topic Re: couldn't instantiate class for a service task in Alfresco Archive

couldn't instantiate class for a service task

nbklot3 — Thu, 14 Apr 2011 03:39:36 GMT

Hi,I have created a service task in my process and created corresponding java classes for it. When I deploy my bar file and start the process, I get the below error when I hit the service task -03130003 Wrapped Exception (with status template): couldn't instantiate class com.delegate.EmailNotifyI'm

Re: couldn't instantiate class for a service task

jbarrez — Thu, 14 Apr 2011 08:07:43 GMT

The only thing you need to do is is to make sure the EmailNotify class is present in /WEB-INF/lib of activiti-rest. So, there must be an error in your jar.

Re: couldn't instantiate class for a service task

nbklot3 — Thu, 14 Apr 2011 14:45:54 GMT

Hi,
I don't see any error in my classes and it just has a simple sys out statements. I have attached the bar and jar files, can you help me figure out the issue?

Re: couldn't instantiate class for a service task

nbklot3 — Thu, 14 Apr 2011 14:48:50 GMT

attached bar file

Re: couldn't instantiate class for a service task

nbklot3 — Thu, 14 Apr 2011 21:27:15 GMT

Hi,

I found out the issue. the issue was with the jar generated by using ""Create deployment artifacts" option. I'm not sure what is missing in the jar genearted using activiti designer, but i created a jar manually using "Export" option and added it to activiti-rest lib - it worked.

If possible please check this and provide us a fix. Thanks!

Re: couldn't instantiate class for a service task

jbarrez — Fri, 15 Apr 2011 08:10:44 GMT

Moved to designer forum

Re: couldn't instantiate class for a service task

tiesebarrell — Fri, 15 Apr 2011 11:56:46 GMT

nbklot3,

the generated bar file will and should not actually contain the compiled classes. So the workaround you found by including it in the activiti-rest project is actually the correct solution: you should make sure the class is on the classpath in the runtime, because that's the way it's resolved, not from the .bar file.

Re: couldn't instantiate class for a service task

nbklot3 — Fri, 15 Apr 2011 13:14:02 GMT

Hi,

Will "create deployment artifacts" option not generate the jar file ? All I'm saying is I used the jar file generated and it didn't work. But the manual export of classes as a jar file did the magic. I didnt see any error in accessing the class files in the manual export of jar? Do I have to always follow this and not rely on the jar generated when I use create deployment artifacts option?

thanks,
Arun

Re: couldn't instantiate class for a service task

tiesebarrell — Fri, 15 Apr 2011 13:22:34 GMT

Yes, that's what I mean. The "generated jar" of Activiti Designer is not really a jar file, but a bar (business archive) file that is only meant to contain the process files. The classes are not included in Designer's export and shouldn't be. You have to make sure they're on the classpath of Activiti's engine by creating your own "real" jar file. One way to do that is to do a Maven install on the project, because Designer's projects have a Maven POM file in there by default.

Re: couldn't instantiate class for a service task

jbarrez — Mon, 18 Apr 2011 07:19:30 GMT

@Tiese: sorry for moving this post, I should have known this too (but didnt read to careful ;-))

Re: couldn't instantiate class for a service task

firebird0001 — Thu, 27 Oct 2011 12:59:26 GMT

Hi,

I have same error with one of the examples (AcmeMoneyTask).
I tried to create jar with maven and Export from eclipse and put it to libs folder, but I still get the same "couldn't instantiate" error.

Re: couldn't instantiate class for a service task

nitroin — Fri, 20 Apr 2012 15:30:20 GMT

Same problem here, I've created my own class to do the uppercase (for an easy example):

import java.util.*;
import org.activiti.engine.delegate.*;
import org.activiti.engine.RepositoryService;
import org.activiti.engine.RuntimeService;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.test.ActivitiRule;

@SuppressWarnings("unused")
public class ToUppercase implements JavaDelegate {
   
   public void execute(DelegateExecution execution) throws Exception {
     String var = (String) execution.getVariable("cliente");
     var = var.toUpperCase();
     execution.setVariable("cliente", var);
   }
   
 }

And I've deploy the .jar in the tomcat webapps folder.

But at the moment of operating it here:

[img]http://img6.imagebanana.com/img/fn7j789d/Cattura.JPG[/img]

I get the couldn't instantiate the ToUppercase class excetion.

EDIT:

We apparently have resolved the problem putting the .jar file in:
>> activiti-5.9\apps\apache-tomcat-6.0.32\webapps\activiti-explorer\WEB-INF\lib

Re: couldn't instantiate class for a service task

silvioneto — Fri, 17 Aug 2012 04:02:44 GMT

nitroin, I've just got the same problem here.

Don't you think this behavior looks like a bug?

Thanks,

Silvio Neto

Re: couldn't instantiate class for a service task

ronald_van_kuij — Fri, 17 Aug 2012 07:36:36 GMT

why is it a bug if putting the jar file correctly on the classpath solves the 'problem'?

Re: couldn't instantiate class for a service task

silvioneto — Fri, 17 Aug 2012 15:41:42 GMT

why is it a bug if putting the jar file correctly on the classpath solves the 'problem'?

Put on the both classpath, activiti-explorer and activiti-rest, is correct?

I thought explorer would use the rest API to integrate with activiti engine and just the engine would execute the service tasks. But it looks like explorer go directly to the database.

Re: couldn't instantiate class for a service task

houstoniasian — Thu, 19 Sep 2013 20:26:39 GMT

Follow up with the previous post, I also export the jar file to the activiti-explorer/lib (does not work), then activiti-explorer/WEB-INF/lib (also does not work), then myapp/WEB-INF/lib (also does not work). I run out of option

Tan

Re: couldn't instantiate class for a service task

houstoniasian — Thu, 19 Sep 2013 20:30:53 GMT

I have the same problem (Class not found). I use eclipse to export war file to Tomcat/webapps folder. I see the class StockPrice in apache-tomcat-7.0.33\webapps\myapp\WEB-INF\classes\stock\StockPrice.class. However, I still get the error "couldn't instantiate class stock.StockPrice".

Any help would be greatly appreciated. Attached is the bpmn file.

Thanks,

Tan

Re: couldn't instantiate class for a service task

houstoniasian — Thu, 19 Sep 2013 20:39:44 GMT

Never mind. I sold the problem by manually putting the class in activiti-explorer/WEB-INF/class/ folder. I create the StockPrice in myapp (my own application) and expect Activiti-Explorer to find it. I feel so stupid.

Tan

Re: couldn't instantiate class for a service task

echashnik — Thu, 25 Feb 2016 17:17:22 GMT

Did try different approaches without luck.
Java and bpmn files are attached.

Pls advice.

THX

Re: couldn't instantiate class for a service task

echashnik — Thu, 25 Feb 2016 17:25:01 GMT

Exception seen in chrome debugger:
…
org.activiti.engine.ActivitiException: couldn't instantiate class level3.activiti.designer.validation.EndPoitValidation
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
…
org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:137)
org.activiti.engine.impl.bpmn.helper.ClassDelegate.defaultInstantiateDelegate(ClassDelegate.java:242)
…
org.activiti.engine.impl.util.ReflectUtil.loadClass(ReflectUtil.java:87)
org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:134)
…
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
…