java 中根据类的属性排序

 package edu.del;

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

 class Student implements Comparable<Student>{
     String name;
     int score;

     public Student(String name, int score) {
         this.name = name;
         this.score = score;
     }

     public Student() {

     }

     public String getName() {
         return name;
     }

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

     public int getScore() {
         return score;
     }

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

     @Override
     public String toString() {
         return "Student{" +
                 "name='" + name + '\'' +
                 ", score=" + score +
                 '}';
     }

 //    @Override
 //    public int compareTo(Student o) {
 //        //假如result返回1。Collections.sort(List)方法就是升序;
 //        //假如result返回-1。Collections.sort(List)方法就是降序;
 //        int num=new Integer(o.getScore()).compareTo(this.getScore());//这里面是按照降序排列
 //        //int num=new Integer(this.getScore()).compareTo(this.getScore()); //测试升序
 //        return num;
 //
 //    }
     @Override
     public int compareTo(Student o) {
         //这里是按照名字字符属性排序
         int num =o.getName().compareTo(this.getName());
         //int num=this.getName().compareTo(o.getName());
         return num;
     }
 }

 public class sort_class {
     public static void main(String[] args) {
         Scanner scanner =new Scanner(System.in);
         System.out.println("请输入学生数量：");
         int num =scanner.nextInt();
         Student[] student =new Student[num];
         List<Student> list =new ArrayList<>();

         for (int i = 0; i <num ; i++) {

             list.add(new Student(scanner.next(),scanner.nextInt()));
         }
         Collections.sort(list);

         //输出一下看看

         for (int i = 0; i <num ; i++) {
             System.out.print(list.get(i).getName()+" ");
             System.out.println(list.get(i).score);
         }
     }
 }