Java Interface

메소드 시그니처와 상수만 정의
설계도(Specification)와 같은 역할
다양한 방법으로 구현(implementation) 가능
공통의 타입 역할

example

Car.java

public interface Car {
    public int getSpeed();
    public boolean accelerate();
}

Avante.java

public class Avante implements Car {
    int speed;

    @Override
    public int getSpeed() {
        return speed;
    }

    @Override
    public boolean accelerate() {
        speed += 10;
        return false;
    }

}

Matiz.java

public class Matiz implements Car {
    int speed;

    @Override
    public int getSpeed() {
        return speed;
    }

    @Override
    public boolean accelerate() {
        speed += 20;
        return false;
    }

}

Drive.java

public class Drive {
    public static void main(String[] args) {
        Car avante = new Avante();
        Car matiz = new Matiz();

        drive(avante, "Avante");
        drive(matiz, "Matiz");
    }

    private static void drive(Car car, String name) {
        System.out.println(name);
        for (int i = 0; i < 10; i++) {
            car.accelerate();
            System.out.println(i + ":" + car.getSpeed());
        }
    }
}