is it possible to pointcut on a third party class and how?

Question

I use spring and ibatis in my project, here is my question.

I want to trace all changes like add/update/delete and log them into table T_TRACE_LOG . The table has columns: operation_type, object_type, log_content, log_date .

Here is an example record:

"add", "customer", "name='andy',age=23,...", 2012-06-14 17:04:57.410

The log_content comes from Customer.toString() , I want this process automatically, so the AOP comes into my mind.

I can't control the client code, because some uses addCustomer() and some uses insertCustomer() and others use createCustomer() . But all of them called getSqlMapClientTemplate().insert("inserCustomer", Customer) at last. So I want to pointcut on getSqlMapClientTemplate().insert() to match them all.

Here is my trying, but it doesn't work:

 <aop:pointcut  expression="execution(* org.springframework.orm.ibatis.SqlMapClientTemplate.insert(..))" id="insertLogPointCut"/>

It works If I change the expression as below:

<aop:pointcut expression="execution(* com.xxx.CustomerDaoImpl.insert(..))" id="logPointCut"/>

Because AOP compiles the "pointcut information" into class bytecode based on source code, so I think it's impossible to pointcut on the ibatis class. If it's wrong, how to handle my situation?

Here is the configuration:

<aop:aspectj-autoproxy proxy-target-class="true"/>
<bean id="traceLogger" class="com.xx.TraceLogger"/>
<aop:config>
    <aop:pointcut expression="execution(* com.xx.CustomerDaoImpl.insert(..))" id="insertLogPointCut"/>
    <aop:aspect id="logAspect" ref="traceLogger">
        <aop:after-returning method="logAfterReturning" pointcut-ref="insertLogPointCut"/>
    </aop:aspect>
</aop:config>

Answer 1

Default AOP behavior in Spring only works with interface (because it is using Java's dynamic proxy). It won't work if the pointcut is set on a concrete class.

SqlMapClientTemplate, if I remember correctly, is a class.

You have the choice of

1. using cg-lib for proxy creation, or
2. change your bean to use SqlMapClientOperations instead of SqlMapClientTemplate, and write have pointcut as "execution(* org.springframework.orm.ibatis.SqlMapClientOperations.insert(..))"

I shall recommend method 2.

And, your guess is wrong. AOP related stuff is not compiled into corresponding bytecode. They are all done in runtime (for the case in Spring)