In last Spring AOP examples – advice, pointcut and advisor, you have to manually create a proxy bean (ProxyFactoryBean) for each beans whose need AOP support.
This is not an efficient way, for example, if you want all of your DAO classes in customer module to implement the AOP feature with SQL logging support (advise), then you have to create many proxy factory beans manually, as a result you just flood your bean configuration file with tons of proxy beans.
Fortunately, Spring comes with two auto proxy creators to create proxies for your beans automatically.
1. BeanNameAutoProxyCreator example
Before that, you have to create a proxy bean (ProxyFactoryBean) manually.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="customerService" class="com.mkyong.customer.services.CustomerService">
<property name="name" value="Yong Mook Kim" />
<property name="url" value="https://mkyong.com" />
</bean>
<bean id="hijackAroundMethodBeanAdvice" class="com.mkyong.aop.HijackAroundMethod" />
<bean id="customerServiceProxy"
class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="customerService" />
<property name="interceptorNames">
<list>
<value>customerAdvisor</value>
</list>
</property>
</bean>
<bean id="customerAdvisor"
class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">
<property name="mappedName" value="printName" />
<property name="advice" ref="hijackAroundMethodBeanAdvice" />
</bean>
</beans>
And get the bean with the bean with proxy name “customerServiceProxy”.
CustomerService cust = (CustomerService)appContext.getBean("customerServiceProxy");
In auto proxy mechanism, you just need to create a BeanNameAutoProxyCreator, and include all your beans (via bean name, or regular expression name) and ‘advisor’ into a single unit.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="customerService" class="com.mkyong.customer.services.CustomerService">
<property name="name" value="Yong Mook Kim" />
<property name="url" value="https://mkyong.com" />
</bean>
<bean id="hijackAroundMethodBeanAdvice" class="com.mkyong.aop.HijackAroundMethod" />
<bean id="customerAdvisor"
class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">
<property name="mappedName" value="printName" />
<property name="advice" ref="hijackAroundMethodBeanAdvice" />
</bean>
<bean
class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
<property name="beanNames">
<list>
<value>*Service</value>
</list>
</property>
<property name="interceptorNames">
<list>
<value>customerAdvisor</value>
</list>
</property>
</bean>
</beans>
Now, you can get the bean via original name “customerService”, you dun even know this bean has been proxies.
CustomerService cust = (CustomerService)appContext.getBean("customerService");
2. DefaultAdvisorAutoProxyCreator example
This DefaultAdvisorAutoProxyCreator is extremely powerful, if any of the beans is matched by an advisor, Spring will create a proxy for it automatically.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="customerService" class="com.mkyong.customer.services.CustomerService">
<property name="name" value="Yong Mook Kim" />
<property name="url" value="https://mkyong.com" />
</bean>
<bean id="hijackAroundMethodBeanAdvice" class="com.mkyong.aop.HijackAroundMethod" />
<bean id="customerAdvisor"
class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">
<property name="mappedName" value="printName" />
<property name="advice" ref="hijackAroundMethodBeanAdvice" />
</bean>
<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator" />
</beans>
This is just over power, since you don’t have control what bean should be proxy, what you can do is just trust Spring will do the best for you. Please take good care if you want to implement this into your project.
Thanks, nice post
The example works fine but I faced a small problem
that is if your class is implementing any interface
for example say
com.mkyong.customer.services.CustomerService implements Serializable
then it fails to instantiate the bean, it gives the following error
Exception in thread “main” java.lang.ClassCastException: com.sun.proxy.$Proxy0 cannot be cast to com.mkyong.customer.services.CustomerService
at com.oracle.spring.aop.test.AOPMain.main(AOPMain.java:18)
Any work around for this problem ?
It’s the best time to make some plans for the future and it’s time to be happy.
I have read this post and if I could I desire to suggest you
few interesting things or suggestions. Maybe you can write next articles referring to this article.
I wish to read even more things about it!
Valuable information. Fortunate me I discovered your site by accident, and
I am stunned why this twist of fate didn’t happened in advance! I bookmarked it.
hi Mkyong,
The Auto proxy Beans creation is explained in an overview kind of.. Could you please detail on this topic a lil bit more.
I think this page is a direct rush to the entire topic.
Regards,
Shiva Krishna.
Hi Mkyong,
I am a big fan of you page and at work your results show up often a lot ! Good job !
I have a standalone application (www.facebook.com/elitetaggerpro) and I want to use Spring AOP for some concerns I have .. like logging, security etc…
I have to say that I don’t use Spring as container but only want to use it for AOP…
I tried several things and didn’t work… when I create a service and autowire it with spring then the AOP is kicking in … probably cause Spring auto proxy that bean which makes it eligible for AOP etc…
Do you know how to achieve this ? 🙂 So I want to use Spring AOP facilityies but I manage the beans myself (not by Spring) … I made a little framework myself that does classpath scanning and wiring of instances…
Thanks in advance !
Grtz,
Sikke