org.apache.hadoop.mapreduce.lib.input

Class DelegatingInputFormat<K,V>

java.lang.Object

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

org.apache.hadoop.mapreduce.lib.input.DelegatingInputFormat<K,V>

public class DelegatingInputFormat<K,V>
extends InputFormat<K,V>

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

See Also:

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

Constructor Summary

Constructors

Constructor and Description
DelegatingInputFormat()

Method Summary

Methods

Modifier and Type	Method and Description
RecordReader<K,V>	createRecordReader(InputSplit split, TaskAttemptContext context) Create a record reader for a given split.
java.util.List<InputSplit>	getSplits(JobContext job) 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 java.util.List<InputSplit> getSplits(JobContext job)
                                     throws java.io.IOException,
                                            java.lang.InterruptedException

Description copied from class: 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. The InputFormat also creates the RecordReader to read the InputSplit.

Specified by:

getSplits in class InputFormat<K,V>

Parameters:

job - job configuration.

Returns:

an array of InputSplits for the job.

Throws:

java.io.IOException

java.lang.InterruptedException

createRecordReader

public RecordReader<K,V> createRecordReader(InputSplit split,
                                   TaskAttemptContext context)
                                     throws java.io.IOException,
                                            java.lang.InterruptedException

Description copied from class: InputFormat

Create a record reader for a given split. The framework will call RecordReader.initialize(InputSplit, TaskAttemptContext) before the split is used.

Specified by:

createRecordReader in class InputFormat<K,V>

Parameters:

split - the split to be read

context - the information about the task

Returns:

a new record reader

Throws:

java.io.IOException

java.lang.InterruptedException