Millies, Sebastian wrote:
Hello there,
can references in composite files somehow be made dynamic? In
particular, can I define or override
the endpoints in a web service reference at run time?
My question pertains to Tuscany 1.6.
Let me go into some detail to explain the real problem I want to solve.
I have a set of items that need
to be sent to SAP backend systems. These SAP systems expose the same
interface (remote function
modules and web services). Every item has an endpointProperties
attribute that determines which
system it needs to go to.
Currently, this is done outside of Tuscany: The connection is created on
the fly using SAP Java Connector
(JCo) exploiting the endpointProperties. A remote call is made through
this connection using SAP’s proprietary
RFC protocol.
I’d like to change this to a service-based setup with Tuscany,
exploiting SAP web services. The motivation for this
is twofold: First it removes a dependency on proprietary technology
(including native code), second it opens up
the possibility to connect in a generic way to non-SAP systems that
offer compatible interfaces .
So on my side (the Tuscany SAP client side) I go through the usual steps:
a) expose function module as a web service
b) get the wsdl
c) use wsimport to create a service interface from the wsdl
d) remove JAX-WS annotations, make interface remotable, and ensure
method names are identical to operation names in wsdl
e) add an attribute of the interface type to my service
implementation and annotate it with @Reference
f) define the reference to the SAP service in my composite file
I understand (correctly, I hope, I have not tested this) that I can
override whatever endpoint is specified in the wsdl by
specifying the uri attribute on the web service binding. Here’s a
snippet from an example composite file:
<sca:reference name=/"bapiCostcenterGetList"/
promote=/"servercomponent/bapiCostcenterGetList"/>
<sca:interface.java interface=/"bapi.ZWSBAPICOSTCENTERGETLIST"//>
<!--
wsdlElement="<TargetNamespace>#wsdl.port(<SvcName>/<PortName>)" -->
<sca:binding.ws
wsdlElement=/"urn:sap-com:document:sap:rfc:functions#wsdl.port(ZWS_BAPI_COSTCENTER_GETLISTService/ZWS_BAPI_COSTCENTER_GETLIST)"/
<!-- Override service endpoint -->
uri=/"http://sapd01.me.corp.ids-scheer.com:8000/sap/bc/srt/rfc/sap/zws_bapi_costcenter_getlist/100/zws_bapi_costcenter_getlist/zws_bapi_costcenter_getlist"/
/>
</sca:reference>
As compared to the dynamic approach with hard-coded RFC calls, the
connection endpoint is now hard-wired in the composite file.
Is there a way to define Tuscany web service references with dynamic
endpoints? Or alternatively, could I perhaps use the endpointProperties
and modify the injected service proxy before making a remote call? Or
is there some entirely different route that does not involve steps a)
to f) above?
How would you deal with this type of situation?
n Sebastian
IDS Scheer Consulting GmbH
Geschäftsführer/Managing Directors: Kamyar Niroumand, Ivo Totev
Sitz/Registered office: Altenkesseler Straße 17, 66115 Saarbrücken,
Germany - Registergericht/Commercial register: Saarbrücken HRB 19681
*http://www.softwareag.com*
>
It might be possible to use service references for this. A service
reference can be serialized/deserialized to/from XML. So you could
use runtime code to create the XML-equivalent form of the service
reference that you need, then deserialize the XML to create the
service reference.
Another option is to create a node using a dynamically constructed
in-memory composite file. There's a 1.x API for doing this but
I don't recall the exact details at present.
Simon
