Declaring classes that implement interfaces
Now, we will declare a concrete class that specifies that it implements the DrawableInComic interface in its declaration in JShell. Instead of specifying a superclass, the class declaration includes the name of the previously declared DrawableInComic interface after the class name (SiperDog) and the implements keyword. We can read the class declaration as "the SpiderDog class implements the DrawableInComic interface." The code file for the sample is included in the java_9_oop_chapter_08_01 folder, in the example08_02.java file.
public class SpiderDog implements DrawableInComic {
}The Java compiler will generate an error because the SpiderDog class is declared as a concrete class and doesn't override all the abstract methods declared in the DrawableInComic interface. JShell displays us the following error, indicating that the first method declaration in the interface isn't overridden:
jshell> public class SpiderDog implements DrawableInComic ...