com.google.appengine.tools.mapreduce.outputs

Class NoOutput<O,R>

java.lang.Object

com.google.appengine.tools.mapreduce.Output<O,R>

com.google.appengine.tools.mapreduce.outputs.NoOutput<O,R>

Type Parameters:

O - type of output values formally (but not actually) accepted by this output

R - type of result formally returned accepted by this output (though always return null)

All Implemented Interfaces:

Serializable

public class NoOutput<O,R>
extends Output<O,R>

An Output that throws an exception whenever an attempt is made to write a value.

Author:

ohler@google.com (Christian Ohler)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NoOutput()

Method Summary

Methods

Modifier and Type	Method and Description
List<? extends OutputWriter<O>>	createWriters(int numShards) Returns a list of writers, one for each shard, for this output.
R	finish(Collection<? extends OutputWriter<O>> writers) Returns null.

Methods inherited from class com.google.appengine.tools.mapreduce.Output

getContext, setContext

Methods inherited from class java.lang.Object

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

Constructor Detail

NoOutput

public NoOutput()

Method Detail

createWriters

public List<? extends OutputWriter<O>> createWriters(int numShards)

Description copied from class: Output

Returns a list of writers, one for each shard, for this output.

Specified by:

createWriters in class Output<O,R>

Parameters:

numShards - The number of shards which should be equal to the number of OutputWriters returned.

finish

public R finish(Collection<? extends OutputWriter<O>> writers)

Returns null.

Specified by:

finish in class Output<O,R>