java - 如何正确使用HashMap？

Question

HashMap savedStuff = new HashMap();
savedStuff.put("symbol", this.symbol); //this is a string
savedStuff.put("index", this.index); //this is an int

给我警告:

HashMap is a raw type. References to generic type HashMap<K,V> should be parameterized  

Answer 1

HashMap<String, Object> savedStuff = new HashMap<String, Object>();

当然，在提取元素时您仍然需要注意使用正确的类型。