ObservableVSIterator.java

package com.packtpub.reactive.chapter01;

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

import rx.Observable;
import rx.functions.Action0;
import rx.functions.Action1;

import com.packtpub.reactive.common.Program;

/**
 * Demonstrate the differences between Iterators and Observables.
 * 
 * @author meddle
 */
public class ObservableVSIterator implements Program {

	private static void usingIteratorExample() {
		List<String> list = Arrays
				.asList("One", "Two", "Three", "Four", "Five");

		Iterator<String> iterator = list.iterator();

		// While there is a next element, PULL it from the source and print it.
		while (iterator.hasNext()) {
			System.out.println(iterator.next());
		}
	}

	private static void usingObservableExample() {
		List<String> list = Arrays
				.asList("One", "Two", "Three", "Four", "Five");

		Observable<String> observable = Observable.from(list);
		
		// Subscribe to the Observable. It will PUSH it's values to the Subscriber, and it will be printed.
		observable.subscribe(new Action1<String>() {
			public void call(String element) {
				System.out.println(element);
			}
		}, new Action1<Throwable>() {
			public void call(Throwable t) {
				System.err.println(t); // (1)
			}
		}, new Action0() {
			public void call() {
				System.out.println("We've finnished!"); // (2)
			}
		});
	}

	@Override
	public String name() {
		return "Iterator vs Observable";
	}

	@Override
	public void run() {
		System.out.println("Running Iterator example:");
		usingIteratorExample();
		
		System.out.println("Running Observable example:");
		usingObservableExample();
	}

	@Override
	public int chapter() {
		return 1;
	}
	
	public static void main(String[] args) {
		new ObservableVSIterator().run();
	}
}