Java class with concrete type as parameter

Question

Is there any point in declaring a class with \"concrete\" types as generics?

If yes, what\'s the use for it?

If no, any specific reason why the compiler is

Answer 1

In the class definition the parameter you called Integer could be also just be T without changing the sense.

AFIK you can omit the generic just in Java 7 where the compiler adds this automatically it is anyway not stored at runtime. So you must define the generic in a lefthand definition, the only exception of this is using the question mark which is used as a wildcard.

// here is the generic missing the compiler cannot guess it:
SomeClass<> iSome = new SomeClass<>();
// here does the compiler know that you want a Double
SomeClass<Double> jSome = new SomeClass<>();
// this will also work
SomeClass<?> kSome = new SomeClass<Boolean>();

Answer 2

It's not what you think. You're creating a generic type parameter called Integer which shadows java.lang.Integer.