org.apache.hadoop.mapred.lib

Class DelegatingInputFormat<K,V>

java.lang.Object

org.apache.hadoop.mapred.lib.DelegatingInputFormat<K,V>

All Implemented Interfaces:

InputFormat<K,V>

public class DelegatingInputFormat<K,V>
extends java.lang.Object
implements InputFormat<K,V>

An InputFormat that delegates behaviour of paths to multiple other InputFormats.

See Also:

MultipleInputs.addInputPath(JobConf, Path, Class, Class)

Constructor Summary

Constructors

Constructor and Description
DelegatingInputFormat()

Method Summary

Methods

Modifier and Type	Method and Description
RecordReader<K,V>	getRecordReader(InputSplit split, JobConf conf, Reporter reporter) Get the RecordReader for the given InputSplit.
InputSplit[]	getSplits(JobConf conf, int numSplits) Logically split the set of input files for the job.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingInputFormat

public DelegatingInputFormat()

Method Detail

getSplits

public InputSplit[] getSplits(JobConf conf,
                     int numSplits)
                       throws java.io.IOException

Description copied from interface: InputFormat

Logically split the set of input files for the job.

Each InputSplit is then assigned to an individual Mapper for processing.

Note: The split is a logical split of the inputs and the input files are not physically split into chunks. For e.g. a split could be <input-file-path, start, offset> tuple.

Specified by:

getSplits in interface InputFormat<K,V>

Parameters:

conf - job configuration.

numSplits - the desired number of splits, a hint.

Returns:

an array of InputSplits for the job.

Throws:

java.io.IOException

getRecordReader

public RecordReader<K,V> getRecordReader(InputSplit split,
                                JobConf conf,
                                Reporter reporter)
                                  throws java.io.IOException

Description copied from interface: InputFormat

Get the RecordReader for the given InputSplit.

It is the responsibility of the RecordReader to respect record boundaries while processing the logical split to present a record-oriented view to the individual task.

Specified by:

getRecordReader in interface InputFormat<K,V>

Parameters:

split - the InputSplit

conf - the job that this split belongs to

Returns:

a RecordReader

Throws:

java.io.IOException