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

java.lang.Object
  extended by org.apache.hadoop.mapreduce.OutputFormat<K,V>
      extended by org.apache.hadoop.mapreduce.lib.output.NullOutputFormat<K,V>

public class NullOutputFormat<K,V>
extends OutputFormat<K,V>

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


Constructor Summary
NullOutputFormat()
           
 
Method Summary
 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.

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


Copyright © 2009 The Apache Software Foundation