Question

I have a method that usually takes an item from a list and has a signature of:

myMethod(T item)

I want to use this method but I know what I am sending the method.

SpecificItem myItem = new SpecificItem();

myMethod((T) myItem);

This doesn’t sit well with me. Is this a sign of bad code?

Answer 1

myMethod is defined in a generic class, somewhat like:

public class MyClass<T> {
   T myItem;

   public void myMethod(T item) {
      // do Something with item
   }

   public T myOtherMethod() {
      myMethod(myItem);   // casting is not necessary
      return myItem;
   }

}

If you instantiate this class, you exchange the variable type T with a real one:

MyClass<SpecificItem > concreteClass = new MyClass<SpecificItem >();

And if you call myMethod on this instance, you have to provide a SpecificItem, because SpecificItem is the generic type for this instance.

^{(I’m not sure it my post answers your question, please comment so I can improve it)}