Storing a new object as the value of a hashmap?

Question

I am trying to find a way to store a new instance of a class as the value in a Java hashmap. The idea was given to me by a Java instructor in order to create a data storage

Answer 1

Make use of the generics added to java. They help with both compile-time type-checking and they make the casts unnecessary.

  HashMap  mapper = new HashMap();
  //you will be able to retrieve an object and then cast it to your InfoStore
  InforStore isN01 = (InfoStore)mapper.get("N01");

  //this will unfortunately be accepted, even thought it's a bug
  mapper.put("N02", new Integer(0));

  ________________________

  HashMap  mapper = new HashMap();
  //you will be able to retrieve an object and then cast it to your InfoStore
  InforStore isN01 = mapper.get("N01"); //no cast