Re: [aspectj-users] Fwd: Round advice on constructor?

["Alexander Kriegisch" <alexander@xxxxxxxxxxxxxx>]

>        jp.proceed(text..toUpperCase)

Sorry, typo. I mean text.toUpperCase, and probably you need to wrap that into an Object[], i.e.

        jp.proceed(new Object[] { text..toUpperCase })



Alexander Kriegisch schrieb am 10.06.2014 11:02:

> Hello again, Leon.
> 
> The Object[] returned by jp.getArgs() will not be passed on to jp.proceed().
> You need to bind the parameter(s) you want to modify via args(), e.g. like this
> (untested, I hope I got the Scala syntax right):
> 
> @Around("execution (com.leon.aop.MyObject.new(String, ..)) && args(text)")
> def constructCP(jp: ProceedingJoinPoint, String text): Object = {
>    try {
>        println("Start...")
>        jp.proceed(text..toUpperCase)
>    } finally {
>        println("End...")
>    }
> }
> 
> CAVEAT: If you manipulate parameters in subclass constructors this way, they
> will not be passed on to base class constructors via super() calls due to the
> execution order of
>  - preinitialization(*.new())
>  - initialization(*.new())
>  - execution(*.new()).
> 
> If you really want to catch the former two as well, you need and around()
> advice on
>  - call(*.new())
> 
> For background information see my answer and its sample output on
> http://stackoverflow.com/a/15571384/1082681.
> 
> Regards
> -- 
> Alexander Kriegisch
> http://scrum-master.de
> 
> 
> Leon Ma schrieb am 10.06.2014 10:10:
> 
>> I've successfully used round advice to intercept input parameter for a method.
>> 
>> 
>> However, it seems constructor does not work for me. Here're my test: (It's in
>> scala, but should be easy to understand)
>> 
>> 
>> class MyObjectTest extends FlatSpecLike with Matchers {
>> 
>> 
>>   "MyObjectAspect" should "work" in {
>> 
>>     val t = new MyObject("leon")
>> 
>>     val result = t.talk()
>> 
>>     println(result)
>> 
>>     result should be("LEON")
>> 
>>   }
>> 
>> }
>> 
>> 
>> class MyObject(text: String) {
>> 
>> 
>>   def talk(): String = {
>> 
>>     println("MyObject " + text)
>> 
>>     text
>> 
>>   }
>> 
>> }
>> 
>> 
>> @Aspect
>> 
>> class MyObjectAspect {
>> 
>> 
>>   @Around(value = "execution (com.leon.aop.MyObject.new(..))")
>> 
>>   def constructCP(jp: ProceedingJoinPoint): Object = {
>> 
>> 
>>     try {
>> 
>>       println("Start...")
>> 
>>       val args = jp.getArgs
>> 
>>       args(0) = args(0).toString.toUpperCase
>> 
>>       jp.proceed(args)
>> 
>>     } finally {
>> 
>>       println("End...")
>> 
>>     }
>> 
>> 
>>   }
>> 
>> 
>> }
>> 
>> 
>> output:
>> 
>> 
>> Start...
>> 
>> End...
>> 
>> MyObject leon
>> 
>> leon
>> 
>> 
>> "[leon]" was not equal to "[LEON]"
>> 
>> org.scalatest.exceptions.TestFailedException: "[leon]" was not equal to
>> "[LEON]"
>> 
>> at
>> org.scalatest.MatchersHelper$.newTestFailedException(MatchersHelper.scala:160)
>> 
>> at
>> org.scalatest.Matchers$ShouldMethodHelper$.shouldMatcher(Matchers.scala:6141)
>> 
>> at org.scalatest.Matchers$AnyShouldWrapper.should(Matchers.scala:6175)
>> 
>> at com.leon.aop.MyObjectTest$$anonfun$1.apply$mcV$sp(ConstructorTest.scala:18)
>> 
>> 
>> Anything wrong?
>> 
>> 
>> Thanks
>> 
>> 
>> Leon
>> 
>>
>