Object cannot be converted to Entry<Character,Integer> for 怎么处理

如图所示, 报错 Object cannot be converted to Entry<Character,Integer>
for(Map.Entry<Character,Integer> entry:map.entrySet())
,这问题出在哪里呢?

HashMap<Character, Integer> map = new HashMap<>();

这样初始化

一般情况下，我们用Map都是用父类来声明：Map<Character, Integer> map = new HashMap<Character, Integer>();