org.apache.hadoop.io
Class NullWritable

java.lang.Object
  extended by org.apache.hadoop.io.NullWritable
All Implemented Interfaces:
Comparable<NullWritable>, Writable, WritableComparable<NullWritable>

@InterfaceAudience.Public
@InterfaceStability.Stable
public class NullWritable
extends Object
implements WritableComparable<NullWritable>

Singleton Writable with no data.


Method Summary
 int compareTo(NullWritable 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(NullWritable other)
Specified by:
compareTo in interface Comparable<NullWritable>

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


Copyright © 2012 Apache Software Foundation. All Rights Reserved.