java集合排序问题求排序部分代码

import java.util.*;

public class Student {

    public String name;
    public int score;    
     public static  void main (String[] args) {
        System.out.println("*****录入学员信息，当录入学员的姓名分数为0时结束*****");
        Scanner input = new Scanner(System.in);
        ArrayList<Student> arraylist = new ArrayList<Student>();
        //输入学员信息



       while(true){ 
             Student student = new Student();
             System.out.println("请输入学员姓名：");
                   student.name = input.next();
                                        arraylist.add(student);
             }
             System.out.println("请输入学员分数：");
             student.score = input.nextInt();

          if(student.score==0){
                   System.out.println("结束录入！");
                   break;
                   }
                   }


        //按照成绩排序













         //输出学员信息
         System.out.println("学员的信息如下：");
         System.out.println("姓名\t分数\t");
         Iterator<Student> iterator = arraylist.iterator();
         while(iterator.hasNext()){
                Student a = iterator.next();
                System.out.println(a.name+"\t"+a.score+"\t");
      }
      }

}