Solution to https://projecteuler.net/problem=2 using Java8 streams/optionals

Fibo.java

import java.util.Arrays;
import java.util.stream.Stream;

public class Fibo {
	public static void main(String[] args) {
		Arrays
			.stream(args)
			.findFirst()
			.map(Long::parseLong)
			.map(Fibo::computeFiboSum)
			.ifPresent(System.out::println);
	}

	private static long computeFiboSum(long limit) {
		return Stream
			.iterate(new long[] {1, 2}, f -> new long[] {f[1], f[0]+f[1]})
			.limit(90)
			.mapToLong(f -> f[0])
			.filter(n -> n < limit)
			.filter(n -> n % 2 == 0)
			.sum();
	}
}