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Business Rule task not updating Java object

mikepoole

I have a business rule task that uses a drl file to update a Java object which was created in a Java Service Task prior to the rule task

I have some printlns in the functions that the drl file triggers so I am confident that the rule task is firing AND evaluating correctly.

The next step in the process is a user task. When I retrieve the values form the Java object to display on the form, they are the pre business task/drools update values

ie:
1. Create Article (my Java object (which implements Serializable)) - set size to 5 and assign Article to process variable "pvArticle"
2. Business Rule task runs and sets size to 50 (Tomcat shows the setSize() method being triggered and this.size being set to 50)
3. User task form has #{pvArticle.getSize()} as the expression - returns 5

What am I doing wrong?

Many thanks

Mike

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Comments

trademak

Hi,

That's strange indeed. I just did a small test myself and that worked as expected.
Can you share your test project?

Best regards,

mikepoole

Tijs

It is very strange indeed. I'm sure I am doing something fundamentally wrong and just not seeing it

Attached is a zip file with (hopefully) all the relevant info you need

Many thanks

Mike

DroolsTest.zip

trademak

Mike,

Your Drools example works fine with some changes.
In the code you only claim the user task, which means that the process instance doesn't even reach the business rule task, but still waits for the first user task to complete.
Also a better way to create the process engine would be:

ProcessEngine processEngine = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource("activiti.test.xml").buildProcessEngine();

And then rename your config file to activiti.test.xml. This is to be sure that the Activiti Engine uses the right Activiti config.
Also the script task you included can be removed, because you also set the variable in the Java service task.
After making these changes the test runs fine and the Java article object is updated by the business rule task.

Best regards,

mikepoole

Tijs

Many thanks for the reply

I'm a little confused by your first comment - "In the code you only claim the user task, which means that the process instance doesn't even reach the business rule task, but still waits for the first user task to complete.". (I've done the other bits - improved the ProcessEngine creation and removed the script task) with no success.

When I create the process instance, do I have to claim ALL the tasks in the process? My example requires the user task to be completed before running the business rule task as it is dependant on user input values.

How do I claim the things other than the user task to allow the process instance to reach the business rule task?

My code is currently:

<br>public class DroolsDemo {<br><br> public static void main(String[] args){<br><br>&nbsp; ProcessEngine processEngine = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource("activiti.test.xml").buildProcessEngine();<br>&nbsp; RepositoryService repositoryService = processEngine.getRepositoryService();<br>&nbsp; RuntimeService runtimeService = processEngine.getRuntimeService();<br><br>&nbsp; // Deploy the process definition (and sub processes and rules)<br>&nbsp; repositoryService.createDeployment()<br>&nbsp; .addClasspathResource("DroolsExample.bpmn20.xml")<br>&nbsp; .addClasspathResource("ArticleSize.drl")<br>&nbsp; .deploy(); <br><br>&nbsp; // Start a process instance<br>&nbsp; String procId = runtimeService.startProcessInstanceByKey("drools").getId();<br><br>&nbsp; // Get the first task<br>&nbsp; TaskService taskService = processEngine.getTaskService();&nbsp; <br>&nbsp; List<Task> tasks = taskService.createTaskQuery().processDefinitionKey("drools").list();<br>&nbsp; for (Task task : tasks) {<br>&nbsp;&nbsp; System.out.println("ProcID: " + procId + " - Task ID: " + task.getId() + " created on " + task.getCreateTime());<br>&nbsp;&nbsp; taskService.claim(task.getId(), "fozzie"); <br>&nbsp; }<br><br>&nbsp; System.out.println("DROOLS DEMO FINISHED");<br> }<br>}<br>

trademak

Hi Mike,

What I mean is that calling the claim method only changes the state of the task, it doesn't complete it.
So instead of claim, you should call the complete method and then the process instance will continue to the next activity.

Best regards,

mikepoole

Thanks Tijs

So does the user pressing the "Complete task" not do the same thing?

I want the user task to wait (having been claimed by fozzie) so that the user enters the one value, presses the "Complete task" button which will then continue the process.

Mike

trademak

Okay, maybe I didn't understand your test good enough.
In my version of the test, everything happens in that test, so you can get the feedback immediately.
When you use the Activiti Explorer to complete the task, the process instance will run on the Activiti Explorer, and that's a bit strange to my feeling.
You then only start the process instance in the test and complete it in the Activiti Explorer.

