what is the right way to create a Writable class?

[juber patel <ju...@gmail.com>]

Hello,

I am using Hadoop 0.20.2 with the new mapreduce API. I have a class
that will be used as a value to mapper/reducer. I have implemented
Writable as follows, but I am not sure this is the right way. Could
someone please tell me how to do it when some ints, some int[] and
other proper objects like java.util.BitSet are involved?

All the examples I have seen deal with native Writables or primitives.


/**
 *
 */

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.BitSet;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.ObjectWritable;
import org.apache.hadoop.io.Writable;

public class Data implements Writable
{
	
	public static Configuration conf;

	
	public BitSet b;

	public BitSet rb;

	public int[] c;

	public int bNullPosition;

	public int rbNullPosition;
	
	
	/**
	 * writable must have empty constructor
	 */
	public Data()
	{
		b = new BitSet();
		rb = new BitSet();
				
	}

	public Data(BitSet b, BitSet rb, int[] c, int bNullPosition,
			int rbNullPositionl)
	{
		this.b = b;
		this.rb = rb;
		this.c = c;
		this.bNullPosition = bNullPosition;
		this.rbNullPosition = rbNullPosition;
	}
	
	@Override
	public void readFields(DataInput in) throws IOException
	{
		ObjectWritable bWritable = new ObjectWritable(BitSet.class, b);
		bWritable.readFields(in);
		bWritable = new ObjectWritable(BitSet.class, rb);
		bWritable.readFields(in);
		bWritable = null;
		
		c = (int[]) ObjectWritable.readObject(in, conf);
		
		bNullPosition = in.readInt();
		rbNullPosition = in.readInt();
		
		
	}

	@Override
	public void write(DataOutput out) throws IOException
	{
		ObjectWritable bWritable = new ObjectWritable(BitSet.class, b);
		bWritable.write(out);
		bWritable = new ObjectWritable(BitSet.class, rb);
		bWritable.write(out);
		bWritable = null;
		
		ObjectWritable.writeObject(out, c, int[].class, conf);
		out.writeInt(bNullPosition);
		out.writeInt(rbNullPosition);
		
			
	}
	
}