Java8新特性

/**
 * @author mapleins
 * @Date 2018-12-12 12:31
 * @Desc 苹果的pojo 颜色、重量
 **/
public class Apple {

    private String color;

    private Long weight;
}

    /**
     * 找到绿色的苹果
     */
    public static List<Apple> findGreenApple(List<Apple> apples){
        List<Apple> list = new ArrayList<>();
        for (Apple apple : apples) {
            if("green".equals(apple.getColor())){
                list.add(apple);
            }
        }
        return list;
    }

    public static void main(String[] args) {
        List<Apple> list = Arrays.asList(new Apple("green",150l),
                new Apple("red",120l),new Apple("green",170l));
        List<Apple> greenApples = findGreenApple(list);
        System.out.println(greenApples);
    }

  结果：[Apple{color=‘green‘, weight=150}, Apple{color=‘green‘, weight=170}]

    /**
     * 通用的方法，我们传入苹果集合的同时，传入需要找到的苹果的颜色
     */
    public static List<Apple> findApple(List<Apple> apples,String color){
        List<Apple> list = new ArrayList<>();
        for (Apple apple : apples) {
            if(color.equals(apple.getColor())){
                list.add(apple);
            }
        }
        return list;
    }

    public static void main(String[] args) {
        List<Apple> list = Arrays.asList(new Apple("green",150l),new Apple("red",120l),new Apple("green",170l));
        List<Apple> apples = findApple(list, "red");
        System.out.println(apples);
    }
    结果：[Apple{color=‘red‘, weight=120}]

//1.定义过滤接口
/**
 * @author mapleins
 * @Date 2018-12-12 13:09
 * @Desc 过滤接口
 **/
public interface AppFilter {

    boolean filter(Apple apple);
    
}

//2.定义方法
    /**
     * 找到apple的方法
     */
public static List<Apple> findApple(List<Apple> apples,AppFilter appFilter){
     List<Apple> list = new ArrayList<>();
     for (Apple apple : apples) {
        if(appFilter.filter(apple)){
            list.add(apple);
        }
    }
    return list;
}

//3.测试
    public static void main(String[] args) {
        List<Apple> list = Arrays.asList(new Apple("green",150l),new Apple("red",120l),new Apple("green",140l));
        //找到红色，并且重量大于100的苹果
        List<Apple> apples = findApple(list, new AppFilter() {
            @Override
            public boolean filter(Apple apple) {
                return ("red".equals(apple.getColor()) && apple.getWeight() > 100l);
            }
        });
        System.out.println(apples);
    }

//4.结果
[Apple{color=‘red‘, weight=120}]

@FunctionalInterface //告诉编译器这是个函数式接口
public interface AppFilter {

    boolean filter(Apple apple);

}

/**
 * @author mapleins
 * @Date 2018-12-12 13:10
 * @Desc 通过策略模式，采用lambda表达式
 **/
public class AppFilter3 {

    public static void main(String[] args) {
        List<Apple> list = Arrays.asList(new Apple("green",150l),new Apple("red",120l),new Apple("green",140l));
        //找到红色，并且重量大于100的苹果
        List<Apple> apples = AppFilter2.findApple(list, apple -> {
            return "red".equals(apple.getColor()) && apple.getWeight() > 100;
        });
        System.out.println(apples);
    }

}

/**
 * @author mapleins
 * @Date 2018-12-12 13:34
 * @Desc 创建线程的方式
 **/
public class SetupThread {

    public static void main(String[] args) {
        //1.使用匿名内部类
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getName());
            }
        }).start();

        //2.lambda表达式
        new Thread(()-> System.out.println(Thread.currentThread().getName())).start();
    }
}