如何从默认包导入类 [英] How to import a class from default package

问题描述

可能的重复:如何在默认包?

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我正在使用 Eclipse 3.5，并且我创建了一个项目，其中包含一些包结构和默认包.我在默认包中有一个类 - Calculations.java，我想在任何包中使用该类(例如在 com.company.calc 中).当我尝试使用默认包中的类时，它给了我一个编译器错误.它无法识别默认包中的类.问题出在哪里?

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I am using Eclipse 3.5 and I have created a project with some package structure along with the default package. I have one class in default package - Calculations.java and I want to make the use of that class in any of the package (for instance in com.company.calc). When I try to make the use of the class which is in the default package, it's giving me a compiler error. It's not able to recognise the class in default package. Where is the problem?

Calculations.java - 源代码

Calculations.java - source code

public class Calculations {
    native public int Calculate(int contextId);
    native public double GetProgress(int contextId);
    static  {
        System.loadLibrary("Calc");
    }
}

我不能将我的课程放在任何其他包中.这个类有一些在 Delphi 中实现的本地方法.如果我将该类放在任何文件夹中，我将不得不对我想避免的那个 DLL 进行更改(真的 - 我不能).这就是为什么我把我的类放在默认包中.

I can't put my class in any other package. This class has some native methods which are implemented in Delphi. If I put that class in any of the folders, I will have to make changes to that DLL which I want to avoid (really - I can not). That's why I put my class in the default package.

推荐答案

来自 Java 语言规范:

从未命名的包中导入类型是编译时错误.

It is a compile time error to import a type from the unnamed package.

您必须通过反射或其他一些间接方法访问该类.

You'll have to access the class via reflection or some other indirect method.

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