To emulate a Mapper, flatMap() is exactly what you want. Since it flattens, it means you return an Iterable of values instead of 1 value. That can be a Collection containing many values, or 1, or 0.
For a reducer, to really reproduce what a Reducer does in Java, I think you will need groupByKey() followed by flatMapValues(). In many cases when I work with Map Reduce my mapper or my reducer might take a single value and map it to multiple keys - The reducer might also take a single key and emit multiple values I don't think that functions like flatMap and reduceByKey will work or are there tricks I am not aware of --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
