Is it possible to solve the “A generic array of T is created for a varargs parameter” compiler warning?

Question

This is a simplified version of the code in question, one generic class uses another class with generic type parameters and needs to pass one of the generic types to a metho

Answer 1

If you're after a fluent-type interface, you could try the builder pattern. Not as concise as varargs but it is type safe.

A static generically-typed method can eliminate some of the boilerplate when using the builder, while retaining the type safety.

The builder

public class ArgBuilder implements Iterable {

    private final List args = new ArrayList();

    public ArgBuilder and(T arg) {
        args.add(arg);
        return this;
    }

    @Override
    public Iterator iterator() {
        return args.iterator();
    }

    public static  ArgBuilder with(T firstArgument) {
        return new ArgBuilder().and(firstArgument);
    }
}

Using it

import static com.example.ArgBuilder.*;

public class VarargsTest {

    public static void main(String[] args) {
        doSomething(new ArgBuilder().and("foo").and("bar").and("baz"));
        // or
        doSomething(with("foo").and("bar").and("baz"));
    }

    static void doSomething(Iterable args) {
        for (String arg : args) {
            System.out.println(arg);
        }
    }
}