Re: [aspectj-users] aspectj-users Digest, Vol 82, Issue 2

["Ashiwan.S." <sivakumarash007@xxxxxxxxx>]

Hi,

Thank you so much for the reply.
I guess I would have to modify the bytecode and xml specification for
the data (since the application has been written to use SOAP). If
that's the case, then I wonder if aspectj can help me at all in
modularizing this work.

I am thinking of doing something as below using aspectj.

1. Write a client side aspect which has a nested static class inside
it. The class implements a remote method. The remote method will save
the extra data in the object every time the data is available from the
HTTP request.
2. Write a server side aspect such that , before the actual EJB call,
make a remote method call to get the data and then proceed further
with the actual call.,

I understand that there is an extra overhead in making RMI call for
every request received from the Front-end to the Business logic.
But I am wondering if this will even work and can be done using aspectj.
It would be great if someone can tell me if this can be done using
aspectj . If yes, will it solve my problem. Highly appreciate any
help.

Thanks,
Ashiwan

> Message: 2
> Date: Mon, 5 Dec 2011 08:45:02 -0800
> From: Andy Clement <andrew.clement@xxxxxxxxx>
> To: aspectj-users@xxxxxxxxxxx
> Subject: Re: [aspectj-users] Using Aspect to pass a metadata as a new
>        parameter through SOAP
> Message-ID:
>        <CAAu=NOk7qhso4T1ZR-Tk-LkXvxAeXUqTkt=t1KB8=3SGgbNypg@xxxxxxxxxxxxxx>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Hi,
>
>> I don't think aspect provides a way to send an extra parameter through
>> SOAP to a VM on another machine.
>
> No there is no built in support for this in AspectJ, you'd need to
> modify the call side and server side to add/process the extra data
> respectively, but if to do that you need to modify something other
> than bytecode (e.g. an xml spec for the data being transferred) then
> it won't able to help you.
>
> But if you just need to pass something from the top to the bottom of a
> call sequence within one VM, you can use the wormhole pattern.  There
> are probably other references but a quick google turned up this one:
>
> http://www.theserverside.com/news/1365184/Part-2-The-Techniques-of-the-Trade
>
> This pattern enables you to pass something from the top to the bottom
> of the control flow without adding a parameter to all methods in
> between.
>
> cheers
> Andy
>
> On 2 December 2011 06:32, Ashiwan.S. <sivakumarash007@xxxxxxxxx> wrote:
>> Hi All,
>>
>> Sorry to bother you with email. I am new to aspectj and finding it
>> really useful to write modular cross cutting concerns.
>> I am trying to implement a distributed tracer for an enterprise web
>> application, which uses a Metadata object
>> passed along the requests. I am trying to use aspects to automate the
>> process of adding the metadata to HTTP header. But I am facing a road
>> block in using aspects.
>>
>> 1. The Architecture of my application goes as below:
>>
>> Users ----> (HTTP) FE ---------> (SOAP or RMI) BS (SOAP/RMI)----------> BE
>>
>> The application is written using J2EE. The web container talks to the
>> EJB container through SOAP. It uses the Axis implementation of the
>> soap protocol.
>>
>> 2. Till the FE-Endpoint(where it makes a call to the BS), the HTTP req
>> is passed as argument along all the function calls. So I added the
>> metadata as string in the header. This code is modular.
>>
>> 3. But from the End point at FE, when a soap call is made to BS(Web
>> service) the appropriate method is run . This is done through SOAP (as
>> SOAP messages). I have to modify all function calls in the flow from
>> FE to BS and BS to BE to carry extra parameter (which is the
>> metadata). I also need to modify the WSDL document which the SOAP
>> server, client agree upon to notify this new parameter.??I am trying
>> to figure out if this can be automated using aspect too.
>>
>> I don't think aspect provides a way to send an extra parameter through
>> SOAP to a VM on another machine.
>>
>> I would be much happy if someone can please let me know if this can be
>> done using aspects.
>> Highly appreciate any pointers or a quick work around in this regard.
>>
>> -Ashiwan
>> _______________________________________________
>> aspectj-users mailing list
>> aspectj-users@xxxxxxxxxxx
>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
>
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> End of aspectj-users Digest, Vol 82, Issue 2
> ********************************************



-- 
-Ashiwan