製作一個HashMap，其鍵值爲HashSets

Question

嘗試使用字符串鍵和HashSets的值生成Hash Map。我想哈希集是所有整數

Set<String> numbersSet = new HashSet<Integer>(); 

// won't work: 
HashMap<String, numberSet> database = new HashMap<String, numberSet>();//error - "(or [ expected" 

//Also won't work. If it did, how can even I add to the set inside this hashMap? 
HashMap<String, HashSet<Integer>> database = new HashMap<String, HashSet<Integer>>(); //error-incompatible types 

Answer 1

HashMap<String, HashSet<Integer>> database = new HashMap<String, HashSet<Integer>>(); 

爲我工作。

順便說一句，如果要使用JDK 1.7可以使用：

HashMap<String, HashSet<Integer>> mymap = new HashMap<>();