org.apache.hadoop.io
Class ArrayWritable

java.lang.Object
  extended by org.apache.hadoop.io.ArrayWritable
All Implemented Interfaces:
Writable

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
ArrayWritable(Class<? extends Writable> valueClass)
           
ArrayWritable(Class<? extends Writable> valueClass, Writable[] values)
           
ArrayWritable(String[] strings)
           
 
Method Summary
 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


Copyright © 2009 The Apache Software Foundation