Eclipse & Jdeveloper Join Forces – My Bpel-enabled Flex Application

For one of my projects I need to be able to work out a RIA using Flex as the front-end, integrated with bpel processes as the back-end.

To be able to integrate these bpel processes with my flex user interface, I’ve created web service proxy clients in Jdeveloper.

These web service proxy clients can be invoked by flex using RPC or Livecycle Data Services, we’ve chosen for the last, LCDS.

After defining the architectural blue-print, I’m able to start implementing the first bpel process. In this post I will guide you through the different issues I’ve stumbled into during the development-track!

1. Installation-tips/-problems regarding Middletier with integrated BPEL :

  • Tip: Make sure that the version of the Application Server and Bpel Process Manager match the version of your JDeveloper IDE. In my case I’m working with the patched IAS Version and Jdeveloper
  • Tip: When you’re installing an OracleAS Middle Tier you need to make sure you check ‘Configure this as an Administration OC4J instance’ when you want use Enterprise Manager. This is made optional because you can work in a clustered environment, lets say your production environment, where only 1 oc4j-instance needs to server as the Administration environment
  • Problem/Solution: When installing patch on your existing Oracle Application Server you run into an exception when trying to overwrite Apache.exe => this probably means a Virus Scanner is running on your operating system which is preventing Unversial Installer of updating the file.

2. Problem/Solution Development-track, JDeveloper IDE:

  • Problem, ‘Cannot edit WebService proxy after Webservice endpoint url has changed’: I’ve defined my bpel process and web service proxy, but my middletier’s hostname has changed which means the bpel processes’ endpoint changed as well. I’ve manually updated the file, generated for the webservice proxy, and changed the endpoint url to the new hostname. If I try to edit the webservice proxy now, by choosing ‘Edit Handlers and Custom Mappings’, I get a message ‘Could Not Invoke Wizard’. The message points out that the old webservice endpoint is still used somewhere/somehow. I couldn’t find a reference to the old endpoint anywhere in the generated java-files. After some digging I finally found the cause, the webservice_proxy.proxy file. You need to change this file to be able to use the wizard again.
  • Problem/Solution: I’ve defined an XSD-file with default-attributes for my bpel process, this xsd file is validated and my bpel process is succesfully deployed BUT … If I try to create a web service proxy for this bpel process I’m getting a nullPointerException. This exception is actually true because I’ve defined the default-attribute for an xs:element with a ref-attribute, in other words, this xs:element refers to an existing defined xs:element. Solution: Define the ‘default’-attribute on the xs:element definition, using the name- and type-attribute and not the xs-element used to define your complex-type.

3. Problem/Solution Development-track, Eclipse IDE & Flex Plug-in :

  • Problem/Solution: Exception is thrown when you run your flex application ‘illegal override of rtmpChannel’. This error can be due to incompatible project files and eclipse jar-files, as in my case I imported an already existing projet in my new eclipse environment. To solve this issue I’ve created a new flex dataservices project and copied all the jar-files in the web-inf/lib folder into the imported project
  • Problem/Solution: ‘Selected wizard could not be started , Plug-in was unable to instantiate class’; this error occurs when you try to create a flex component. The solution in my case was to recreate my development environment, in other words install eclipse, flex plug-in, lcds again.
  • Problem/Solution: ‘Unable to access UserTransaction in DataService’, this errors occurs when you try to invoke the dataservice you’ve configured in your flex application using lcds. This probably means you need to configure JOTM in your tomcat server, or appliction server environment. Check out:

I will keep you posted!


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About nathalieroman