spring aop实现过程之三Spring AOP中Aspect编织的实现

1.上节我们谈到拦截器起作用时，实现代码（ReflectiveMethodInvocation.java）如下：

    public Object proceed() throws Throwable {        //    We start with an index of -1 and increment early.        if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {            return invokeJoinpoint();        }        Object interceptorOrInterceptionAdvice =            this.interceptorsAndDynamicMethodMatchers.get(++this.currentInterceptorIndex);        if (interceptorOrInterceptionAdvice instanceof InterceptorAndDynamicMethodMatcher) {            // Evaluate dynamic method matcher here: static part will already have            // been evaluated and found to match.            InterceptorAndDynamicMethodMatcher dm =                (InterceptorAndDynamicMethodMatcher) interceptorOrInterceptionAdvice;            if (dm.methodMatcher.matches(this.method, this.targetClass, this.arguments)) {                return dm.interceptor.invoke(this);            }            else {                // Dynamic matching failed.                // Skip this interceptor and invoke the next in the chain.                return proceed();            }        }        else {            // It's an interceptor, so we just invoke it: The pointcut will have            // been evaluated statically before this object was constructed.            return ((MethodInterceptor) interceptorOrInterceptionAdvice).invoke(this);        }    }

2.前置Advice MethodBeforeAdviceInterceptor.java

    public Object invoke(MethodInvocation mi) throws Throwable {        this.advice.before(mi.getMethod(), mi.getArguments(), mi.getThis() );        return mi.proceed();    }

3.后置Advice AfterReturningAdviceInterceptor.java

    public Object invoke(MethodInvocation mi) throws Throwable {        Object retVal = mi.proceed();        this.advice.afterReturning(retVal, mi.getMethod(), mi.getArguments(), mi.getThis());        return retVal;    }