org.apache.hadoop.mapreduce.lib.input
Class TextInputFormat

java.lang.Object
  org.apache.hadoop.mapreduce.InputFormat<K,V>
      org.apache.hadoop.mapreduce.lib.input.FileInputFormat<LongWritable,Text>
          org.apache.hadoop.mapreduce.lib.input.TextInputFormat

@InterfaceAudience.Public
@InterfaceStability.Stable
public class TextInputFormat
extends FileInputFormat<LongWritable,Text>

An InputFormat for plain text files. Files are broken into lines. Either linefeed or carriage-return are used to signal end of line. Keys are the position in the file, and values are the line of text..

Field Summary

Fields inherited from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat

DEFAULT_LIST_STATUS_NUM_THREADS, INPUT_DIR, INPUT_DIR_RECURSIVE, LIST_STATUS_NUM_THREADS, NUM_INPUT_FILES, PATHFILTER_CLASS, SPLIT_MAXSIZE, SPLIT_MINSIZE

Constructor Summary

TextInputFormat()

Method Summary

RecordReader<LongWritable,Text>	createRecordReader(InputSplit split, 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, addInputPathRecursively, addInputPaths, computeSplitSize, getBlockIndex, getFormatMinSplitSize, getInputDirRecursive, getInputPathFilter, getInputPaths, getMaxSplitSize, getMinSplitSize, getSplits, listStatus, makeSplit, makeSplit, setInputDirRecursive, 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

TextInputFormat

public TextInputFormat()

Method Detail

createRecordReader

public RecordReader<LongWritable,Text> createRecordReader(InputSplit split,
                                                          TaskAttemptContext context)

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<LongWritable,Text>

Parameters:

split - the split to be read

context - the information about the task

Returns:

a new record reader

isSplitable

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.

Overrides:

isSplitable in class FileInputFormat<LongWritable,Text>

Parameters:

context - the job context

file - the file name to check

Returns:

is this file splitable?