StreamSample.java

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.IntStream;

public class StreamSample {

	private static final int LIMIT = 4;

	public static void main(String[] args) {
		Supplier<Integer> supplier = () -> 5;
		Consumer<Integer> print = i -> System.out.println("consume " + i);
		Function<Integer, Integer> multiplyBy5 = i -> i * 5;
		Predicate<Integer> evenNumbers = i -> i % 2 == 0;
		Consumer<String> title = s -> System.out.println("\n" + s + "\n" + "---------------------------------");

		Integer[] array = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
		int count = 0;
		title.accept("Array For");
		for (int i = 0; i < array.length; i++) {
			int n = array[i];
			// Same lines of code
			n = multiplyBy5.apply(n);
			if (evenNumbers.test(n)) {
				print.accept(n);
				count++;
			}
			if (count >= LIMIT)
				break;
			//////////////////////
		}

		List<Integer> list = Arrays.asList(array);
		Iterator<Integer> iter = list.iterator();

		count = 0;
		title.accept("Iterator While");
		while (iter.hasNext()) {
			int n = iter.next();
			// Same lines of code
			n = multiplyBy5.apply(n);
			if (evenNumbers.test(n)) {
				print.accept(n);
				count++;
			}
			if (count >= LIMIT)
				break;
			//////////////////////
		}

		count = 0;
		title.accept("For Each");
		for (Integer n : list) {
			// Same lines of code
			n = multiplyBy5.apply(n);
			if (evenNumbers.test(n)) {
				print.accept(n);
				count++;
			}
			if (count >= LIMIT)
				break;
			//////////////////////
		}

		title.accept("Java 8 Stream");
		IntStream.range(0, 10).boxed().map(multiplyBy5).filter(evenNumbers).limit(LIMIT).forEach(print);

	}

}