how to handle Unchecked cast warning in java code

Question

I am unable to handle Unchecked cast warning in my java code :

Set<String> set1=new HashSet<String>();
            Object obj="apple";
            set1=(Set<String>)obj;  // warning Type safety: Unchecked cast from Object to Set<String>

in 3rd line I am getting an warning. How can I remove this. Please suggest. I don't want to use suppress warning code.

Answer 1

Assuming you are trying to add elements to a Set of Strings your code should be:

Set<String> set1 = new HashSet<String>();
String obj = "apple";
set1.add(obj); 

Answer 2

You can't get rid of the warning without either suppressing it, or completely changing the meaning of the code as written .

And even if you do suppress the warning, you will still get an exception at runtime because you are casting a String to a Set . That can never work.

It is difficult suggest a correction because you don't say what you are actually trying to do here. (I can think of three possibilities ...)

Answer 3

String obj ="apple";
set1.add(obj);

also see How do I address unchecked cast warnings?