替代hadoop减速器

Question

Iam a beginner to hadoop. I decided to create a sentiment analysis program .I have a mapper class. Output of the mapper is LongWritable and Text format. which is input to the reducer. Hence i have a reducer class as

public class sentreducer extends Reducer<LongWritable,Text,LongWritable,Text>{
          @Override
            public void reduce(LongWritable key,Iterable<Text>value,Context context){
            }   

Compiler shows an error saying that the method cannot be overriden. Why is that so?

Answer 1

the method signature should be

public void reduce(LongWritable key, Iterator<Text> values,
        OutputCollector<LongWritable, Text> collector, Reporter reporter) throws IOException 

Answer 2

I think you must be throwing a IOException and InterruptedException in your reduce method ie

public class sentreducer extends Reducer<LongWritable,Text,LongWritable,Text>{
    @Override
    public void reduce(LongWritable key,Iterable<Text> value,Context context) throws IOException, InterruptedException {
    }
}