org.apache.hadoop.io

Class ArrayWritable

java.lang.Object

org.apache.hadoop.io.ArrayWritable

All Implemented Interfaces:

Writable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class ArrayWritable
extends Object
implements Writable

A Writable for arrays containing instances of a class. The elements of this writable must all be instances of the same class. If this writable will be the input for a Reducer, you will need to create a subclass that sets the value to be of the proper type. For example: public class IntArrayWritable extends ArrayWritable { public IntArrayWritable() { super(IntWritable.class); } }

Constructor Summary

Constructors

Constructor and Description
ArrayWritable(Class<? extends Writable> valueClass)
ArrayWritable(Class<? extends Writable> valueClass, Writable[] values)
ArrayWritable(String[] strings)

Method Summary

Methods

Modifier and Type	Method and Description
Writable[]	get()
Class	getValueClass()
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	set(Writable[] values)
Object	toArray()
String[]	toStrings()
void	write(DataOutput out) Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayWritable

public ArrayWritable(Class<? extends Writable> valueClass)

ArrayWritable

public ArrayWritable(Class<? extends Writable> valueClass,
             Writable[] values)

ArrayWritable

public ArrayWritable(String[] strings)

Method Detail

getValueClass

public Class getValueClass()

toStrings

public String[] toStrings()

toArray

public Object toArray()

set

public void set(Writable[] values)

get

public Writable[] get()

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException