有几种解决方案：

1. 您可以添加公共构造函数并从测试中调用它。虽然它没有意义，但它也没有太大的伤害。

1. You can add a public constructor and call it from a test. While it doesn't make sense, it also doesn't hurt (much).

创建一个虚拟静态实例（你可以在这里调用私有构造函数） 。丑陋，但你可以给该字段一个名称来传达你的意图（ JUST_TO_SILENCE_COBERTURA 是个好名字。）

Create a dummy static instance (you can call the private constructor here). Ugly but you can give the field a name to communicate your intent (JUST_TO_SILENCE_COBERTURA is a good name).

您可以让测试扩展辅助类。那将本质上调用默认构造函数，但你的助手类不能再是 final 。

You can let your test extend the helper class. That will intrinsically call the default constructor but your helper class can't be final anymore.

我建议最后一种方法，特别是因为该课程不能 final 了。如果代码的使用者想要添加另一个辅助方法，他们现在可以扩展现有的类并接收一个句柄来获取所有辅助方法。这会创建一个辅助方法的耦合，它传达意图（这些属于一起） - 如果帮助程序类是 final

I suggest the last approach especially because the class can't be final anymore. If a consumer of your code wants to add another helper method, they can now extend the existing class and receive one handle to get to all helper methods. This creates a coupling of the helper methods which communicates the intent (these belong together) - which is impossible if the helper class is final

如果你想阻止用户意外地实例化帮助程序类，请将其设为 abstract ，而不是使用隐藏的构造函数。

If you want to prevent users to accidentally instantiate the helper class, make it abstract instead of using a hidden constructor.