写CDI的人给了你一个大对象工厂;他们为你做的工作比你更好。它是XML配置或注释驱动的，因此您不必将所有内容嵌入到代码中。

The people that wrote CDI gave you one big object factory; they did the work for you, better than you would. It's XML configuration or annotation driven, so you don't have to embed everything in code.

依赖注入引擎（如Spring）比您的工厂做得更多。它将需要多个工厂类和一行代码来复制它们提供的所有内容。

Dependency injection engines, like Spring, do a lot more than your factory. It'll take more than one factory class and one line of code to duplicate all that they offer.

当然，您不必使用它。你总是可以***发明自己的***。您应该 - 如果您的目的是学习如何制作***或消除依赖性。

Of course you don't have to use it. You are always free to invent your own wheel. And you should - if your purpose is to learn how to make wheels or eliminate dependencies.

但如果您只想开发应用程序，***使用其他人提供的工具，这些工具可以为您提供优势。

But if you want to just develop applications, it's better to use the tools that others provide when they give you an advantage.

关于依赖注入的开创性文章由Martin Fowler撰写。我建议阅读它;八年后，它仍然很棒。

The seminal article on dependency injection was written by Martin Fowler. I'd recommend reading it; it's still great, eight years later.

仍然不清楚更多的是什么

"still not clear on what the more is"

以下是一些优点：

1. Looser coupling


2. 更容易测试


3. 更好的分层


4. 基于界面的设计


5. 动态代理（segue to AOP）。

1. Looser coupling
2. Easier testing
3. Better layering
4. Interface-based design
5. Dynamic proxies (segue to AOP).