Best regards,

mikepoole

Tijs

I think I'm not doing a test, merely creating a new instance via Java then processing it all in Activiti Explorer.

Mike

trademak

Mike,

Yep. The only thing is that you then have to make sure that the service task classes used in the process definition are available in the Activiti Explorer classpath.
In addition make sure that the RulesDeployer is activated in the Activiti Engine Spring config of the Activiti Explorer.

Best regards,

mikepoole

Tijs

The applicationContext.xml file in app\apache-tomcat-6.0.32\webapps\activiti-explorer\WEB-INF has the following:

- <property name="customPostDeployers"><br>- <list><br>&nbsp; <bean class="org.activiti.engine.impl.rules.RulesDeployer" /> <br>&nbsp; </list><br>&nbsp; </property><br>

And the executable jar file that contains the service task classes is present in app\apache-tomcat-6.0.32\webapps\activiti-explorer\WEB-INF\lib\

Is there anything else I could possibly check?

Thanks

Mike

trademak

So let's walk through the test steps then.

1. You deploy a BAR file with the process definition and the rule file to Activiti using the Activiti Explorer.
2. You start a new process instance in the Activiti Explorer
3. You complete the user task in the Activiti Explorer
4. You get an error?

If you get an error in step 4, can you send me the BAR file and the JAR file for the process instance classes (maybe also a copy of the sources to make some changes)?

Best regards,

mikepoole

Tijs

I don't deploy via the BAR file into Explorer

My deployment is via the code

 repositoryService.createDeployment()<br>&nbsp; .addClasspathResource("DroolsExample.bpmn20.xml")<br>&nbsp; .addClasspathResource("ArticleSize.drl")<br>&nbsp; .deploy(); <br>

Could this be where the problem lies?

The relevant jar files are all in the explorer paths

Mike

trademak

That could be the cause of this yes. Could you try to deploy the BAR via the Explorer?

Thanks,

balu008

Hi,
i m new to activiti explorer and trying to integrate activiti with drool . how to use drl file in activiti diagram?pls help me
thanks in advance…

regards
bala

trademak

Hi,

Please take a look at the business rule task example in the Activiti in Action source code you can find here:

https://code.google.com/p/activitiinaction/source/browse/trunk/bpmn-examples/src/test/java/org/bpmnwithactiviti/chapter12/SimpleCreditCheckTest.java

Best regards,

pradnya1

Business Rule Task is marked as Experimental in Activiti 5.13 User Guide. Is this task stable now?

trademak

You can consider it as stable from a functionality point of view. We do want to improve the business rule integration at some point in time and then the attributes in the business rule task might change.

Best regards,

valep

I´ve a problem, i do not use the knowledge base, i only include in a very easy example a business task, and i´ve added a rule.
The example is getting a name in a user task, later i make an objet that only contains a boolean and i initialize it in false, and the rule says if objects attribute false then object attribute true. This rule is in a drl and i´m referring to it by its name
I´ve added the jars:
              knowledge-api-5.3
              drools-compiler-5.3.0.Final
              drools-core-5.3.0.Final
              drools-api-5.1.1
              antlr-runtime-3.1.3
              mvel2-2.1.0.drools4
to the explorer, and i´ve modified the activiti-standalone-context.xml.
I´ve deployed de project and the .drl is on the bar.
When in activiti explorer i try to charge the bar, the error "org.drools.util.compositeclassloader.clone()Lorg/drools/util/compositeclassloader;" is on and i can´t continue.
Any help?

jbarrez

No idea. This is a Drools issue - probably missing some drools dependency.

johnm

Hi all,

I know this is an old topic, but I'll add my experience here, to help anyone else whom has had the same problem.
I too had this problem, the drool rule was coded to update the obejct passed in, but back in the java code I could
not see the update.

It turns out, (unexpectedly in my mind) that the rule returns a different object reference. Using the api available in the examples to return the object from the rule, inside ruleOutputList is a new reference with the correct updates therein.

<code>
Collection<Object> ruleOutputList = (Collection<Object>) activitiRule.getRuntimeService().
    getVariable(processInstance.getId(),"rulesOutput");
</code>

I had assumed that the instances in the process variable map 'vars' (shown below) would be updated by the rule, and available for my perusal after the rule had run.

<code>
CardApplication cardApp = new CardApplication();
cardApp.setName("Miss Piggy");

ProcessInstance processInstance = activitiRule.getRuntimeService().startProcessInstanceByKey("financialReportWithNoddyRule", vars);
</code>