package com.brianway.learning.java8.lambda;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.function.Predicate;

/**

* Created by brian on 16/12/26.

*

* 传递代码的例子

* 分别使用了方法引用和Lambda(匿名函数)

*/

public class FilteringApples {

public static void main(String[] args) {

List<Apple> inventory = Arrays.asList(new Apple(80, "green"),

new Apple(155, "green"),

new Apple(120, "red"));

List<Apple> greenApples = filter(inventory, FilteringApples::isGreenApple);

System.out.println(greenApples);

List<Apple> greenApples2 = filter(inventory, (Apple a) -> "green".equals(a.getColor()));

System.out.println(greenApples2);

List<Apple> heavyApples = filter(inventory, FilteringApples::isHeavyApple);

System.out.println(heavyApples);

List<Apple> heavyApples2 = filter(inventory, (Apple a) -> a.getWeight() > 150);

System.out.println(heavyApples2);

}

/**

* 根据抽象条件筛选

* 将迭代集合的逻辑和要应用到集合中每个元素的行为区分开

*

* @param inventory

* @param p

* @return

*/

public static List<Apple> filter(List<Apple> inventory, Predicate<Apple> p) {

List<Apple> result = new ArrayList<>();

for (Apple apple : inventory) {

if (p.test(apple)) {

result.add(apple);

}

}

return result;

}

public static boolean isGreenApple(Apple apple) {

return "green".equals(apple.getColor());

}

public static boolean isHeavyApple(Apple apple) {

return apple.getWeight() > 150;

}

public static class Apple {

private int weight = 0;

private String color = "";

public Apple(int weight, String color) {

this.weight = weight;

this.color = color;

}

public Integer getWeight() {

return weight;

}

public void setWeight(Integer weight) {

this.weight = weight;

}

public String getColor() {

return color;

}

public void setColor(String color) {

this.color = color;

}

public String toString() {

return "Apple{" +

"color='" + color + '\'' +

", weight=" + weight +

'}';

}

}

}