springAOP——代理对象的产生及方法调用

代理对象的创建

getObject--》

void org.springframework.aop.framework.ProxyFactoryBean.initializeAdvisorChain() throws AopConfigException, BeansException

初始化拦截器链路--》

addAdvisorOnChainCreation(advice, name);找到advisor并添加--》

this.advisors.add(pos, advisor);设置advisors集合。--》

然后创建代理对象，可以用JDK动态代理或者CGLIB字节码加强。

ProxyFactoryBean继承了AdvisedSupport，在创建AopProxy（例如org.springframework.aop.framework.JdkDynamicAopProxy）实例的时候会把自己传递过去，也就是AopProxy持有一个AdvisedSupport，也就只有了advisors——》简单来说，aop代理对象知道自己上有哪些拦截器（通知器），在invoke的时候来解析。--》

invoke 以JDK动态代理为例

 Object org.springframework.aop.framework.JdkDynamicAopProxy.invoke(Object proxy, Method method, Object[] args)

//目标对象

target = targetSource.getTarget();

// Get the interception chain for this method.

List<Object> chain = this.advised.getInterceptorsAndDynamicInterceptionAdvice(method, targetClass);

获取拦截器链路

然后构造一个MethodInvocation——invocation = new ReflectiveMethodInvocation(proxy, target, method, args, targetClass, chain);递归调用

拦截器链路的获取：List<Object> org.springframework.aop.framework.AdvisedSupport.getInterceptorsAndDynamicInterceptionAdvice(Method method, Class targetClass)回归到了AdvisedSupport

cached = this.advisorChainFactory.getInterceptorsAndDynamicInterceptionAdvice(

     this, method, targetClass);--》

List<Object> org.springframework.aop.framework.DefaultAdvisorChainFactory.getInterceptorsAndDynamicInterceptionAdvice(Advised config, Method method, Class targetClass)

 boolean hasIntroductions = hasMatchingIntroductions(config, targetClass);//检查是否有IntroductionAdvisor配置

 for (Advisor advisor : config.getAdvisors()) {开始处理config其实就是我们前面提到的那个AdvisedSupport，它代表了配置，持有所有通知器

 。。。

 MethodInterceptor[] interceptors = registry.getInterceptors(advisor);//Advisor中提取MethodInterceptor，这个很重要，不管是通知还是拦截器统统转换为MethodInterceptor

 --》

  MethodInterceptor[] org.springframework.aop.framework.adapter.DefaultAdvisorAdapterRegistry.getInterceptors(Advisor advisor) throws UnknownAdviceTypeException

 这是一个适配器，可以处理本来就是MethodInterceptor的，也可以处理各种Advice（如MethodBeforeAdvice）：

   //如果是MethodInterceptor

  if (advice instanceof MethodInterceptor) {

   interceptors.add((MethodInterceptor) advice);

  }

  //如果是其他通知器

  for (AdvisorAdapter adapter : this.adapters) {//各种适配器将Advice转换为MethodInterceptor

   if (adapter.supportsAdvice(advice)) {

    interceptors.add(adapter.getInterceptor(advisor));

   }

  }

  adapter有三种：MethodBeforeAdviceAdapter、AfterReturningAdviceAdapter、ThrowsAdviceAdapter他们都实现了这样的接口adapter.getInterceptor(advisor)，如

 class MethodBeforeAdviceAdapter implements AdvisorAdapter, Serializable {

 public boolean supportsAdvice(Advice advice) {

  return (advice instanceof MethodBeforeAdvice);

 }

 //将MethodBeforeAdvice提取出来转换成MethodBeforeAdviceInterceptor（实现了MethodInterceptor接口），那么在构造MethodInvocation一次调用各拦截器invoke方法的时候，就变成了前置、后置、环绕处理。

 public MethodInterceptor getInterceptor(Advisor advisor) {

  MethodBeforeAdvice advice = (MethodBeforeAdvice) advisor.getAdvice();

  return new MethodBeforeAdviceInterceptor(advice);

 }

}