What is the appropriate way to handle warning: "The expression of type x is boxed into x"

Question

I'm not looking to to turn off or ignore the warning as in The expression of type x is boxed into X?.

I'd like to know what the correct way to handle/avoid this warning is if one was so inclined.

Answer 1

Boxing and unboxing are operations you can do by hand, but they're build into the language to avoid the repetition you will undoubtedly encounter.

Integer obj = Integer.valueOf(5); // instead of Integer obj = 5;
int i = obj.intValue(); // instead of int i = obj;

In my opinion, the appropriate way to handle that warning to turn it off. But if that is not an option, you can do the above.

Answer 2

In my opinion its better to explicitly box-unbox the values as it makes the code more readable. Also there might be subtle differences when we use different approaches to boxing. For eg,

Integer i = new Integer(1);

Integer j = Integer.valueOf(1);

According to javadoc Integer.valueOf() caches objects so i==j will return false.

Also another way to explicitly box a primitive to Integer is

Integer k = (Integer)1; but this actually calls Integer.valueOf().