Question

The compiler throws in a warning if i declare and instantiate a new type safe collection like below

List<String> list = new ArrayList(); // compiler warning
List<String> anotherList = new ArrayList<String>(); //this is normal and ok.

The list object seems to be type safe as I can’t put in any other object other than String in it. So, are there any pitfalls of using such a declaration ?

Answer 1

Because you could have done something like this:

ArrayList foo = new ArrayList();
foo.add(new Integer(5));
List<String> list = foo;  // compiler warning

But this would break the contract that a List<String> should only contain Strings. So that is why you get the warning; in general mixing raw and generic types is bad practice.