Java generics, how do you force a superclass to extend to two parameters of a method of the same type?

Suppose I have a class hierarchy as follows:

class Vehicle;
class Car extends Vehicle;
class Plane extends Vehicle;

I have a function to compare two objects

public <T extends Vehicle> generateDiff(T original,T copy)

During compilation, the above method ensures that the two objects are vehicles, but it cannot ensure that the types of the two objects are the same

generateDiff(new Car(),new Car()); //OK
generateDiff(new Plane(),new Plane()); //OK
generateDiff(new Car(),new Plane()); //WRONG

Can I use generics at compile time?

P. S: at present, if the classes of two objects are different, I have implemented it, and an exception will be thrown But I'm not satisfied with it

Thank you in advance

Solution

Yes, you can!

The parameter of type T is inferred, but you can specify the type:

MyClass.<Car>generateDiff(new Car(),new Plane()); // generates a compile error

Xinxin 200 Xinxin 200 200 200 200:200 200: CE X - 200 200 200:200 200 200:20045 200 x-

generateDiff(new Car(),new Plane()); // type is inferred as Vehicle
MyClass.<Vehicle>generateDiff(new Car(),new Plane());

The above code assumes that generatediff () is a static method New flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag new flag