除了在配置文件中使用 <aop:config> 或者 <aop:aspectj-autoproxy> 来声明切面。 同样可以通过编程方式来创建代理通知（advise）目标对象。关于Spring AOP API的详细介绍，请参看下一章。这里我们重点介绍自动创建代理。
类 org.springframework.aop.aspectj.annotation.AspectJProxyFactory
可以为@AspectJ切面的目标对象创建一个代理。该类的基本用法非常简单，示例如下。请参看Javadoc获取更详细的信息。
// create a factory that can generate a proxy for the given target object AspectJProxyFactory factory = new AspectJProxyFactory(targetObject); // add an aspect, the class must be an @AspectJ aspect // you can call this as many times as you need with different aspects factory.addAspect(SecurityManager.class); // you can also add existing aspect instances, the type of the object supplied must be an @AspectJ aspect factory.addAspect(usageTracker); // now get the proxy object... MyInterfaceType proxy = factory.getProxy();