Java8学习笔记_实例1

1）集合排序

Collections.sort(inventory, new Comparator<Apple>() {

  public int compare(Apple a1, Apple a2){

    return a1.getWeight().compareTo(a2.getWeight());

  }

});

inventory.sort(comparing(Apple::getWeight));

2）要筛选一个目录中的所有隐藏文件

File[] hiddenFiles = new File(".").listFiles(new FileFilter() {

public boolean accept(File file) {

return file.isHidden();

}

});

File[] hiddenFiles = new File(".").listFiles(File::isHidden);

3）集合过滤

仅仅选出绿苹果

public static List<Apple> filterGreenApples(List<Apple> inventory){

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

for (Apple apple: inventory){

if ("green".equals(apple.getColor())) {

result.add(apple);

}

}

return result;

}

List<Apple> inventory = Arrays.asList(new Apple(80,"green"),
                                      new Apple(155, "green"),
                                      new Apple(120, "red"));  

// [Apple{color=‘green‘, weight=80}, Apple{color=‘green‘, weight=155}]
List<Apple> greenApples = filterApples(inventory, FilteringApples::isGreenApple);
System.out.println(greenApples);

仅仅选出重的苹果

Java8学习笔记_实例1

原文：http://www.cnblogs.com/mjzhang/p/7652319.html