Java interfaces are different from classes, ... For example, Cloneable (see Inheritance in Java, Part 2) implies that instances of its implementing class can be shallowly cloned.

Java’s interface language feature confuses many Java newbies. Many mistakenly assume that interfaces only sidestep Java’s failure to support multiple implementation inheritance. In reality ...

Java does enable the option to mark a class as final to eliminate the ability to perform inheritance complete, but that is often too heavy of a hammer to drop. Marking a class as final prevents all ...