是否可以覆盖派生类中的静态方法？ [英] Is it possible to override a static method in derived class?

问题描述

我有一个在基类中定义的静态方法，我想在其子类中覆盖此方法，是否可能？

I have a static method defined in a base class, I want to override this method in its child class, is it possible?

我试过这个但它确实不按我的预期工作。当我创建一个B类实例并调用它的callMe（）方法时，调用A类中的静态foo（）方法。

I tried this but it did not work as I expected. When I created an instance of class B and invoke its callMe() method, the static foo() method in class A is invoked.

public abstract class A {
  public static void foo() {
    System.out.println("I am base class");
  }

  public void callMe() {
    foo();
  }
}

Public class B {
  public static void foo() {
      System.out.println("I am child class");
  }
}

推荐答案

静态方法调用在编译时解析（无动态调度）。

Static method calls are resolved on compile time (no dynamic dispatch).

class main {
    public static void main(String args[]) {
            A a = new B();
            B b = new B();
            a.foo();
            b.foo();
            a.callMe();
            b.callMe();
    }
}
abstract class A {
    public static void foo() {
        System.out.println("I am superclass");
    }

    public void callMe() {
        foo(); //no late binding here; always calls A.foo()
    }
}

class B extends A {
    public static void foo() {
        System.out.println("I am subclass");
    }
}

给出

I am superclass
I am subclass
I am superclass
I am superclass

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