org.apache.avro.mapred

Class AvroReducer<K,V,OUT>

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.avro.mapred.AvroReducer<K,V,OUT>

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.conf.Configurable, org.apache.hadoop.mapred.JobConfigurable

public class AvroReducer<K,V,OUT>
extends org.apache.hadoop.conf.Configured
implements org.apache.hadoop.mapred.JobConfigurable, Closeable

A reducer for Avro data.

Applications should subclass this class and pass their subclass to AvroJob.setReducerClass(JobConf, Class) and perhaps AvroJob.setCombinerClass(JobConf, Class). Subclasses override reduce(Object, Iterable, AvroCollector, Reporter).

Constructor Summary

Constructors

Constructor and Description
AvroReducer()

Method Summary

Modifier and Type	Method and Description
void	close() Subclasses can override this as desired.
void	configure(org.apache.hadoop.mapred.JobConf jobConf) Subclasses can override this as desired.
void	reduce(K key, Iterable<V> values, AvroCollector<OUT> collector, org.apache.hadoop.mapred.Reporter reporter) Called with all map output values with a given key.

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Constructor Detail

AvroReducer

public AvroReducer()

Method Detail

reduce

public void reduce(K key,
                   Iterable<V> values,
                   AvroCollector<OUT> collector,
                   org.apache.hadoop.mapred.Reporter reporter)
            throws IOException

Called with all map output values with a given key. By default, pairs key with each value, collecting Pair instances.

Throws:

IOException

close

public void close()
           throws IOException

Subclasses can override this as desired.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

configure

public void configure(org.apache.hadoop.mapred.JobConf jobConf)

Subclasses can override this as desired.

Specified by:

configure in interface org.apache.hadoop.mapred.JobConfigurable