Java實現List自定義排序

廢話不多說，直接上代碼

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


public class User {
    
    
    public static void main(String[] args) {
        List<User> list = new ArrayList<>();
        list.add(new User("張三",18));
        list.add(new User("諸葛亮",69));
        list.add(new User("孫悟空",500));
        list.add(new User("周傑倫",45));
        list.add(new User("郭德綱",60));
        list.add(new User("秦始皇",5000));
        System.out.println("排序前：");
        System.out.println(list);
        Collections.sort(list, new Comparator<User>() {
            
            @Override
            public int compare(User o1, User o2) {
                int age1 = o1.getAge();
                int age2 = o2.getAge();
                if (age1 == age2) {
                    return 0;
                }else {
                    // 從小到大
                    return age1 > age2 ? 1 : -1 ;
                    // 如果需要從大到小，可以將return的值反過來即可
                }
            }
            
        });
        System.out.println("排序后：");
        System.out.println(list);

    }
    
    
    
    
    
        private String name;
        private int 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 User(String name, int age) {
            super();
            this.name = name;
            this.age = age;
        }
        public User() {
            super();
        }
        @Override
        public String toString() {
            return "User [name=" + name + ", age=" + age + "]";
        }
        
        
        
        
        

}