Passing to the constructor of any object?

Question

Java

A question. How to write constructor arguments so that any object that implements the desired interface is accepted?
in theory it should be something like this

public MyClass(<? extends MyInterface> obj){
...
}

But that doesn't work. How to implement it correctly in java?

Answer 1

public MyClass(MyInterface obj){
...
}

Answer 2

It is possible like this:

public <T extends SomeInterface> MyClass(T object) {
}

Answer 3

This is called generics.

class MyClass<T extends MyInterface>{
private T val;
public MyClass(T obj){
val= obj;
...
}
}

In your situation, you can do something like this:

public MyClass(MyInterface obj){
...
}