org.apache.hadoop.mapred

Class KeyValueTextInputFormat

java.lang.Object

org.apache.hadoop.mapred.FileInputFormat<Text,Text>

org.apache.hadoop.mapred.KeyValueTextInputFormat

All Implemented Interfaces:

InputFormat<Text,Text>, JobConfigurable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class KeyValueTextInputFormat
extends FileInputFormat<Text,Text>
implements JobConfigurable

An InputFormat for plain text files. Files are broken into lines. Either linefeed or carriage-return are used to signal end of line. Each line is divided into key and value parts by a separator byte. If no such a byte exists, the key will be the entire line and value will be empty.

Field Summary

Fields inherited from class org.apache.hadoop.mapred.FileInputFormat

INPUT_DIR_RECURSIVE, LOG, NUM_INPUT_FILES

Constructor Summary

Constructors

Constructor and Description
KeyValueTextInputFormat()

Method Summary

Methods

Modifier and Type	Method and Description
void	configure(JobConf conf) Initializes a new instance from a JobConf.
RecordReader<Text,Text>	getRecordReader(InputSplit genericSplit, JobConf job, Reporter reporter) Get the RecordReader for the given InputSplit.
protected boolean	isSplitable(FileSystem fs, Path file) Is the given filename splittable? Usually, true, but if the file is stream compressed, it will not be.

Methods inherited from class org.apache.hadoop.mapred.FileInputFormat

addInputPath, addInputPathRecursively, addInputPaths, computeSplitSize, getBlockIndex, getInputPathFilter, getInputPaths, getSplitHosts, getSplits, listStatus, makeSplit, makeSplit, setInputPathFilter, setInputPaths, setInputPaths, setMinSplitSize

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyValueTextInputFormat

public KeyValueTextInputFormat()

Method Detail

configure

public void configure(JobConf conf)

Description copied from interface: JobConfigurable

Initializes a new instance from a JobConf.

Specified by:

configure in interface JobConfigurable

Parameters:

conf - the configuration

isSplitable

protected boolean isSplitable(FileSystem fs,
                  Path file)

Description copied from class: FileInputFormat

Is the given filename splittable? Usually, true, but if the file is stream compressed, it will not be. The default implementation in FileInputFormat always returns true. Implementations that may deal with non-splittable files must override this method. FileInputFormat implementations can override this and return false to ensure that individual input files are never split-up so that Mappers process entire files.

Overrides:

isSplitable in class FileInputFormat<Text,Text>

Parameters:

fs - the file system that the file is on

file - the file name to check

Returns:

is this file splitable?

getRecordReader

public RecordReader<Text,Text> getRecordReader(InputSplit genericSplit,
                                      JobConf job,
                                      Reporter reporter)
                                        throws 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<Text,Text>

Specified by:

getRecordReader in class FileInputFormat<Text,Text>

Parameters:

genericSplit - the InputSplit

job - the job that this split belongs to

Returns:

a RecordReader

Throws:

IOException