DIME on J2EE

Question

It seems that WLS does not by itself support DIME attachments. Unfortunately
we find ourself in the position to implement SOAP with a DIME attachment
according to a given WSDL, as we wil be one of several parties offering the
same standardized prescribed webservice. (And yes: most of the other parties
are hooked on .NET, which is one of the reasons why this approach has been
adopted in the first place...)
What are the options open to us, if we wish to implement this Webservice on
WLS? (We value ease of use, but do not wish to spend much money, as BEA will
probably catch up supporting DIME in WLS and Weblogic Workshop in the near
future)
TIA.
Ad van Ommen
Agis Zorgverzekeringen
[email protected]

Answer 1

Thanks again Michael,
I guess its weekend time for me to implement and test this approach....
You have given me a headstart, but as a near freshman to (BEA) Webservices,
Workshop and J2EE filtering and DIME, it may take me more then the few hours
I have available this weekend.
Would it be a good idea to write a short note or whitepaper on this subject
for the BEA community?
(It seems relevant to a larger public then just you and me)
Finally I think you're dead right again about transferring large files, but
it's not in my hands. The size of 10 Mb I mentioned is the exception though.
The size will be far less then 1 Mb in most cases.
Regards
Ad vanOmmen (first name is just Ad, but with such excellent advice, you can
call me anything ;-)
[email protected]
"Michael Wooten" <[email protected]> wrote in message
news:[email protected]...
>
Hi Ad van,
Yep! It's that simple, but the devil is always in the details :-)
You'll need to create a HttpServletRequestWrapper and ServletInputStream,because
you'll need to rewrite the contents before you let it go to the respectiveweb
services Servlets in WLS and Workshop. Basically, you'll need to:
1. Change the Content-type header to text/xml (using the methods on theHttpServletRequestWrapper),
>
2. Throw away everything but the contents of the DIME record with the SOAPmessage
in it, and
3. Change the Content-length header (using the methods on theHttpServletRequestWrapper).
>
If you don't make the above changes, WLS (and Workshop) will spew forth"stack
trace obscenities", and generally be a little unhappy :-)
I would use disgression with attachment sizes though. Neither DIME, MIMEor HTTP
was designed for transfering huge files. That's why they created FTP (andGFTP)
The Java DIME package I told you about uses streaming, and will take careof all
the chunking for you.
Anyway, I think BEA is working on a "more elegant solution", as we speak.I talked
to Adam Bosworth a while back (about 2 months ago), about support for DIMEwith
both WLS and Workshop, and he was definitely all for it. Especially when Ishowed
him the differences in efficiency (and performance) with SwA using MIMEand DIME
Regards,
Mike Wooten
"Ad van Ommen" <[email protected]> wrote:
Thanks Michael,
Your solution strikes me as beautifully simple and effective. Just to
be
sure that I understand it right, I will formulate it in my own,
relatively
layman's terms. Please correct me if I'm wrong!
(The description is for my situation with an incoming DIME request)
1.
Intercept the DIME request message through a J2EE Servlet Filter
2.
Read the DIME message with the library you mentioned
2.1
The first DIME record is the SOAP message and is passed on
(The usual WLS or Workshop processing will apply to it later).
2.2
Subsequent DIME records are attachments.
They can be stored as files.
At no moment in time, the whole record needs to be in memory
(I expect records of up to approximately 10MB!)
2.3
SOAP message and files are related through the UUID.
So from the SOAP message, the filename can be derived
3.
The business logic of the webservice can find the attachments through
the
UUID.
After using it a file can be deleted.
4.
The response is simply passed by the Filter Servlet.
(If it really is this simple, one wonders why it's not offered by the
weblogic platform.)
Regards Ad
[email protected]
"Michael Wooten" <[email protected]> wrote in message
news:[email protected]...
Hi Ad van,
You might want to check out the LGPL-licensed Java DIME package at
http://onionnetworks.com/developers/index.php
I implemented a Servlet Filter (w/HttpServletRequestWrapper andHttpServletResponseWrapper
classes) that uses the generator and parser in that package, to doDIME
with both
Workshop and WLS web services. It only took me a weekend to write andtest
it,
so I think it may fit your requirement to "not spend much money, asBEA
will probably
catch up in the near future" :-)