org.apache.hadoop.mapreduce.lib.output

Class NullOutputFormat<K,V>

java.lang.Object

org.apache.hadoop.mapreduce.OutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.NullOutputFormat<K,V>

@InterfaceAudience.Public
 @InterfaceStability.Stable
public class NullOutputFormat<K,V>
extends OutputFormat<K,V>

Consume all outputs and put them in /dev/null.

Constructor Summary

Constructors

Constructor and Description
NullOutputFormat()

Method Summary

Modifier and Type	Method and Description
void	checkOutputSpecs(JobContext context) Check for validity of the output-specification for the job.
OutputCommitter	getOutputCommitter(TaskAttemptContext context) Get the output committer for this output format.
RecordWriter<K,V>	getRecordWriter(TaskAttemptContext context) Get the RecordWriter for the given task.

Methods inherited from class java.lang.Object

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

Constructor Detail

NullOutputFormat

public NullOutputFormat()

Method Detail

getRecordWriter

public RecordWriter<K,V> getRecordWriter(TaskAttemptContext context)

Description copied from class: OutputFormat

Get the RecordWriter for the given task.

Specified by:

getRecordWriter in class OutputFormat<K,V>

Parameters:

context - the information about the current task.

Returns:

a RecordWriter to write the output for the job.

checkOutputSpecs

public void checkOutputSpecs(JobContext context)

Description copied from class: OutputFormat

Check for validity of the output-specification for the job.

This is to validate the output specification for the job when it is a job is submitted. Typically checks that it does not already exist, throwing an exception when it already exists, so that output is not overwritten.

Implementations which write to filesystems which support delegation tokens usually collect the tokens for the destination path(s) and attach them to the job context's JobConf.

Specified by:

checkOutputSpecs in class OutputFormat<K,V>

Parameters:

context - information about the job

getOutputCommitter

public OutputCommitter getOutputCommitter(TaskAttemptContext context)

Description copied from class: OutputFormat

Get the output committer for this output format. This is responsible for ensuring the output is committed correctly.

Specified by:

getOutputCommitter in class OutputFormat<K,V>

Parameters:

context - the task context

Returns:

an output committer