Invoking asynchronous BPEL process from java ui

Question

Hi,
I am invoking an asynchronous BPEL process from java ui.
I read somewhere that i can obtain an instance handler uing the lookupInstance() method of class Locator using the conversation id provided by the class NormalizedMessage.
My code looks like this
// Connect to Oracle BPEL server
Locator locator = new Locator("default","bpel");
IDeliveryService deliveryService = (IDeliveryService)locator.lookupService(IDeliveryService.SERVICE_NAME );
// Construct a normalized message and send to Oracle BPEL Process Manager
NormalizedMessage nm = new NormalizedMessage();
nm.addPart("payload", xml);
// Initiate the BPEL process
deliveryService.post("MyLoanFlow", "initiate", nm);
//Obtain the instance handler
IInstanceHandle handle = locator.lookupInstance(NormalizedMessage.CONVERSATION_ID);
But this is giving the error - can not find any instance with conversation id 'conversationId'.
Also, if i try to obtain a list of instance handles associated with a process , it does not contain the most recently created instance
IBPELProcessHandle ph = locator.lookupProcess("MyLoanFlow");
IInstanceHandle[] iHandler = ph.listInstances();
out.println(iHandler.length + "<br>");
if i invoke the process for the first time the output is 0.
can you please help me. it is urgent.

Answer 1

Hi Sudipto,
Regarding your second question,
deliveryService.post("MyLoanFlow", "initiate", nm);
IBPELProcessHandle ph = locator.lookupProcess("MyLoanFlow");
IInstanceHandle[] iHandler = ph.listInstances();
out.println(iHandler.length + "<br>");
---- returns 0 ---
This is because MyLoanFlow is an asynchronous process in your case. So the control is returned to your java block immediately after the request for a new instance is posted. And your second line of code(querying for the list of instances) is executed even before the instance is created on the server side. You can verify this in two ways:
1. try creating an instance of a synchronous process using IDeliveryService.request - this will always result in the increment since the current thread is blocked till the new instance is created.
2. for your case, you can try
Thread.currentThread().sleep(500); - just allow the server some time for completing the instance before you query it for the list of instances..
and wrt question 1,
//Obtain the instance handler
IInstanceHandle handle = locator.lookupInstance(NormalizedMessage.CONVERSATION_ID);
But this is giving the error - can not find any instance with conversation id 'conversationId'.
For setting the conversationId, you could do so by including the following inside your .bpel file
<bpelx:exec name="test-setConversationId" language="java" version="1.4">
<![CDATA[
setConversationId("conversationId");
]]>
</bpelx:exec>
The code:
IInstanceHandle ins = locator.lookupInstanceByConversationId(NormalizedMessage.CONVERSATION_ID);
should fetch you the required instance in this case.
HTH,
Anuj