api - API 设计：全局变量与传递对象

Question

我正在维护旧版 SDK。SDK 对于不同的平台会有不同的表现。它使用静态变量，并且需要在任何 API 调用之前创建静态变量，如下所示：

静态全局变量（旧代码）的示例：

SDKContext.init();
VideoManager manager = new VideoManager();
public void VideoManager#search() {
    SDKContext.search();
}

VideoManager 之类的组件无处不在。我的直觉告诉我应该改用局部变量，但不能确定。

局部变量（我的首选方式）：

SDKContext context = new SDKContext();
// Or even using singleton
SDKContext context = SDKContext.getInstance();
VideoManager manager = new VideoManager(context);
public void VideoManager#search() {
     context.search();
}

这两种方法的优缺点是什么？欢迎任何建议/建议。

Answer 1

您可以尝试一些 IoC 容器。我将为您制作“单件”，其中一些甚至具有“自动布线”功能。

Answer 2

I don't think you can call it a FACADE.

Facade is, compared to normal approach, simplified version of API, covering more complex operations underneath. In you case API of VideoManager#search() in both cases - the one you call not-facade, and the one that you claim to be a facade - is exactly the same. Moreover, method body is nearly the same too. Replacing global variable with object does not have anything common with being a facade, it's just a decision you can make during the implementation.

Global variable (or singleton) can simplify your code (in such case, where you need to pass it around to a lot of places, it can be worth of give it a try), at cost of harder testing (mocking) it - the decision is up to you.

Answer 3

静态使单元测试变得困难。

方法2要好得多。它对 IoC 友好且易于测试。