de.hpi.fgis.voidgen.hadoop.tasks.inputstatistics
Class Task1Reducer

java.lang.Object
  extended by org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable>
      extended by de.hpi.fgis.voidgen.hadoop.tasks.inputstatistics.Task1Reducer

public class Task1Reducer
extends org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable>

Counts each distinct key.

Input

Output

Author:
Dandy Fenz, Hasso Plattner Institute at University of Potsdam, Germany, Matthias Pohl, Hasso Plattner Institute at University of Potsdam, Germany, Johannes Gosda, Hasso Plattner Institute at University of Potsdam, Germany

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Reducer
org.apache.hadoop.mapreduce.Reducer.Context
 
Constructor Summary
Task1Reducer()
           
 
Method Summary
 void reduce(org.apache.hadoop.io.Text key, java.lang.Iterable<org.apache.hadoop.io.NullWritable> values, org.apache.hadoop.mapreduce.Reducer.Context context)
           
 
Methods inherited from class org.apache.hadoop.mapreduce.Reducer
cleanup, run, setup
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Task1Reducer

public Task1Reducer()
Method Detail

reduce

public void reduce(org.apache.hadoop.io.Text key,
                   java.lang.Iterable<org.apache.hadoop.io.NullWritable> values,
                   org.apache.hadoop.mapreduce.Reducer.Context context)
            throws java.io.IOException,
                   java.lang.InterruptedException
Overrides:
reduce in class org.apache.hadoop.mapreduce.Reducer<org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.NullWritable>
Throws:
java.io.IOException
java.lang.InterruptedException