Java泛型在參數類型上檢核的問題

el java 泛型

weberhwang 2019-02-14 21:03:59 ‧ 1146 瀏覽

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大家好
下面這個泛型的例子，為何
Car<Number,String,Integer> car1 = new Car<Number,String,Integer>(1,2L); 這行
compile會過呢？建構子有明確定義兩個參數要同類別，但我傳入不同類別的參數，卻仍會過？

public class Car<T,E,F>{
  private T key; 
  private T oil;
  private E type;
  private F kind;

  public Car(){ }
  public Car(T Key, T oil){
    this.key = key;
    this.oil = oil;
  }
  public void printOil(){
    System.out.println("這部車要加" + oil.getClass() + "種類的油");	 
  }
  public static void main(String[] args){
    Car<Number,String,Integer> car1 = new Car<Number,String,Integer>(1,2L); 
      car1.printOil();
  }
}