Class KeyValueTextInputFormat

  extended by org.apache.hadoop.mapreduce.InputFormat<K,V>
      extended by org.apache.hadoop.mapreduce.lib.input.FileInputFormat<Text,Text>
          extended by org.apache.hadoop.mapreduce.lib.input.KeyValueTextInputFormat

public class KeyValueTextInputFormat
extends FileInputFormat<Text,Text>

An InputFormat for plain text files. Files are broken into lines. Either line feed 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.

Nested Class Summary
Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat
Constructor Summary
Method Summary
 RecordReader<Text,Text> createRecordReader(InputSplit genericSplit, TaskAttemptContext context)
          Create a record reader for a given split.
protected  boolean isSplitable(JobContext context, Path file)
          Is the given filename splitable? Usually, true, but if the file is stream compressed, it will not be.
Methods inherited from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat
addInputPath, addInputPaths, computeSplitSize, getBlockIndex, getFormatMinSplitSize, getInputPathFilter, getInputPaths, getMaxSplitSize, getMinSplitSize, getSplits, listStatus, setInputPathFilter, setInputPaths, setInputPaths, setMaxInputSplitSize, setMinInputSplitSize
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public KeyValueTextInputFormat()
Method Detail


protected boolean isSplitable(JobContext context,
                              Path file)
Description copied from class: FileInputFormat
Is the given filename splitable? Usually, true, but if the file is stream compressed, it will not be. FileInputFormat implementations can override this and return false to ensure that individual input files are never split-up so that Mappers process entire files.

isSplitable in class FileInputFormat<Text,Text>
context - the job context
file - the file name to check
is this file splitable?


public RecordReader<Text,Text> createRecordReader(InputSplit genericSplit,
                                                  TaskAttemptContext context)
                                           throws IOException
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<Text,Text>
genericSplit - the split to be read
context - the information about the task
a new record reader

Copyright © 2009 The Apache Software Foundation