org.apache.tez.runtime.library.api

Class KeyValueReader

java.lang.Object

org.apache.tez.runtime.api.Reader

org.apache.tez.runtime.library.api.KeyValueReader

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public abstract class KeyValueReader
extends org.apache.tez.runtime.api.Reader

A key/value(s) pair based Reader. Example usage while (kvReader.next()) { Object key = kvReader.getCurrentKey(); Object value = kvReader.getCurrentValue(); if next() is called after processing everything, IOException would be thrown

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	completedProcessing

Constructor Summary

Constructors

Constructor and Description
KeyValueReader()

Method Summary

Modifier and Type	Method and Description
abstract Object	getCurrentKey() Returns the current key
abstract Object	getCurrentValue() Returns the current value
protected void	hasCompletedProcessing() Check whether processing has been completed.
abstract boolean	next() Moves to the next key/values(s) pair

Methods inherited from class java.lang.Object

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

Field Detail

completedProcessing

protected boolean completedProcessing

Constructor Detail

KeyValueReader

public KeyValueReader()

Method Detail

next

public abstract boolean next()
                      throws IOException

Moves to the next key/values(s) pair

Returns:

true if another key/value(s) pair exists, false if there are no more.

Throws:

IOException - if an error occurs

{@link - IOInterruptedException} if IO was performing a blocking operation and was interrupted

getCurrentKey

public abstract Object getCurrentKey()
                              throws IOException

Returns the current key

Returns:

the current key

Throws:

IOException

getCurrentValue

public abstract Object getCurrentValue()
                                throws IOException

Returns the current value

Returns:

the current value

Throws:

IOException

hasCompletedProcessing

protected void hasCompletedProcessing()
                               throws IOException

Check whether processing has been completed.

Throws:

IOException