Simple factory with class registration using reflection

For this method, we are going to use a map to keep the product IDs along with their corresponding classes:

private Map<String, Class> registeredProducts = new HashMap<String,Class>();

Then, we add a method to register new vehicles:

public void registerVehicle(String vehicleId, Class vehicleClass)
{
  registeredProducts.put(vehicleId, vehicleClass);
}

The create method becomes the following:

public Vehicle createVehicle(String type) throws InstantiationException, IllegalAccessException
{
  Class productClass = registeredProducts.get(type);
  return (Vehicle)productClass.newInstance();
}

In certain situations, working with reflection is either impossible or discouraged. Reflection requires a runtime permission that may not be present in certain environments. If performance is an issue, reflection may slow the program and so should be avoided.