org.apache.hadoop.mapreduce.lib.input

Class SequenceFileAsTextRecordReader

java.lang.Object

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

org.apache.hadoop.mapreduce.lib.input.SequenceFileAsTextRecordReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class SequenceFileAsTextRecordReader
extends RecordReader<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

This class converts the input keys and values to their String forms by calling toString() method. This class to SequenceFileAsTextInputFormat class is as LineRecordReader class to TextInputFormat class.

Constructor Summary

Constructors

Constructor and Description
SequenceFileAsTextRecordReader()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the record reader.
org.apache.hadoop.io.Text	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 key/value pair in a line.

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceFileAsTextRecordReader

public SequenceFileAsTextRecordReader()
                               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<org.apache.hadoop.io.Text,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

getCurrentKey

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

Description copied from class: RecordReader

Get the current key

Specified by:

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

Returns:

the object that was read

Throws:

java.io.IOException

java.lang.InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException,
                            java.lang.InterruptedException

Read key/value pair in a line.

Specified by:

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

Returns:

true if a key/value pair was read

Throws:

java.io.IOException

java.lang.InterruptedException

getProgress

public float getProgress()
                  throws java.io.IOException,
                         java.lang.InterruptedException

Description copied from class: RecordReader

The current progress of the record reader through its data.

Specified by:

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

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<org.apache.hadoop.io.Text,org.apache.hadoop.io.Text>

Throws:

java.io.IOException