实现List集合排序的两种方法（使用Collections.sort方法）

1：实现comparable

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class User implements Comparable<User> {

    private int score;

    private int age;

    public User(int score, int age) {
        super();
        this.score = score;
        this.age = age;
    }

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
    }

    public int getAge() {
        return age;
    }

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

    @Override
    public int compareTo(User o) {
        int i = this.getAge() - o.getAge();//先按照年龄排序
        if (i == 0) {
            return this.score - o.getScore();//如果年龄相等了再用分数进行排序
        }
        return i;
    }

    public static void main(String[] args) {
        List<User> users = new ArrayList<User>();
        users.add(new User(78, 26));
        users.add(new User(67, 23));
        users.add(new User(34, 56));
        users.add(new User(55, 23));
        Collections.sort(users);
        for (User user : users) {
            System.out.println(user.getScore() + "," + user.getAge());
        }
    }
}

  2 ：直接用匿名内部类

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class Students {

    private int age;
    private int score;

    public Students(int age, int score) {
        super();
        this.age = age;
        this.score = score;
    }

    public int getAge() {
        return age;
    }

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

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
    }

    public static void main(String[] args) {
        List<Students> students = new ArrayList<Students>();
        students.add(new Students(23, 100));
        students.add(new Students(27, 98));
        students.add(new Students(29, 99));
        students.add(new Students(29, 98));
        students.add(new Students(22, 89));
        Collections.sort(students, new Comparator<Students>() {

            @Override
            public int compare(Students o1, Students o2) {
                int i = o1.getScore() - o2.getScore();
                if (i == 0) {
                    return o1.getAge() - o2.getAge();
                }
                return i;
            }
        });
        for (Students stu : students) {
            System.out.println("score:" + stu.getScore() + ":age" + stu.getAge());
        }
    }
}