org.apache.hadoop.mapred
Interface OutputFormat

All Known Implementing Classes:

MapFileOutputFormat, NullOutputFormat, OutputFormatBase, SequenceFileOutputFormat, StreamOutputFormat, TextOutputFormat

public interface OutputFormat

An output data format. Output files are stored in a FileSystem.

Method Summary

void	checkOutputSpecs(FileSystem ignored, JobConf job) Check whether the output specification for a job is appropriate.
RecordWriter	getRecordWriter(FileSystem ignored, JobConf job, String name, Progressable progress) Construct a RecordWriter with Progressable.

Method Detail

getRecordWriter

RecordWriter getRecordWriter(FileSystem ignored,
                             JobConf job,
                             String name,
                             Progressable progress)
                             throws IOException

Construct a RecordWriter with Progressable.

Parameters:

job - the job whose output is being written

name - the unique name for this part of the output

progress - mechanism for reporting progress while writing to file

Returns:

a RecordWriter

Throws:

IOException

checkOutputSpecs

void checkOutputSpecs(FileSystem ignored,
                      JobConf job)
                      throws IOException

Check whether the output specification for a job is appropriate. Called when 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.

Parameters:

job - the job whose output will be written

Throws:

IOException - when output should not be attempted