org.apache.hadoop.examples

Class MultiFileWordCount.CombineFileLineRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

org.apache.hadoop.examples.MultiFileWordCount.CombineFileLineRecordReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Enclosing class:

MultiFileWordCount

public static class MultiFileWordCount.CombineFileLineRecordReader
extends RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

RecordReader is responsible from extracting records from a chunk of the CombineFileSplit.

Constructor Summary

Constructors

Constructor and Description
MultiFileWordCount.CombineFileLineRecordReader(CombineFileSplit split, TaskAttemptContext context, java.lang.Integer index)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the record reader.
MultiFileWordCount.WordOffset	getCurrentKey() Get the current key
org.apache.hadoop.io.Text	getCurrentValue() Get the current value.
float	getProgress() The current progress of the record reader through its data.
void	initialize(InputSplit split, TaskAttemptContext context) Called once at initialization.
boolean	nextKeyValue() Read the next key, value pair.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiFileWordCount.CombineFileLineRecordReader

public MultiFileWordCount.CombineFileLineRecordReader(CombineFileSplit split,
                                              TaskAttemptContext context,
                                              java.lang.Integer index)
                                               throws java.io.IOException

Throws:

java.io.IOException

Method Detail

initialize

public void initialize(InputSplit split,
              TaskAttemptContext context)
                throws java.io.IOException,
                       java.lang.InterruptedException

Description copied from class: RecordReader

Called once at initialization.

Specified by:

initialize in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Parameters:

split - the split that defines the range of records to read

context - the information about the task

Throws:

java.io.IOException

java.lang.InterruptedException

close

public void close()
           throws java.io.IOException

Description copied from class: RecordReader

Close the record reader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Throws:

java.io.IOException

getProgress

public float getProgress()
                  throws java.io.IOException

Description copied from class: RecordReader

The current progress of the record reader through its data.

Specified by:

getProgress in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Returns:

a number between 0.0 and 1.0 that is the fraction of the data read

Throws:

java.io.IOException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException

Description copied from class: RecordReader

Read the next key, value pair.

Specified by:

nextKeyValue in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Returns:

true if a key/value pair was read

Throws:

java.io.IOException

getCurrentKey

public MultiFileWordCount.WordOffset getCurrentKey()
                                            throws java.io.IOException,
                                                   java.lang.InterruptedException

Description copied from class: RecordReader

Get the current key

Specified by:

getCurrentKey in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Returns:

the current key or null if there is no current key

Throws:

java.io.IOException

java.lang.InterruptedException

getCurrentValue

public org.apache.hadoop.io.Text getCurrentValue()
                                          throws java.io.IOException,
                                                 java.lang.InterruptedException

Description copied from class: RecordReader

Get the current value.

Specified by:

getCurrentValue in class RecordReader<MultiFileWordCount.WordOffset,org.apache.hadoop.io.Text>

Returns:

the object that was read

Throws:

java.io.IOException

java.lang.InterruptedException