Can I use MapWritable as a key?

[Choonho Son]

I am newbie.

Most of example shows that,
job.setOutputKeyClass(Text.class);

is it possible job.setOutputKeyClass(MapWritable.class);

because my key is combination of values(src IP, src Port, dst Port,
dst IP), so I want to use MapWritable as a key.

example code is like:

MapWritable mkey = new MapWritable();
MapWritable mval = new MapWritable();

mkey.put(new Text("sip"), new Text(array[3]));
mkey.put(new Text("sport"), new Text(array[5]));
mkey.put(new Text("proto"), new Text(array[7]));
mkey.put(new Text("dport"), new Text(array[6]));
mkey.put(new Text("dip"), new Text(array[4]));


mval.put(new Text("bcount"), new IntWritable(bcount));
mval.put(new Text("pcount"), new IntWritable(pcount));

context.write(mkey, mval);