Optional Observable

Optional.java

public class Optional<T> {
    Observable<T> obs;

    public Optional(Observable<T> obs) {
        this.obs = obs;
    }

    public static <T> Optional<T> of(T value) {
        if (value == null) {
            throw new NullPointerException();
        } else {
            return new Optional<T>(Observable.just(value));
        }
    }

    public static <T> Optional<T> ofNullable(T value) {
        if (value == null) {
            return empty();
        } else {
            return new Optional<T>(Observable.just(value));
        }
    }

    public T get() {
        return obs.toBlocking().single();
    }

    public T orElse(T defaultValue) {
        return obs.defaultIfEmpty(defaultValue).toBlocking().single();
    }

    public <R> Optional<R> map(Func1<T, R> func) {
        return Optional.ofNullable(func.call(get()));
    }

    public <R> Optional<R> flatMap(Func1<T, Optional<R>> func) {
        return func.call(get());
    }

    public static <T> Optional<T> empty() {
        return new Optional<T>(Observable.empty());
    }
}