The spring-aop module provides an AOP Alliance-compliant aspect-oriented programming implementation allowing you to define, for example, method interceptors and pointcuts to cleanly decouple code that implements functionality that should be separated. Using source-level metadata functionality, you can also incorporate behavioral information into your code, in a manner similar to that of .NET attributes.

The separate spring-aspects module provides integration with AspectJ.

The spring-instrument module provides class instrumentation support and classloader implementations to be used in certain application servers. The spring-instrument-tomcat module contains Spring’s instrumentation agent for Tomcat.

spring-aop模块提供了一个符合AOP Alliance-compliant的面向方面的编程实现，允许你定义例如方法拦截器和切入点来干净地解耦实现应该分离的功能的代码。 使用源代码级元数据功能，你还可以以类似于.NET属性的方式将行为信息合并到代码中。

单独的spring-aspects模块提供与AspectJ的集成。

spring-instrument-tomcat 模块提供类仪器支持和类加载器实现以在某些应用服务器中使用。 spring-instrument-tomcat模块包含Spring的Tomcat的工具代理。