编写切面，并在ApplicationContest.xml 中相关AOP及切面的配置完全正确的情况下，运行报错如下：
Exception in thread "main" org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'usd' is expected to be of type 'com.yusys.service.UserServiceImpl' but was actually of type 'com.sun.proxy.$Proxy2'
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:378)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1086)
at com.yusys.test.Test.main(Test.java:14)
解决办法是，在AppliacationContext.xml中添加 <aop:aspectj-autoproxy proxy-target-class="true"/> 这样的配置即可解决
多次搜索获得的一个解释是：如果切入点切入的是实现类需要在spring的配置文件中加上<aop:aspectj-autoproxy proxy-target-class="true"></aop:aspectj-autoproxy>标签，代表代理的实现类而非基于接口代理