Laziness.java

package com.brianway.learning.java8.streamapi;

import static java.util.stream.Collectors.toList;

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

/**
 * 流操作-中间操作
 */
public class Laziness {

    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8);
        List<Integer> twoEvenSquares =
                numbers.stream()
                        .filter(n -> {
                            System.out.println("filtering " + n);
                            return n % 2 == 0;
                        })
                        .map(n -> {
                            System.out.println("mapping " + n);
                            return n * n;
                        })
                        .limit(2)
                        .collect(toList());

        twoEvenSquares.stream().forEach(System.out::println);
    }

}