hello");
		org.apache.hadoop.mapreduce.Mapper.Context context = mock(Context.class);
		mapper.map(null, value, context);
		verify(context).write(new Text("hello"), new IntWritable(1));
	}
	@Test
	public void processResult() throws IOException, InterruptedException {
		WordCountReducer reducer = new WordCountReducer();
		Text key = new Text("hello");
		// {"hello",[1,1,2]}
		Iterable values = Arrays.asList(new IntWritable(1),new IntWritable(1),new IntWritable(2));
		org.apache.hadoop.mapreduce.Reducer.Context context = mock(org.apache.hadoop.mapreduce.Reducer.Context.class);
		reducer.reduce(key, values, context);
		verify(context).write(key, new IntWritable(4));		// {"hello",4}
	}
}