jpetitto

Observable.just("Hello, world!")
    .subscribe(new Action1<String>() {
        @Override
        public void call(String s) {
              System.out.println(s);
        }
});

Observable.just("Hello, world!")
    .subscribe(s -> System.out.println(s));

jpetitto

// no DI
public class Refrigerator {
  private PowerSource powerSource;
  
  public Refrigerator() {
    powerSource = new AcPowerSource();
  }
}

// with DI (manual)

jpetitto

public class MainActivity extends AppCompatActivity {
    private Fragment savedFragment;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState != null) {
            savedFragment = getSupportFragmentManager().getFragment(savedInstanceState, "content");

jpetitto

Enum<E extends Enum<E>> { ... }

<T extends Object & Comparable<? super T>> T Collections.max(Collection<? extends T>) { ... }

public <V extends Wrapper<? extends Comparable<T>>>
  Comparator<V> comparator() { ... }

error: equalTo(Box<capture of ?>) in Box<capture of ?> cannot be applied to (Box<capture of ?>)
  equal = unknownBox.equalTo(unknownBox)

jpetitto

for (int i = 0, remaining = 5; i < colorBucket.size() && remaining > 0; i++, remaining--) {
  ...
}

jpetitto

private <T> int picker(List<T> src, List<T> dst, int limit) {
  Iterator<T> iterator = src.iterator();
  while (iterator.hasNext() && limit > 0) {
    dst.add(iterator.next());
    limit--;
  }
  return limit;
}

jpetitto

List<Item> allBucket = ...
List<Item> genderBucket = ...
List<Item> sizeBucket = ...
List<Item> colorBucket = ...

List<Item> recommendations = new ArrayList<>();
picker(recommendations, limit, colorBucket, sizeBucket, genderBucket, allBucket);

private <T> int picker(List<T> src, List<T> dst, int limit) {
  Iterator<T> iterator = src.iterator();

jpetitto

BehaviorSubject<Integer> timerSubject = BehaviorSubject.create(1);

timerSubject
    .switchMap(interval -> Observable.timer(interval, TimeUnit.SECONDS, Schedulers.newThread()))
    .flatMap(i -> Observable.just(randomInt()))
    .doOnNext(timerSubject::onNext)
    .subscribe(System.out::println);

jpetitto

Observable.just(1, 2, 3, 4, 5)
        .groupBy(i -> i % 2 == 0 ? "even" : "odd")
        .subscribe(obs -> {
            if (obs.getKey().equals("even")) {
                obs.subscribe(i -> System.out.println("even: " + i));
            } else {
                obs.subscribe(i -> System.out.println("odd: " + i));
            }
        });

jpetitto

<android.support.v7.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="16dp"
    android:clipToPadding="false" />