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

[Leon Ma <tutufool@xxxxxxxxx>]

No lucky to get it work in scala.

Here's my java version:

public class AopTest {

    @Test

    public void test(){

        MyJob t = new MyJob("leon");

        String result = t.talk();

        System.out.println(result);

        Assert.assertEquals(result, "LEON");

    }

}

public class MyJob {

    private String text;

    public MyJob(String value){

        text = value;

    }

    public String talk(){

        System.out.println(text);

        return text;

    }

}

@Aspect

public class MyJobAspect {

    @Around(value = "execution (com.leon.aop.MyJob.new(..))")

    public Object constructCP(ProceedingJoinPoint jp) throws Throwable {

        try {

            System.out.println("Start..");

            Object[] args = jp.getArgs();

            args[0] = args[0].toString().toUpperCase();

            return jp.proceed(args);

        } finally {

            System.out.println("End...");

        }

    }

}

The java version works well ( btw, the jp.getArgs() do return values)

No idea why scala not works.

Is there any work around? any point even before execution I can try?

Thanks

Leon

On Tue, Jun 10, 2014 at 2:05 AM, Alexander Kriegisch <alexander@xxxxxxxxxxxxxx> wrote:

>        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
>>
>>
>

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