Aop的几个术语

从Spring文档来的，清楚定义了几个aop的术语,因为aop这些术语并不直观，所以专门列出来备查。
• Aspect: A modularization of a concern for which the implementation might otherwise cut across multiple
objects. Transaction management is a good example of a crosscutting concern in J2EE applications. Aspects
are implemented using Spring as Advisors or interceptors.
• Joinpoint: Point during the execution of a program, such as a method invocation or a particular exception
being thrown.
• Advice: Action taken by the AOP framework at a particular joinpoint. Different types of advice include
"around," "before" and "throws" advice. Advice types are discussed below. Many AOP frameworks,
including Spring, model an advice as an interceptor, maintaining a chain of interceptors "around" the
joinpoint.
• Pointcut: A set of joinpoints specifying when an advice should fire. An AOP framework must allow
developers to specify pointcuts: for example, using regular expressions.

• Introduction: Adding methods or fields to an advised class. Spring allows you to introduce new interfaces
to any advised object. For example, you could use an introduction to make any object implement an
IsModified interface, to simplify caching.
• Target object: Object containing the joinpoint. Also referred to as advised or proxied object.
• AOP proxy: Object created by the AOP framework, including advice. In Spring, an AOP proxy will be a
JDK dynamic proxy or a CGLIB proxy.
• Weaving: Assembling aspects to create an advised object. This can be done at compile time (using the
AspectJ compiler, for example), or at runtime. Spring, like other pure Java AOP frameworks, performs
weaving at runtime.