java - 如果重载和覆盖相同的方法，Java中的意外多态行为

Question

我一直在对我的项目进行一些更改，发现一些奇怪的地方，或者更确切地说，我会说 Java 中多态性的意外行为。我在下面给出的 Poc 中复制了相同的行为。
1.CommonInterface.java

package com.general;

public interface CommonInterface {

    public void getViews(String str);

    public void getViews(String str, Long id);

}

2.GenericUtility.java

package com.general;

public class GenericUtility implements  CommonInterface{

    @Override
    public void getViews(String str) {
        System.out.println("This is getViews (single param)from  GenericUtility");
        getViews(str, null);
    }

    @Override
    public void getViews(String str, Long id)  {
        System.out.println("This is getViews (multi-param) from  GenericUtility");
    }

}

3. CustomUtility.java

package com.general;

public class CustomUtility extends GenericUtility {

    @Override
    public void getViews(String str) {
        System.out.println("This is getViews (single param)from  CustomUtility");
        super.getViews(str);
    }

    @Override
    public void getViews(String str, Long id) {
        System.out.println("This is getViews (multi-param) from  CustomUtility");
        super.getViews(str, null);
    }

}

4. Main.java

package com.general;

public class Main {

    public static void main(String[] args) {
        GenericUtility utility = new CustomUtility();
        String str = "Random String";
        utility.getViews(str);
    }
}

运行 Main.java 后，我的预期输出是

This is getViews (single param)from  CustomUtility
This is getViews (single param)from  GenericUtility
This is getViews (multi-param) from  GenericUtility

但我得到的输出是

This is getViews (single param)from  CustomUtility
This is getViews (single param)from  GenericUtility
This is getViews (multi-param) from  CustomUtility
This is getViews (multi-param) from  GenericUtility

我无法理解为什么 com.general.GenericUtility#getViews(java.lang.String)正在调用 com.general.CustomUtility#getViews(java.lang.String, java.lang.Long)这是预期的行为吗？我不知道的是什么？
提前致谢。

Answer 1

Java 使用运行时虚拟分派(dispatch)来调用实例方法(即那些不是静态的)。这仍然适用于对 this 的调用。 ;例如，抽象类可以这样定义抽象方法createResultObject由子类实现并在其doProcessing 中使用该方法方法。
在您的情况下，对象是 CustomUtility ，所以调用this.getViews(String, String)被派往CustomUtility ，然后使用 super内部。