java - 可变参数重载

Question

任何人都可以解释为什么这段代码会抛出一个不明确的重载错误，整数方法肯定更具体和适用吗？

谢谢，

内德

package object_orientation;
public class Ambiguous {
    //ambiguous error compiler unsure whether boxing is needed or not
    static void overload(Integer... d){
        System.out.println("Integer");
    }

    static void overload(long... d){
        System.out.println("Long");
    }

    public static void main(String a[]){
        int i = 1;
        overload(i);
    }
}

Answer 1

Java 中的这些概念应该会有所帮助，Boxing + Widening is allowed ，但是 not Widening + Boxing .

这些加宽、拳击和 Vararg 规则应该会有所帮助:

1. Primitive Widening > Boxing > Varargs.
2. Widening and Boxing (WB) not allowed.
3. Boxing and Widening (BW) allowed.
4. While overloading, Widening + vararg and Boxing + vararg can only be used in a mutually exclusive manner
5. Widening between wrapper classes not allowed.
6. Widening+varArgs & Boxing+varargs are individually allowed (but not allowed in overloaded version of method).
7. Boxing+Widening is preferred over Boxing+Varargs.

希望这会有所帮助。