org.apache.hadoop.io
Class NullWritable

java.lang.Object
  org.apache.hadoop.io.NullWritable

All Implemented Interfaces:

Comparable, Writable, WritableComparable

public class NullWritable
extends Object
implements WritableComparable

Singleton Writable with no data.

Nested Class Summary

static class

NullWritable.Comparator A Comparator "optimized" for NullWritable.

Method Summary

int	compareTo(Object other)
boolean	equals(Object other)
static NullWritable	get() Returns the single instance of this class.
int	hashCode()
void	readFields(DataInput in) Deserialize the fields of this object from in.
String	toString()
void	write(DataOutput out) Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

get

public static NullWritable get()

Returns the single instance of this class.

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

compareTo

public int compareTo(Object other)

Specified by:

compareTo in interface Comparable

equals

public boolean equals(Object other)

Overrides:

equals in class Object

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