冒泡排序之如何根据对象一个属性排序

package com.company;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import javax.sound.midi.Soundbank;

public class Main {
    //经典冒泡排序
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int n=scanner.nextInt();
        int[] num=new int[n];
        String[] name=new String[n];
        ArrayList<Student> stu=new ArrayList<Student>();
        for (int i=0;i<num.length;i++){
            name[i]=scanner.next();
            num[i]=scanner.nextInt();
        }
        for (int i=0;i<num.length;i++){
            Student s=new Student(name[i],num[i]);
            stu.add(s);
        }
        Student[] st=new Student[num.length];//类作为数组使用
        stu.toArray(st);
        sort(st,n);
    }
    //从小到大排序
    public static  void sort(Student[] st,int n){
        int i,j,k;
        Student temp;
        for (i=n-1;i>0;i--){
            for (j=0;j<i;j++){
                if (st[j].score>st[j+1].score){
                    temp=st[j];
                    st[j]=st[j+1];
                    st[j+1]=temp;
                }
            }
        }
        for (i=0;i<st.length;i++){
            System.out.print(st[i].name+" ");
        }
    }
    public static class Student{
        String name;
        int score;
        public Student(){}
        public Student(String name,int score){
            this.name=name;
            this.score=score;
        }
    }
}