java - Java 是否会阻止重写静态方法？

Question

我不明白为什么当我尝试编译此代码时编译器显示错误:

class A
{
    public static void f()
    {
        System.out.println("A.f()");
    }
}

class B extends A
{
    public static int f()
    {
        System.out.println("B.f()");
        return 0;
    }
}

A类和B类中的两个方法之间的区别是返回类型， 我读到 Java 阻止重写静态方法。 所以我期望编译器不应该显示任何错误，因为最初没有任何覆盖!!

Answer 1

Java Language Specification有以下规则:

8.4.8.3. Requirements in Overriding and Hiding

If a method declaration d1 with return type R1 overrides or hides the declaration of another method d2 with return type R2, then d1 must be return-type-substitutable (§8.4.5) for d2, or a compile-time error occurs.

This rule allows for covariant return types - refining the return type of a method when overriding it.

因此，即使该方法隐藏了父类(super class)并且不重写它，返回类型仍然必须兼容。