集合元素比对时的输出不合预料

比对应该是从第一个开始的，为什么结果没有按顺序输出？该怎么改？


package thirdJava;


import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;

class student{
    
    private String num ;
    private String name ;
    private int cl  ;
    public student(String num, String name, int cl) {
        super();
        this.num = num;
        this.name = name;
        this.cl = cl;
    }
    public String getNum() {
        return num;
    }
    public String getName() {
        return name;
    }
    public int getCl() {
        return cl;
    }
    
    
}
public class oj2142 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner sc = new Scanner(System.in) ;
        int n = sc.nextInt() ;
        Map<student,String> map = new HashMap<student,String>() ;
        for(int i=0; i<n; i++){
            
            map.put(new student(sc.next(),sc.next(),sc.nextInt()), sc.next()) ;
            
        }
        
        Set<Entry<student,String>>  en = map.entrySet() ; 
        int m = sc.nextInt() ;
        Map<String,String> map2 = new HashMap<String,String>() ;
        
        for(int j=0; j<m; j++){
            
            map2.put(sc.next(), sc.next()) ;
        }
        
        Set<Entry<String,String>> sets = map2.entrySet() ;
        for(Entry<student,String> x : en){
            
            
            for(Entry<String,String> y : sets){
                

                if(x.getValue().equals(y.getKey())){
                    
                    System.out.println(x.getKey().getNum() + " " + y.getValue());
                }
            }
        }
        
        
        
    }

}

img

map是无序的