本文详细介绍Spring AOP的执行阶段流程。

Cglib代理的代理拦截逻辑在DynamicAdvisedInterceptor中，JDK代理的拦截逻辑在JdkDynamicAopProxy中，本文将从这两个类入手分析Spring AOP的执行阶段流程。

DynamicAdvisedInterceptor

private static class DynamicAdvisedInterceptor implements MethodInterceptor, Serializable {private final AdvisedSupport advised;public DynamicAdvisedInterceptor(AdvisedSupport advised) {this.advised = advised;}@Overridepublic Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {// ...}

intercept方法核心逻辑

Cglib实现的动态代理都是通过这个类的intercept方法进行拦截的：

• 该类在创建时需要传入一个advised对象，这个对象内部封装着所有的Advisor集
• 将advised对象中封装的Advisor集转换成MethodInterceptor链
• 构建一个CglibMethodInvocation并执行拦截器链

代码：

Object oldProxy = null;
boolean setProxyContext = false;
Object target = null;
TargetSource targetSource = this.advised.getTargetSource();
try {if (this.advised.exposeProxy) {// Make invocation available if necessary.oldProxy = AopContext.setCurrentProxy(proxy);setProxyContext = true;}// Get as late as possible to minimize the time we "own" the target, in case it comes from a pool...target = targetSource.getTarget();Class targetClass = (target != null ? target.getClass() : null);// 1. 将Advisor集转换成MethodInterceptor链List