package com.suiwei;

import java.text.ParseException;
import java.util.HashMap;
import java.util.Set;

public class B {
    public static void main(String[] args) throws ParseException {
    
        HashMap<String, HashMap<String, Integer>> map = new HashMap<String, HashMap<String,Integer>>();
    
        HashMap<String, Integer> map1 = new HashMap<String, Integer>();
        map1.put("一班张三", 20);
        map1.put("一班李四", 22);
        map.put("一班", map1);
        
        HashMap<String, Integer> map2 = new HashMap<String, Integer>();
        map1.put("二班张三", 200);
        map1.put("二班李四", 222);
        map.put("二班", map2);
        
        Set<String> set = map.keySet();
        for (String string : set) {
            System.out.println(string);
            HashMap<String, Integer> mapneibu = map.get(string);
            Set<String> set2 = mapneibu.keySet();
            for (String string2 : set2) {
                System.out.println(string2+"--"+mapneibu.get(string2));
            }
        }
        
        
        
    }
}

输出结果为：
二班
一班
二班李四--222
一班张三--20
一班李四--22
二班张三--200