cannot select Parameterized Type

Question

I want to create a rest to communicate between server and client.

The constructor given below:

public class RestHelper {
    public Rest         


        

Answer 1

I got the solution.

ResultContainData<Boolean> result = new ResultContainData<>();
RestHelper<User, ResultContainData<Boolean>> helper = new RestHelper<>(url, user, (Class<ResultContainData<Boolean>>)result.getClass());

It's working for me. I am still looking for a better solution.

Answer 2

You can only learn the value of I and R by capturing them in a subclass definition - otherwise they are erased at runtime. Ex:

class MyStringRestHelper extends RestHelper<String, String> {

Then using something like TypeTools you can resolve the values of I and R:

Class<?>[] typeArgs = TypeResolver.resolveRawArguments(RestHelper.class, MyStringRestHelper.class);
Class<?> i = typeArgs[0];
Class<?> r = typeArgs[1];
assert i == r == String.class;