Can we use activiti-explorer over spring boot activiti engine?

[sujeeshsvalath]

I like the Spring boot version of Activiti since it is seems to be more developer friendly for me as a Spring application developer.
But when using activiti-rest what I really miss is the features of activiti-explorer. Now I have to make a choice between following two options for activiti- development:
1. Traditional activiti-rest.war and activit-explorer.war deployments under tomcat. Package bars and libs and deploy them under libs.
2. Spring boot- my favorite.

If I choose option1, I miss Spring support. For custom end points I have to deploy my war running over activiti-rest.war and activit-explorer.war deployments.Also I can make use of activiti-explorer.
But If I choose option2 (boot support), I have no choice for making use of activiti-explorer. But my boss is asking for interface like activiti-explorer where he can see the diagram of each instance and see where it is now diagrammatically.

My query is whether it is possible to run the activiti-exploreo over spring-boot-activiti-integrated environemnt. Is there any plugin available in Spring OR can we tweak configurations inside activit-explorer to read process instances from spring-boot-embedded activiti-engine? Please share some info.

[warper]

Hi!
It is possible. Activiti explorer is available in sources. Explode sources jar, make any configuration changes you want, tweak spring configuration, add support for your processes, make new GUI etc.

[sujeeshsvalath]

Hi Warper, thanks for the reply. I am wondering if I add the following maven plugin :
<code>  
<dependency>
    <groupId>org.activiti</groupId>
    <artifactId>activiti-explorer</artifactId>
    <version>5.21.0</version>
</dependency>
</code>
in Spring boot, will I be able to run explorer over my boot process engine?

[warper]

I don't think it's that simple, you have to have web servlet support ready in your spring boot application.

[faizal-manan]

You need it embed it manually
http://blog.canang.com.my/2016/05/12/embedding-activiti-explorer-to-your-application/

[sujeeshsvalath]

Thanks Faizal,but the link is broken. I guess that would be the one am looking for. Can you please check..

[faizal-manan]

what kind of error do you get?
I had no problem with the link

[sujeeshsvalath]

Thanks Faizal, am able  to access it from another machine. Working on it now.

[faizal-manan]

hmm…
i do nothing

[sujeeshsvalath]

Hi all, I am trying to integrate rest and explorer modules. Following are the steps done:
1. Checked out the whole activiti source
2. Combined rest and explorer sources into a single project.Deleted duplicate files and updated listener in web.xml.
3.Updated pom dependencies, included dependencies from master and another project.

But When I deploy the new war I am getting the following exception:

<code>
Oct 01, 2016 9:39:44 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Exception sending context initialized event to listener instance of class org.activiti.explorer.servlet.WebConfigurer
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'navigatorManager' defined in class path resource [activiti-ui-context.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
at org.activiti.explorer.servlet.WebConfigurer.contextInitialized(WebConfigurer.java:84)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4994)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5492)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1081)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1877)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at org.activiti.explorer.navigation.TaskNavigator.<init>(TaskNavigator.java:51)
at org.activiti.explorer.navigation.NavigatorManager.afterPropertiesSet(NavigatorManager.java:61)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
… 23 more

Oct 01, 2016 9:39:46 AM org.apache.catalina.core.StandardContext listenerStop
SEVERE: Exception sending context destroyed event to listener instance of class org.activiti.explorer.servlet.WebConfigurer
java.lang.IllegalStateException: No WebApplicationContext found: no ContextLoaderListener registered?
at org.springframework.web.context.support.WebApplicationContextUtils.getRequiredWebApplicationContext(WebApplicationContextUtils.java:83)
at org.activiti.explorer.servlet.WebConfigurer.contextDestroyed(WebConfigurer.java:68)
at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:5035)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5687)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:160)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1081)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1877)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Oct 01, 2016 9:39:58 AM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: contextInitialized()
Oct 01, 2016 9:39:58 AM org.apache.catalina.core.ApplicationContext log
INFO: SessionListener: contextInitialized()
Oct 01, 2016 9:39:58 AM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: attributeAdded('org.apache.jasper.compiler.TldLocationsCache', 'org.apache.jasper.compiler.TldLocationsCache@8bc7ad')

</code>

When I checked the source, it seems that exception is because process engine is not initialized.
But I have even uncommneted activiti-custom-context.xml, but it is not working.
Somebody please help in this integration to achieve a single war with full rest and explorer support.