Java Interface Anonymous.

Java Interface and anonymous inner class

• Anonymous inner class is a class that has no name and the implementation is combined with instantiation of an object.
• Can also be created through extending a class, but in this case as implementing an interface.
  Using an interface implementation example:

  interface Reputation {
    // default method
    default public String getInfo() {
      return "Bad for business";
    }
  }
  class Car {
    private String initialReputation=null;
    private List<String> reputations= new ArrayList<String>();
    public Car() {
    }
    public Car(String initialReputation) {
      this.initialReputation=initialReputation;
    }
    public void addReputation(String reputation) {
      reputations.add(reputation);
    }
    Reputation obj = new Reputation() {   // Anonymous inner class
      @Override       // Overriding interface default method
      public String getInfo() {
        String returns ="";
        if (initialReputation==null){
          returns = Reputation.super.getInfo();
        }else {
         returns = initialReputation; 
        }
        for (String ret : reputations) {
          returns +="\n"+ret;
        }
        return returns;
      }
    };
  }
  public class CarReputationApp {
    public static void main(String[] args) {
      Car myCar1 = new Car("High performance"); // instantiated object of class car
      myCar1.addReputation("New car");
      myCar1.addReputation("Comfortable to drive");
      myCar1.addReputation("Low price");
      System.out.println("Car 1 reputations:\n" + myCar1.obj.getInfo());
      Car myCar2 = new Car();
      System.out.println("\nCar 2 reputations:\n" + myCar2.obj.getInfo());
    }
  }
  

  The result of this is:

  Car 1 reputations:
  High performance
  New car
  Comfortable to drive
  Low price
  
  Car 2 reputations:
  Bad for business

  You can download this example here (needed tools can be found in the right menu on this page).