[ReactiveX Groovy] map & flatMap & concatMap sample ref: http://qiita.com/SHUAI/items/4b7d29b47919900d01bf

file0.groovy

numbers = Observable.from([1, 2, 3, 4, 5]);

numbers.map({it * it}).subscribe(
  { println(it); },                          // onNext
  { println("Error: " + it.getMessage()); }, // onError
  { println("Sequence complete"); }          // onCompleted
);

file1.txt

1
4
9
16
25
Sequence complete

file2.groovy

// this closure is an Observable that emits three numbers
numbers   = Observable.from([1, 2, 3]);
// this closure is an Observable that emits two numbers based on what number it is passed
multiples = { n -> Observable.from([ n*2, n*3 ]) };

numbers.flatMap(multiples).subscribe(
  { println(it); },                          // onNext
  { println("Error: " + it.getMessage()); }, // onError
  { println("Sequence complete"); }          // onCompleted
);

file3.txt

2
3
4
6
6
9
Sequence complete

file4.groovy

List<Integer> numbers;
Executor jobExecutor;

DataManager() {
    this.numbers = new ArrayList<>(Arrays.asList(2, 3, 4, 5, 6, 7, 8, 9, 10));
    this.jobExecutor = JobExecutor.getInstance();
}

Observable<Integer> squareOfAsync(int number) {
    return Observable.just(number * number).subscribeOn(Schedulers.from(this.jobExecutor));
}