XML turned out to be a very powerful syntax to express complex and deeply hierarchical configuration files, but it also came with a few shortcomings
that made Java development harder than it could have been. For example, the Java EE XML configuration files need to be tightly synchronized with the Java classes they extend, and as such, they find themselves having
to invent a syntax that lets them pinpoint very specific Java elements (e.g., a method inside a class inside a package) in order to attach metadata to these
elements.

XML在表达复杂性和深度层次化的配置文件方面，已被证实是一种非常有力的语法，但它也有一些缺点，让Java开发变得没有必要地困难。例如，Java EE XML配置文件需要与它们相关的Java类严格同步，也正因为如此，人们发现必须发明一种语法，以便能盯住非常具体的Java元素（如一个包中的一个类中的一个方法），为这些元素提供元数据。