避免未經檢查的警告電話

我有以下代碼（一部分）避免未經檢查的警告電話

public class Garage<T extends Vehicle>{ 

    private HashMap< String, T > Cars; 
    private int Max_Cars; 
    private int Count; 

    public Garage(int Max_Cars) 
    { 
     Cars = new HashMap< String, T >(); 
     this.Max_Cars = Max_Cars; 
     Count = 0; 
    } 

    public void add(T Car) throws FullException 
    { 
     if (Count == Max_Cars) 
      throw new FullException(); 

     if (Cars.containsKey(Car.GetCarNumber())) 
      return; 

     Cars.put(Car.GetCarNumber(), Car); 

     Count = Count + 1; 

    } 

......... 
......... 
} 


public class PrivateVehicle extends Vehicle{ 

    private String Owner_Name; 

    public PrivateVehicle(String Car_Number, String Car_Model, 
      int Manufacture_Yaer, String Comment, String Owner_Name) 
    { 
     super(Car_Number, Car_Model, Manufacture_Yaer, Comment); 
     this.Owner_Name = Owner_Name; 
    } 
......... 
......... 
}

這是主要的方法（它的一部分）

public static void main(String[] args) { 

......... 
......... 

    Garage CarsGarage = new Garage(20); 

......... 
......... 

    System.out.print("Owner Name:"); 
    Owner_Name = sc.nextLine(); 

    PrivateVehicle PrivateCar = new PrivateVehicle(Car_Number, Car_Model, 
          Manufacture_Yaer, Comment, Owner_Name); 

    try{ 
     CarsGarage.add(PrivateCar); 
    } 
    catch (FullException e){ 
     continue; 
    } 

......... 
......... 
}

希望的代碼是明確的。車是超級類，它只包含一些關於汽車的更多細節。 Garage類假設將所有汽車保存在散列圖中。有兩種類型的車，PrivateVehicle提到的代碼和LeesingVehicle不是，都是Vehicle的子類。

，當我嘗試編譯使用javac -Xlint它：取消勾選*的.java，我得到以下

Main.java:79: warning: [unchecked] unchecked call to add(T) as a member of the raw type Garage 
         CarsGarage.add(PrivateCar); 
            ^
    where T is a type-variable: 
    T extends Vehicle declared in class Garage 
Main.java:97: warning: [unchecked] unchecked call to add(T) as a member of the raw type Garage 
         CarsGarage.add(LeasedCar); 
            ^
    where T is a type-variable: 
    T extends Vehicle declared in class Garage 
Main.java:117: warning: [unchecked] unchecked conversion 
        CarsList = CarsGarage.getAll(); 
               ^
    required: ArrayList<Vehicle> 
    found: ArrayList 
3 warnings

我怎樣才能避免這種情況的警告？

謝謝。

來源

2013-05-15 user2102697

Garage CarsGarage = new Garage(20);

在這裏，你沒有指定爲Garage類型參數，這實際上是一個泛型類Garage<T extends Vehicle>。你需要：

Garage<Vehicle> CarsGarage = new Garage<Vehicle>(20);

來源

2013-05-15 14:23:51

你的意思是類似的東西車庫 CarsGarage =新的車庫（20）？編譯器如何知道T是什麼？ – user2102697

那麼，更像是車庫 CarsGarage = new Garage （20）。你以前看過泛型嗎？ Sum/Oracle的教程非常棒。 –

工作，非常感謝，對Java和泛型有所瞭解，謝謝。 – user2102697

避免未經檢查的警告電話

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