replace conditional with polymorphism

Este metodo de refactorizacion ha ido cambiando , he empezado a trabajar con el ejemplo que se puede ver en Refactorización: Reemplazar un condicional por polimorfismo
y he acabado implementando un factory patter al estilo de la web
el codigo inicial era , completado para que funcione.

double final MAX_VEHICLE_SPEED = 18;
double final TRUKC_LOAD_FACTOR = 28;
double final BUS_SAFETY_FACTOR = 44;
double loadFactor;
double safetyFactor;

double getSpeed(){

_type= "CAR";
_load = 12;
_risk = 3;
setLoadFactor (TRUCK_LOAD_FACTOR);
setSafetyFactor (BUS_SAFETY_FACTOR);

switch (_type) {
case CAR:
return getMaxSpeed();
case TRUCK:
return getMaxSpeed() - getLoadFactor()* _load;
case BUS:
return getMaxSpeed() - getSafetyFactor()*_risk;
}
double getMaxSpeed()
{
return MAX_VEHICLE_SPEED;
}
private setLoadFactor(Double factor)
{
loadFactor = 0;
if (factor) loadFactor = factor;
}
double getLoadFactor()
{
return loadFactor;
}
private setSafetyFactor(Double factor)
{
safetyFactor = 0;
if (factor) safetyFactor = factor;
}
double getSafetyFactor()
{
return safetyFactor;
}

esto pasa de la forma que se puede observar en el archivo de MoonEdit

Class Cliente
{
private Integer _load;
private Integer _risk;
privat String _type;

double getSpeed()
{
_load = 12;
_risk = 3;
return new VehicleFactory(_type,_load,_risk).getVehicle().getSpeed(); //smell
}
}

Class VehicleFactory
{
final String CAR = "car";
final String BUS = "bus";
final String TRUNCK = "truck";

getVehicle(String type, Integer load , Integer risk)
{
switch (type)
{
case CAR:
return new Car();
case TRUCK:
return new Truck(load);
case BUS:
return new Bus(risk);
}
return new Exception ("Vehiclefactory","no vehicle type");
}
}

Class abstract Vehicle
{
private integer _maxSpeed;

private Integer getMaxSpeed()
{
return _maxSpeed;
}
private setMaxSpeed(Integer speed)
{
_maxSpeed = speed;
}
public abstract Double getSpeed()
}

Class Car extends Vehicle
{
private final Integer CAR_MAX_SPEED = 18;

public Car()
{
setMaxSpeed(CAR_MAX_SPEED);
}

public Double getSpeed()
{
return getMaxSpeed();
}
}

Class Truck
{
private final Integer TRUCK_MAX_SPEED = 18;
private final Integer TRUCK_LOAD_FACTOR = 28;
private Integer _loadFactor;
private Integer _load;

public Truck(Integer load)
{
setMaxSpeed(TRUCK_MAX_SPEED);
setLoadFactor(TRUNK_LOAD_FACTOR);
if (load) _load = load else load = 0;
}
public Integer getLoadFactor()
{
return _loadFactor;
}
private setLoadFactor (Integer loadFactor)
{
_loadFactor = loadFactor;
}
private Double getSpeed()
{
return getMaxSpeed() + getLoadFactor() * _load;
}
}

Class Bus
{
private final Integer BUS_MAX_SPEED = 18;
private final Integer BUS_SAFETY_FACTOR = 44;
private Integer _safetyFactor;
private Integer risk;

public Bus(Integer risk)
{
setMaxSpeed(BUS_MAX_SPEED);
setSafetyFactor (BUS_SAFETY_FACTOR);
if (risk) _risk = risk else _risk =0; ahora luego hago los seters para ponerlo bien.
}
public Integer getsafetyFactor()
{
return _safetyFactor;
}
private setSafetyFactor (Integer safetyFactor)
{
_safetyFactor = safetyFactor;
}
private abstract Double getSafetySpeed()
{
return getMaxSpeed() - getSafetyFactor() * risk;
}
private Double getSpeed()
{
return getSafetySpeed();
}
}