使用hashmap列表访问嵌套循环中的对象

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class NestedLoopHashMapExample {
    public static void main(String[] args) {
        // 创建一个HashMap列表
        List<Map<String, Object>> nestedList = new ArrayList<>();

        // 创建第一层级的HashMap对象
        Map<String, Object> firstLevelMap1 = new HashMap<>();
        firstLevelMap1.put("name", "John");
        firstLevelMap1.put("age", 25);

        // 创建第二层级的HashMap对象
        Map<String, Object> secondLevelMap1 = new HashMap<>();
        secondLevelMap1.put("subject", "Math");
        secondLevelMap1.put("score", 90);

        // 将第二层级的HashMap对象添加到第一层级的HashMap对象中
        firstLevelMap1.put("course", secondLevelMap1);

        // 将第一层级的HashMap对象添加到HashMap列表中
        nestedList.add(firstLevelMap1);

        // 创建第一层级的HashMap对象
        Map<String, Object> firstLevelMap2 = new HashMap<>();
        firstLevelMap2.put("name", "Alice");
        firstLevelMap2.put("age", 30);

        // 创建第二层级的HashMap对象
        Map<String, Object> secondLevelMap2 = new HashMap<>();
        secondLevelMap2.put("subject", "English");
        secondLevelMap2.put("score", 85);

        // 将第二层级的HashMap对象添加到第一层级的HashMap对象中
        firstLevelMap2.put("course", secondLevelMap2);

        // 将第一层级的HashMap对象添加到HashMap列表中
        nestedList.add(firstLevelMap2);

        // 访问嵌套循环中的对象
        for (Map<String, Object> firstLevelMap : nestedList) {
            String name = (String) firstLevelMap.get("name");
            int age = (int) firstLevelMap.get("age");
            Map<String, Object> secondLevelMap = (Map<String, Object>) firstLevelMap.get("course");
            String subject = (String) secondLevelMap.get("subject");
            int score = (int) secondLevelMap.get("score");

            System.out.println("Name: " + name);
            System.out.println("Age: " + age);
            System.out.println("Subject: " + subject);
            System.out.println("Score: " + score);
            System.out.println();
        }
    }
}