Package org.apache.hadoop.streaming.io

Class OutputReader<K,V>

java.lang.Object

org.apache.hadoop.streaming.io.OutputReader<K,V>

Direct Known Subclasses:

KeyOnlyTextOutputReader, RawBytesOutputReader, TextOutputReader, TypedBytesOutputReader

public abstract class OutputReader<K,V>
extends java.lang.Object

Abstract base for classes that read the client's output.

Constructor Summary

Constructors

Constructor	Description
OutputReader()

Method Summary

Modifier and Type	Method	Description
abstract K	getCurrentKey()	Returns the current key.
abstract V	getCurrentValue()	Returns the current value.
abstract java.lang.String	getLastOutput()	Returns the last output from the client as a String.
void	initialize(PipeMapRed pipeMapRed)	Initializes the OutputReader.
abstract boolean	readKeyValue()	Read the next key/value pair outputted by the client.

Methods inherited from class java.lang.Object

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

Constructor Detail

OutputReader

public OutputReader()

Method Detail

initialize

public void initialize(PipeMapRed pipeMapRed)
                throws java.io.IOException

Initializes the OutputReader. This method has to be called before calling any of the other methods.

Throws:

java.io.IOException

readKeyValue

public abstract boolean readKeyValue()
                              throws java.io.IOException

Read the next key/value pair outputted by the client.

Returns:

true iff a key/value pair was read

Throws:

java.io.IOException

getCurrentKey

public abstract K getCurrentKey()
                         throws java.io.IOException

Returns the current key.

Throws:

java.io.IOException

getCurrentValue

public abstract V getCurrentValue()
                           throws java.io.IOException

Returns the current value.

Throws:

java.io.IOException

getLastOutput

public abstract java.lang.String getLastOutput()

Returns the last output from the client as a String.