Java 11 and 12 – New Features

Implementing interfaces

A data class can implement an interface and its abstract methods, or just inherit its default methods. The following is an example:

interface Organizer {} 
interface Speaker { 
   abstract void conferenceTalk(); 
} 
 
abstract record Emp(String name, int age); 
 
record Manager(String name, int age, String country)  
   extends Emp(name, age)                    // subclass a record
   implements Organizer;                     // implement one interface
 
record Programmer(String name, int age, String programmingLang)  
   extends Emp(name, age)                    // subclass a record
   implements Organizer, Speaker {           // implementing multiple                                              // interfaces
        public void conferenceTalk() {       // implement abstract                                              // method
            //.. code                        // from interface Speaker
        } 
    };

The preceding code defines a tagging ...