Writing concurrent code is hard to begin with; the language should not make it any harder.

开始编写并发代码是一件困难的事情，语言不应当增加它的难度。

At each step, we've found techniques better than the previous to let us decouple code from hard dependencies.

在每一步上，我们都会发现比以前更好的技术可以让我们把代码从硬依赖中解耦出来。

Now that you've seen all the hard ways to code EJBs, the next section will show you how to turbo-charge your productivity and optimize your application.

通过上述内容您看到了对EJB进行编码的困难之处，下一部分将显示如何提高工作效率和优化应用程序。

I believe that if you can avoid having to give up secondary design goals to meet your primary goals, you can avoid writing code that becomes hard to use or hard to change.

我相信，如果在实现主要目标的同时能够不放弃次要目标，那么就可以避免编写难以使用或修改的代码。

At best this caused hard to maintain code and at worst brittle code that fails when new types in the enterprise extend existing types.

即使最好的情况下这也会带来代码维护的困难，而最坏的情况当企业扩展现有类型而引入新类型时，脆弱的代码就会失效。