1. 目录

[TOC]

2. 说明

AOP动态代理是在bean初始化的过程中，在两个地方执行

  1. doCreateBean()->initializeBean()->applyBeanPostProcessorsAfterInitialization()后处理中执行
  2. 添加Bean到singletonFactories时创建的匿名内部类中。调用的时候是在doGetBean()中的getSingleton方法，执行内部类方法getEarlyBeanReference()

两个地方的处理类均为AnnotationAwareAspectJAutoProxyCreator，将原来的bean通过动态代理解析成代理之后的bean

3. 依赖分析

4. 源码分析

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@Override
public Object postProcessAfterInitialization(@Nullable Object bean, String beanName) {
    if (bean != null) {
        Object cacheKey = getCacheKey(bean.getClass(), beanName);
        if (this.earlyProxyReferences.remove(cacheKey) != bean) {
            //执行代理包装
            return wrapIfNecessary(bean, beanName, cacheKey);
        }
    }
    return bean;
}

4.1. wrapIfNecessary() 执行代理包装

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protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
    if (StringUtils.hasLength(beanName) && this.targetSourcedBeans.contains(beanName)) {
        return bean;
    }
    if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
        return bean;
    }
    if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
        this.advisedBeans.put(cacheKey, Boolean.FALSE);
        return bean;
    }

    Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);
    if (specificInterceptors != DO_NOT_PROXY) {
        this.advisedBeans.put(cacheKey, Boolean.TRUE);
        //在此处创建代理对象，
        Object proxy = createProxy(
                bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
        this.proxyTypes.put(cacheKey, proxy.getClass());
        return proxy;
    }

    this.advisedBeans.put(cacheKey, Boolean.FALSE);
    return bean;
}

4.1.1. createProxy() 创建代理

此处就是创建一个代理工厂ProxyFactory，加入源对象，在利用工厂生成代理类，具体的逻辑就不分析了。

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// 其余都不用管，只需要关注proxyFactory.setTargetSource(targetSource)和 return处
protected Object createProxy(Class<?> beanClass, @Nullable String beanName,
			@Nullable Object[] specificInterceptors, TargetSource targetSource) {

    if (this.beanFactory instanceof ConfigurableListableBeanFactory) {
        AutoProxyUtils.exposeTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName, beanClass);
    }

    ProxyFactory proxyFactory = new ProxyFactory();
    proxyFactory.copyFrom(this);

    if (!proxyFactory.isProxyTargetClass()) {
        if (shouldProxyTargetClass(beanClass, beanName)) {
            proxyFactory.setProxyTargetClass(true);
        }
        else {
            evaluateProxyInterfaces(beanClass, proxyFactory);
        }
    }

    Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
    proxyFactory.addAdvisors(advisors);
    //将代理类加入Factory工厂中
    proxyFactory.setTargetSource(targetSource);
    customizeProxyFactory(proxyFactory);

    proxyFactory.setFrozen(this.freezeProxy);
    if (advisorsPreFiltered()) {
        proxyFactory.setPreFiltered(true);
    }
    //返回代理对象，已经不涉及到spring容器相关的东西了
    //这里面就不在跟踪了，就是根据jdk或cglib创建对应的代理
    return proxyFactory.getProxy(getProxyClassLoader());
}

5. 总结

6. 注意事项