org.apache.hadoop.mapred.lib
Class IdentityMapper<K,V>

java.lang.Object
  extended by org.apache.hadoop.mapred.MapReduceBase
      extended by org.apache.hadoop.mapred.lib.IdentityMapper<K,V>
All Implemented Interfaces:
Closeable, JobConfigurable, Mapper<K,V,K,V>

@InterfaceAudience.Public
@InterfaceStability.Stable
public class IdentityMapper<K,V>
extends MapReduceBase
implements Mapper<K,V,K,V>

Implements the identity function, mapping inputs directly to outputs.


Constructor Summary
IdentityMapper()
           
 
Method Summary
 void map(K key, V val, OutputCollector<K,V> output, Reporter reporter)
          The identify function.
 
Methods inherited from class org.apache.hadoop.mapred.MapReduceBase
close, configure
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.apache.hadoop.mapred.JobConfigurable
configure
 
Methods inherited from interface java.io.Closeable
close
 

Constructor Detail

IdentityMapper

public IdentityMapper()
Method Detail

map

public void map(K key,
                V val,
                OutputCollector<K,V> output,
                Reporter reporter)
         throws IOException
The identify function. Input key/value pair is written directly to output.

Specified by:
map in interface Mapper<K,V,K,V>
Parameters:
key - the input key.
val - the input value.
output - collects mapped keys and values.
reporter - facility to report progress.
Throws:
IOException


Copyright © 2012 Apache Software Foundation. All Rights Reserved.