Using Web Dynpro authentication for a Web Service call

Question

Hi all,
I want to develop a Web Dynpro that calls a Web Service running on the same Web AS (7.0). The Web Dynpro will be integrated in a Portal. The web service that has to be called is automatically generated when we create a guided procedure :
http://help.sap.com/saphelp_nw2004s/helpdata/en/44/44c59fd7c72e84e10000000a155369/frameset.htm
In my Web Dynpro, I imported the WSDL of this WS and created a model.
The first time I tried to call the WS in my Web Dynpro I got an authentication error :
Service call exception; nested exception is: com.sap.engine.services.webservices.jaxrpc.exceptions.InvalidResponseCodeException: Invalid Response Code: (401) Unauthorized. The requested URL was:"http://<myHostName>:50100/GPRuntimeFacadeWS/GPProcessExposing?style=document&pid=CA544E9B629A11DB91480017A48D672A&pver=0.5"
So I hard-coded an HTTP authentication :
     model._setUser("myWASuser");
     model._setPassword("myPassword");
And the Web Service call now works.
Now the next step is that the WS call is made by the user that runs the Web Dynpro. So I found this documentation :
http://help.sap.com/saphelp_nw04/helpdata/en/59/e8e95d1eba48dfa86ae91ad8816f5d/frameset.htm
It would resolve my authentication problem, AND the transport issue : at the moment the Web Service URL is stored in the Logical Port of the WD model, and at transport time, a rebuild of the WD project will be needed.
So I applied what is said in the doc : from the point of view of the Web Service consumer, I just had to add :
    model._setHTTPDestinationName("STARTGP");
(where STARTGP is the name of the destination I created in the Visual Administrator with a "Logon Ticket" authentication.)
before the execute(), and I removed my hardcoded authentication.
Unfortunately, nothing changes... I still get a 401 authentication error.
Does anyone have an idea about this ? Or maybe a workaround ?
Thanks in advance for any suggestion.
Regards,
Julien

Answer 1

Hello Julien,
I have a scenario similar to yours. A client webdynpro application accessing a EJB methods exposed as web service. Those EJB's methods calls R3 RFC's. The client requirements' was to allow SSO through all the layers (Webdynpro -> EJB WS -> RFC). The Webdynpro and EJB's are deployed on the same WAS.
Solution:
1 - Create a RFC Destination on Visual Administration provide the R3 connection parameters and set the Authentication for "Current User (Logon Ticket)". Save your Destination;
2 - In your EJB Project open your Web Service Configuration, on the Security page, set:
    Authentication Mechanism: HTTP Authentication
    Basic (username/password)
    Use SAP Logon Ticket
3 - In your EJB, implement the following code to create JCO Client for the RFC invocations:
Object obj = ctx.lookup(DestinationService.JNDI_KEY);
    DestinationService dstService = (DestinationService) obj;
    RFCDestination dst = (RFCDestination) dstService.getDestination("RFC", "<YOUR_RFC_DESTINATION_NAME>");
    Properties jcoProperties = dst.getJCoProperties();
    JCO.Client jcoClient = JCO.createClient(jcoProperties);
4 - In your EAR Project, open your "application-j2ee-engine.xml" and add the References:
     "tc/sec/destinations/service" as Service
     "tc/sec/destinations/interface" as Interface.
5 - Create your EAR File and Deploy;
6 - Check if the web service now requires Authentication: go to http://<host>:<port>/index.html and click on Web Services Navigator. Test your Web Service. Your Web Service should requiere you to log in before execute the test;
7 - Go back to your Visual Administrator and create a HTTP Destination. Provide your WS URL (should be something like "http://<host>:<port>/<WS_NAME>/Config1?style=document"). Choose Authentication: Logon Ticket. Save your Destination;
8 - Go to your webdynpro project, import your WS Model. (If you have already created it, you have to delete it and import it again, refer to this blog on how to reimport WS Models: /people/bertram.ganz/blog/2005/10/10/how-to-reimport-web-service-models-in-web-dynpro-for-java  How To Reimport Web Service Models in Web Dynpro for Java );
9 - Open your model's Logical Ports node, go to the Security tab, and choose "Use SAP Logon Ticket";
10 - In your webdynpro code, before you call the ws invocation (should be something like that: <YOUR_NODE_DEFINITION>.modelObject().execute();), include the following line:
<YOUR_NODE_DEFINITION>.modelObject()._setHTTPDestinationName("<YOUR_HTTP_DESTINATION_NAME>");
11 - Save All Metadata and deploy your Webdynpro App. Test your results.
I hope it helps you, as the documentation on how to implement this scenario is scattered through the SDN and all the SAP help portal.
Best regards,
Paulo.