oracle.hadoop.balancer.examples.movie

Class MovieGenre.MovieGenreReducer

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.Text>

oracle.hadoop.balancer.examples.movie.MovieGenre.MovieGenreReducer

Enclosing class:

MovieGenre

public static class MovieGenre.MovieGenreReducer
extends org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.Text>

Reducer class for movie-demo example. In each line, it list genre-id followed by a list of movie-ids.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer

org.apache.hadoop.mapreduce.Reducer.Context

Constructor Summary

Constructors

Constructor and Description
MovieGenre.MovieGenreReducer()

Method Summary

Methods

Modifier and Type	Method and Description
void	reduce(org.apache.hadoop.io.IntWritable genreID, java.lang.Iterable<org.apache.hadoop.io.IntWritable> movieIDs, org.apache.hadoop.mapreduce.Reducer.Context context) The reduce function.

Methods inherited from class org.apache.hadoop.mapreduce.Reducer

run

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MovieGenre.MovieGenreReducer

public MovieGenre.MovieGenreReducer()

Method Detail

reduce

public void reduce(org.apache.hadoop.io.IntWritable genreID,
          java.lang.Iterable<org.apache.hadoop.io.IntWritable> movieIDs,
          org.apache.hadoop.mapreduce.Reducer.Context context)
            throws java.io.IOException,
                   java.lang.InterruptedException

The reduce function. The output per line is:

• genre-id <list of movie-ids>

Overrides:

reduce in class org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.IntWritable,org.apache.hadoop.io.Text>

Throws:

java.io.IOException

java.lang.InterruptedException