Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Ran into some questionable behavior using lists of parameterized Class objects:
ArrayList<Class<String>> classList = new ArrayList<Class<String>>();
classList.add(Integer.class); //compile error
Class intClass = Integer.class;
classList.add(intClass); //legal apparently, as long as intClass is not parameterized
Found the same behavior for LinkedList, haven’t tried other collections. Is it like this for a reason? Or have I stumbled on something?
That is legal only as a concession to backward compatibility so that code written before Java 5 can be compiled in 5 or later without going through and adding generics. Using a raw type for another reason is generally considered a programming error or at least poor style/laziness.
By willfully declaring a Raw Type you’re abandoning the compiler’s ability to help you with type safety, so you get a warning and it’s back on you to make sure things are safe at run time.