디자인패턴 Delegate pattern 예제

객체 지향 디자인 패턴의 한 종류인 Delegate pattern구현

 

객체를 위임시키기 위한 Delegator와 같은 interface를 상속받는 클래스들이 필요합니다.

 

 - VehiclaManagerService Interface

public interface VehicleManagerService{
	public String myBehicle();
}

 

- VehiclaManagerService 구현클래스

public class CarManagerServiceImpl implements VehicleManagerService{
	@Override
	public String myBehicle() {
		// TODO Auto-generated method stub
		return "Car";
	}
}

public class BusManagerServiceImpl implements VehicleManagerService{
	@Override
	public String myBehicle() {
		// TODO Auto-generated method stub
		return "Bus";
	}
}

public class BoatManagerServiceImpl implements VehicleManagerService{
	@Override
	public String myBehicle() {
		return "Boat";
	}
}

 

- VehicleEnum

public enum VehicleEnum {
	_BUS,
	_CAR,
	_BOAT
}

- DelegatorVehicleManagerDelegator : delegate역할을 수행하는 delegator

public class VehicleManagerDelegator {
	private VehicleManagerService vehicleManager;
	
	public VehicleManagerDelegator(VehicleEnum behicle) {
		switch(behicle) {
		case _BOAT:
			vehicleManager = new BoatManagerServiceImpl();
			break;
		case _BUS:
			vehicleManager = new BusManagerServiceImpl();
			break;
		case _CAR:
			vehicleManager = new CarManagerServiceImpl();
			break;
		default:
			break;
		}
	}
	public VehicleManagerService getVehicleManager() {
		return vehicleManager;
	}
	public void setVehicleManager(VehicleManagerService vehicleManager) {
		this.vehicleManager = vehicleManager;
	}
}

- main

public class DelegatorMain {
	public static void main(String[] args) {
		VehicleManagerDelegator vehicle;
		
		vehicle = new VehicleManagerDelegator(VehicleEnum._BUS);
		String myVehicle = vehicle.getVehicleManager().myBehicle();
		System.out.println(myVehicle); //Bus
		
		VehicleManagerService vm = new VehicleManagerDelegator(VehicleEnum._BOAT).getVehicleManager();
		myVehicle = vm.myBehicle();
		System.out.println(myVehicle); //Boat
	}
}