public class BeanNameAutoProxyCreator extends AbstractAutoProxyCreator

一、使用

/**
 *模拟业务接口
 */
public interface UserService {
    public void updateUser();
}

/**
 *模拟具体业务
 */
public class UserServiceImpl implements UserService{

    @Override
    public void updateUser() {
        System.out.println("$$$$$$执行业务逻辑$$$$$");
    }
}

/**
 * 模拟切面1
 */
public class SecurityInterceptor implements MethodInterceptor {
    @Override
    public Object invoke(MethodInvocation methodInvocation) throws Throwable {
        System.out.println("==========执行安全校验====================");
        return methodInvocation.proceed();
    }
}

/**
 * 模拟切面2
 */
public class LoggerBeforeAdvice implements MethodBeforeAdvice {
    @Override
    public void before(Method method, Object[] args, Object target) throws Throwable {
        System.out.println("=======保存更新日志=========");
    }
}

<beans>
   <bean class="org.springaop.chap01.UserServiceImpl" id="userService"></bean>
   <bean class="org.springaop.chap01.LoggerBeforeAdvice" id="loggerBeforeAdvice"></bean>
   <bean class="org.springaop.chap01.SecurityInterceptor" id="securityInterceptor"></bean>

   <bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
      <property name="beanNames">
         <list>
            <value>userService</value>
         </list>

      </property>
      <property name="interceptorNames">
         <list>
            <value>loggerBeforeAdvice</value>
            <value>securityInterceptor</value>
         </list>
      </property>
   </bean>
</beans>

结果：

=======保存更新日志=========

$$$$$$执行业务逻辑$$$$$

二、剖析BeanNameAutoProxyCreator设计

我们知道了Spring生成代理时，需要2个重要的信息，一个是源对象targetSource,一个是Advisor列表。

1.Spring应该是从Spring容器中，根据咱们声明的beanNames属性，当成源对象，然后代理包装

2.Advisor列表，也是从Spring容器中获取，和interceptorNames相关。

3.剖析BeanNameAutoProxyCreator实现

3.1Spring怎么完成BeanName的匹配的。

这段代码仅仅把beanName放入一个List中

抽象类中AbstractAutoProxyCreator里面有个getAdvicesAndAdvisorsForBean（）方法。这个方法会在spring的生命周期。beanPost中postProcessBeforeInstantiation被调用。

核心的匹配代码。匹配成功。则这个类需要被代理。

4.Advisor列表初始化

//2
protected Object createProxy(
      Class<?> beanClass, String beanName, Object[] specificInterceptors, TargetSource targetSource) {

   ProxyFactory proxyFactory = new ProxyFactory();
...

   Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
   for (Advisor advisor : advisors) {
      proxyFactory.addAdvisor(advisor);
   }
...
   return proxyFactory.getProxy(this.proxyClassLoader);
}