Re: [aspectj-users] Passing a parameter created in the advice to the poi

["Alexander Kriegisch" <alexander@xxxxxxxxxxxxxx>]

I forgot to mention: An alternative approach might be aspects instantiated perthis or pertarget, keeping state for your objects if you want to avoid ITD.


> Hi Holger.
> 
> Some more or less extensive code snippets would be helpful, but as far as I
> understand you want to inject a value into certain objects. Unless there is
> some kind of "value store" such as a map of key/value pairs or so in your
> object, you can use ITD (inter-type definition) in order to add members to the
> desired types.
> 
> If you provide some sample code - ideally a fully functional SSCCE
> (http://sscce.org/) - I am sure someone will suggest an aspect which will show
> you how to do that based on your code. Concrete examples are usually more
> helpful than abstract ones.
> 
> Tit for tat, code for code - deal? ;-)
> 
> Regards
> -- 
> Alexander Kriegisch
> http://scrum-master.de
> 
> 
> Holger King schrieb am 18.02.2015 23:04:
> 
>> I just moved a cross-cutting-concern (the creation and closing of a 
>> non-JDBC-connection) from a web service to a Spring AOP AspectJ 
>> implementation. This aspect is being called each time any method of the 
>> web service interface is requested.
>> 
>> The problem: the pointcut (= web service implementation) needs the 
>> connection being created in the advice! But as the method signatures are 
>> defined by the web service contract (the WSDL document has been 
>> converted to Java classes via "wsdl2java" based on the contract first 
>> approach) they cannot be adapted and modified to take over the new 
>> connection parameter.
>> 
>> It's clear that the other way around where the AspectJ advice gets the 
>> parameter used in the method call matching the pointcut defintion is 
>> possible.
>> 
>> Even changing existing parameter values and passing the same arguments 
>> list (having the same types) to the implementation where the pointcut 
>> matches does work (using "&& args()" in the pointcut in combination with 
>> joinpoint.proceed(jointpoint.getArgs()))
>> 
>> But here the problem exists, as it's not sufficient to just change 
>> parameter values. Instead, a complete new variable owning the connection 
>> created in the advice needs to be accessible in the objects the pointcut 
>> matches.
>> 
>> Do you have any idea how to realize that? Or is it a complete wrong 
>> approach to do that using Java aspects - although connection handling 
>> might be a typical cross-cutting-concern?
>