run(Context context)
{
setup(context);
while (context.nextKeyValue())
{
map(context.getCurrentKey(), context.getCurrentValue(), context);
}
cleanup(context);
}
setup(Context context)
map(Writable key, Writable value, Context context)
cleanup(Context context)
{
setup(context);
while (context.nextKeyValue())
{
map(context.getCurrentKey(), context.getCurrentValue(), context);
}
cleanup(context);
}
setup(Context context)
map(Writable key, Writable value, Context context)
cleanup(Context context)
The
Mapper contains the run() method, which call its own setup() method only once, it also call a
map() method for each input and finally
calls it cleanup() method. We can override all above
methods in our code.
Each
of these methods can access the job’s configuration data by using Context.getConfiguration().
