Java 集合框架-------集合嵌套

public class MapTest {
            public static void main(String[] args) {
                //使用map集合存储
                Map> data = new HashMap<>();
                List selects = new ArrayList<>();
                Collections.addAll(selects,"a","c","d");
                data.put("子辰",selects);

                List selects2 = new ArrayList<>();
                Collections.addAll(selects2,"a");
                data.put("代梓",selects2);

                List selects3 = new ArrayList<>();
                Collections.addAll(selects3,"a","b");
                data.put("辰",selects3);

         List selects4 = new ArrayList<>();
        Collections.addAll(selects4,"d");
        data.put("子",selects4);


        System.out.println(data);
        //统计每个选择的人数
        Map maps = new HashMap<>();
        //提取所有人选择的信息
        Collection> values = data.values();
        System.out.println(values);


      for (List value : values){
          for (String s : value){
              //有没有包含这个信息
              if(maps.containsKey(s)){
                  maps.put(s,maps.get(s) + 1);
              }else{
                  maps.put(s,1);
              }
          }
      }
        System.out.println(maps);


    }
}