Adaptive RFC and Locking Objects from WD Java

Question

Hi,
There are some pieces of information available on this subject but no coherent and easy to follow "manual". Also some questions remain.
I'd rate this a very important, i.e. "business critical" problem. Therefore I would appreciate your help to get things sorted in this thread.
So let's start with a summary of what I think I understood so far (corrections welcome!):
- You can call RFCs from WebDynpro and locking will work (on the ABAP side).
- Once you release your JCo connection the locks will be released, though.
- Therefore, to keep a lock in between requests you have to keep the connection.
- You can keep the connection by passing WDModelScopeType.APPLICATION_SCOPE or WDModelScopeType.COMPONENT_SCOPE to the constructor of the model class.
- You can lookup the default scope for a model using
     WDModelScopeType defaultScope = WDModelFactory.lookupDefaultScopeForModel((Class) modelClazz);
Now suppose you have many users, each holding some locks.
Would you not easily run out of JCo connections? On the other hand by default WebDynpro RFC Models seem to keep a connection per application instance (= user session).
Using WDModelScopeType: Do you really need to code this or can you just configure this during design time for the deployment?
blog=/pub/wlg/1061 claims the default is APPLICATION_SCOPE.
Will connections (and thus locks) be released automatically on an HttpSession timeout? I guess so because this means the end of the application and therefore end of scope WDModelScopeType.APPLICATION_SCOPE and WDModelScopeType.COMPONENT_SCOPE.
I'm also not clear about this:
/people/sap.user72/blog/2005/01/08/adaptive-rfc-models-in-web-dynprosome-pointers
"But to ensure that the record remains locked it is necessary reserve the connection that was used for locking and be made unavailable for other models and also the connection should remain open as long as the lifetime of the screen. This becomes similar to locking records through SAP Gui . This can be easily achieved by having separate models for locking RFCs defined with APPLICATION_SCOPE and isolating its connection by not grouping with other model objects."
What does "reserve the connection" mean?
Suppose you lock some object and afterwards want to allow the user to request more information about this or other objects.
Would you need to use a different connection for that?
Suppose you want to lock two objects.
Would you need to use two different connections for that?
Suppose you want to edit both objects and save the changes inside one transaction (with atomicity). A transaction normally is associated with a single connection (unless XA protocol is used). So how would this work?
What will cause the locks to be released?
- Application expiration (timeout)
- RFC that explicitely releases locks
- Transaction commit/rollback (?)
Reference:
I found some of the information and further pointers in the blog mentioned above and here:
Disconnect method
Looking forward to your replies
Markus
Message was edited by: Markus Wissmann
Another thread with the same topic and no final answers:
Handling object locking in R/3 from WD through RFC
Message was edited by: Markus Wissmann

Answer 1

Hi,
This for If you send destination params are different u sent it thru URL param only.
For that u need generate URL by using the application .
For that purpose u need to create two applications u can call the first application in second application u can create URL and send Destination params with URL only.
Other wise u can create the par file that would be configured in portal and thru worksets u can pass the params like u mention the destinations.
Or at the time generationg URLS only u can add the destination names.
Thanks,
Lohi.