派生类如何调用基类的私有方法？

public class PrivateOverride {  

    private void f() {  
        System.out.println("private f()");  
    }
}  

public class Derived extends PrivateOverride {  

    public void f() {                         //this method is never run.
        System.out.println("public f()");     
    }  
}  

public static void main(String[] args) {

    // instantiate Derived and assign it to 
    // object po of type PrivateOverride.
    PrivateOverride po = new Derived();  

    // invoke method f of object po.  It
    // chooses to run the private method of PrivateOveride
    // instead of Derived
    po.f();                         
  }  
}  

所以，这段代码的输出是private f()。现在，我的脑海中出现了一个问题：如何才能po这是一个对象Derived类调用私有方法私有覆盖它的基类是哪个？

因为你定义了 main 方法PrivateOverride班级。如果将 main 方法放在派生类中，它将无法编译，因为.f()那里将不可见。

po.f() 调用PrivateOverride类不是多态性，因为f() in PrivateOverride类是private, so f() in Derived类未被覆盖。