SwitchRxSchedulers.java

import rx.Observable;
import rx.schedulers.Schedulers;

import java.util.List;


public class SwitchRxSchedulers {

  public static void main(String[] args) throws InterruptedException {
    final Object monitor = new Object();
    getStrings()
        .flatMap(Observable::from)
        .subscribeOn(Schedulers.io())
        .doOnNext(Main::printElementAndThread)
        .map(String::toUpperCase)
        .observeOn(Schedulers.computation())
        .doOnNext(Main::printElementAndThread)
        .map(String::toLowerCase)
        .observeOn(Schedulers.newThread())
        .subscribe(
            Main::printElementAndThread,
            t -> System.err.println(t.getMessage()),
            () -> {
              synchronized (monitor) {
                monitor.notifyAll();
              }
            }
        );

    synchronized (monitor) {
      monitor.wait();
    }
  }

  private static void printElementAndThread(String s) {
    System.out.printf("%s : %s%n", s, Thread.currentThread().getName());
  }

  private static Observable<List<String>> getStrings() {
    return Observable.range(0, 100)
        .map(i -> String.format("String #%d", i))
        .toList();
  }
}