当把商品加入购物车是报错了

java.lang.Error: Unresolved compilation problems:
The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files
Map.Entry cannot be resolved to a type
The method entrySet() from the type HashMap<Items,Integer> refers to the missing type Map$Entry
Map.Entry cannot be resolved to a type
是不是我缺Map包 ，需要下载导入吗？