Question

这是我写的代码：

class Car
public Car(String Company,String Model,int Color,String FuelType,double Price,String Engine)
{
boolean  check =  ConstInitCheck(Company,FuelType,Engine,Color);
if((check))
{
this.Company = Company;
this.Model = Model;
this.Color = Color;
this.FuelType = FuelType;
this.Price = Price;
this.Engine = Engine;
}
else System.out.println("Sorry One of the Inputs were wrong! Please Try Again!");
}


public Car(String Company,String Model,int Color,String FuelType,double Price,String Engine,String VIP_Features)
{
boolean  check =  ConstInitCheck(Company,FuelType,Engine,Color);
if((check))
{
this.Company = Company;
this.Model = Model;
this.Color = Color;
this.FuelType = FuelType;
this.Price = Price;
this.Engine = Engine;
if(!VIP_Features.equals(""))this.VIP_Features = VIP_Features;
else this.VIP_Features="None";
}
else System.out.println("Sorry One of the Inputs were wrong! Please Try Again!");
}



private boolean ConstInitCheck(String Company,String FuelType,String Engine,int Color)
{
boolean a = ((Company.toUpperCase().equals("SUZUKI"))||(Company.toUpperCase().equals("TOYOTA"))||(Company.toUpperCase().equals("HYUNDAI"))||
(Company.toUpperCase().equals("VOLKSWAGEN"))||(Company.toUpperCase().equals("FORD"))||(Company.toUpperCase().equals("HONDA"))||(Company.toUpperCase().equals
("CHEVROLET"))||(Company.toUpperCase().equals("SKODA"))||(Company.toUpperCase().equals("FIAT")));
boolean b = ((FuelType.toUpperCase().equals("DIESEL"))||(FuelType.toUpperCase().equals("PETROL"))||(FuelType.toUpperCase().equals("GAS")));
boolean c = ((Engine.toUpperCase().equals("V2"))||(Engine.toUpperCase().equals("V4"))||(Engine.toUpperCase().equals("V6"))||(Engine.toUpperCase().equals("V8"))||

(Engine.toUpperCase().equals("V12")));
boolean d = Color >= 0 & Color <= 255;
boolean initcheck = a && b && c && d;
return initcheck;
}

我在这里读到的一些帖子反对在构造函数中执行方法，因为对象没有完全初始化。但由于我调用的方法只检查输入的实际参数是否正确这是正确的方法吗？如果没有，请告诉我最好的方法。对代码的其他方面的建议或批评也是受欢迎的。

Answer 1

使用工厂方法。将检查移动到方法和构造函数外部。结果是有效对象或根本没有对象。

    class Car{

       //private constructor to prevent creating objects from outside the factory method
       private Car(String Company,String Model,int Color,String FuelType,double Price,String Engine,String VIP_Features)
       {
          this.Company = Company;
          this.Model = Model;
          this.Color = Color;
          this.FuelType = FuelType;
          this.Price = Price;
          this.Engine = Engine;
       }

       //static method that creates the object after functional checks
       public static Car Create(String Company,String Model,int Color,String FuelType,double Price,String Engine,String VIP_Features)
       {
          if(ConstInitCheck(Company,FuelType,Engine,color)){
              return new Car(Company,Model,Color,FuelType,Price,Engine,VIP_Features);
          }
          return null; // or throw exception
       }

       private static boolean ConstInitCheck(String Company,String FuelType,String Engine,int Color){
          ...
       }

    }

用法：

var car = Car.Create(Company,Model,Color,FuelType,Price,Engine,VIP_Features);

检查构造函数中的条件的方法

1 个答案: