Why can't I use from the static method of the implemented interface?

Question

As you, specialists, know in Java 8, interfaces can have static methods which have implementations inside themselves.

As I have read in a related tutorial, the classes which implement such interface can use its static methods. But, I have a problem which, here, I show it in a simpler example than what I have

public interface Interface1{
    public static void printName(){
        System.out.println("Interface1");
    }
}

when I implement such interface

public class Class1 implements Interface1{
    public void doSomeThing() {
        printName();
    }
}

I encounter compile error.

The method printName() is undefined for the type Class1

What's the problem?

Answer 1

From the Java Language Specification,

A class C inherits from its direct superclass all concrete methods m (both static and instance) of the superclass for which all of the following are true:

• [...]

A class C inherits from its direct superclass and direct superinterfaces all abstract and default (§9.4) methods m for which all of the following are true:

• [...]

A class does not inherit static methods from its superinterfaces.

So that method is not inherited.

You can statically import the member

import static com.example.Interface1.printName;
...
printName();

or use it with the fully qualified type name

com.example.Interface1.printName();

or import the type to which printName belongs and invoke it with its short name

import static com.example.Interface1;
...
Interface1.printName();