Java list排序的几种方式

使用流进行排序

	
/**
 * @description: 排序对象
 * @datetime 2023年 05月 08日 16:51
 * @version: 1.0
 */
public class Human {
    private String name;

    private int age;

    public Human() {
    }

    public Human(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

public class PaiXu {

    public static void main(String[] args) {
        ArrayList<Human> humans = new ArrayList<Human>() {
            {
                add(new Human("guorao", 10));
                add(new Human("mako", 12));
                add(new Human("hel", 30));
                add(new Human("lin", 28));
            }
        };
        // 倒叙
        //List collect = humans.stream().sorted(Comparator.comparingInt(Human::getAge).reversed()).collect(Collectors.toList());
        // 升序
        List<Human> collect = humans.stream().sorted(Comparator.comparingInt(Human::getAge)).collect(Collectors.toList());
        System.out.println("collect = " + JSON.toJSONString(collect));
    }


}

使用Collections 工具类排序

public class PaiXu {

    public static void main(String[] args) {
        //Collections 排序
        collectionsSort();
    }


    private static void collectionsSort() {
        ArrayList<Human> humans = new ArrayList<Human>() {
            {
                add(new Human("guorao", 10));
                add(new Human("mako", 12));
                add(new Human("hel", 30));
                add(new Human("lin", 28));
            }
        };

        // 自定义比较器
        //Collections.sort(humans, new Comparator(){
        //    //这样实现接口不用再专门写一格实现类了。
        //    public int compare(Human s1, Human s2) {
        //        // TODO 自动生成的方法存根
        //        return s1.getAge() - s2.getAge();//升序
        //        //return s2.getAge() - s1.getAge();//降序
        //    }
        //});
        Collections.sort(humans, Comparator.comparingInt(s -> s.getAge()));

        System.out.println("humans = " + JSON.toJSONString(humans));
    }


}