Java Clients for Workflow services

You can build clients for workflow services using the APIs exposed by the workflow service. The APIs enable clients to communicate with the workflow service using local and remote EJBs, SOAP, and HTTP. Worklistapp is one such Client which uses the local EJBs to access the services. When we access worklfow services from bpel it uses the WSIF bindings which is nothing but native Java wrapped as WSDL. From any Java client code we can use either Remote or SOAP client types.

Good example from Oracle is here, however this is for OC4J based, for weblgic there will be slight changes in the wf_client_config.xml and the JAR files. In wf_client_config.xml we can use t3:// instead of ormi and weblogic.jndi.WLInitialContextFactory. For JAR files better to put all the ones mentioned also in specific order, a good discussion here

Another useful link here

API Java DOC rerference here

Very useful discussion here if you are getting Nullpointer while trying to update task outcomes obtained using ITaskQueryService here

update-2/june/10
While using the java client code from portal, for a logged in user, we were getting
java.lang.SecurityException: [Security:090398]Invalid Subject: principals=[dasha
02, BusinessUnitController, SoaGroup]
at weblogic.rjvm.ResponseImpl.unmarshalReturn(ResponseImpl.java:234)
at weblogic.rmi.cluster.ClusterableRemoteRef.invoke(ClusterableRemoteRef
.java:348)
at weblogic.rmi.cluster.ClusterableRemoteRef.invoke(ClusterableRemoteRef
.java:259)
It turned out, the portal server and soa server weblogic domains needed to be enabled for global trust. And it worked by setting same credential at the Domain/Securty/Advanced page.