先上代碼,比如我使用aspectj風格的注解，定義了一個針對naiveWaiter的切面邏輯

@Aspect
public class TestAspect {
   
    /**
     * 訪問連接點對象
     */
    @Around("execution(* greetTo(..)) && target(com.brianway.learning.spring.aop.aspectj.NaiveWaiter)")
    public void joinPointAccess(ProceedingJoinPoint pjp) throws Throwable {
        System.out.println("------joinPointAccess-------");
        System.out.println("args[0]:" + pjp.getArgs()[0]);
        System.out.println("target:" + pjp.getTarget());
        System.out.println("signature:" + pjp.getSignature());
        System.out.println("this:" + pjp.getThis());

        pjp.proceed();
        System.out.println("-------joinPointAccess-------");
    }

測試類如下

@Test
    public void testJoinPoint() {
        String configPath = "com/brianway/learning/spring/aop/aspectj/beans-advanced.xml";
        ApplicationContext context = new ClassPathXmlApplicationContext(configPath);
        Waiter naiveWaiter = (Waiter) context.getBean("naiveWaiter");
        naiveWaiter.greetTo("Brian");
    }

debug看一下這個naiveWaiter對象到底是什么

462722787.jpg

那么之前的文章bean的生命周期中，這個代理的過程是在哪一步進行的呢
createBeanInstance
populateBean
initlizeBean
其實發(fā)生在initlizeBean，在其中會執(zhí)行BeanProcessor.postProcessAfterInitialization
具體就是AbstractAutoProxyCreator類的postProcessAfterInitialization 方法

protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
        if (beanName != null && this.targetSourcedBeans.contains(beanName)) {
            return bean;
        } else if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
            return bean;
        } else if (!this.isInfrastructureClass(bean.getClass()) && !this.shouldSkip(bean.getClass(), beanName)) {
            Object[] specificInterceptors = this.getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, (TargetSource)null);
            if (specificInterceptors != DO_NOT_PROXY) {
                this.advisedBeans.put(cacheKey, Boolean.TRUE);
                Object proxy = this.createProxy(bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
                this.proxyTypes.put(cacheKey, proxy.getClass());
                return proxy;
            } else {
                this.advisedBeans.put(cacheKey, Boolean.FALSE);
                return bean;
            }
        } else {
            this.advisedBeans.put(cacheKey, Boolean.FALSE);
            return bean;
        }
    }

執(zhí)行之后，返回的就是一個代理對象（代理對象包含一個Advisor數(shù)組，一個目標對象）

總結(jié)一下，Spring AOP動態(tài)代理的執(zhí)行過程如下
1.生成代理對象，初始化攔截器鏈(這發(fā)生在bean的生命周期initlizeBean中，生成是通過AopProxy接口，有兩個實現(xiàn)類Cglib2AopProxy，JdkDynamicAopProxy)
2.代碼中調(diào)用bean的某個方法的時候，實際上是通過代理對象調(diào)用的。調(diào)用時會獲取攔截器鏈，逐個進行匹配執(zhí)行（切面邏輯），最終通過反射的方法調(diào)用目標對象方法。