JCR event listener is not working in aem 6.4

[vitis90]

Hi all,

Looks like the JCR event listener in 6.4 is broken. Events dont get triggered at all. Is anyone else facing the same issue? Is there any solution?

[Peter_Puzanovs]

Dear Sir or Madam,

That's impossible, if your AEM system managed to install it means that JCR Event Listener has been working(or worked).

Would it be possible that any of your code has broken Listener or your code incorrectly hooks into Listeners?

Regards,

Peter

[arunpatidar]

Hi,

Are creating your own listeners, if yes, how you are getting session?

[smacdonald2008]

Exactly - this is where the issue is. I will test this on 6.4.

[smacdonald2008]

I got this working with the following code. The result was this - which shows the logic working: 

02.11.2018 11:08:47.895 *INFO* [sling-oak-observation-19] SimpleResourceListener something has been added : /apps/example/templates

02.11.2018 11:08:47.895 *INFO* [sling-oak-observation-19] SimpleResourceListener something has been added : /apps/example/templates/jcr:primaryType

02.11.2018 11:08:47.895 *INFO* [sling-oak-observation-19] SimpleResourceListener something has been added : /apps/example/templates/jcr:createdBy

02.11.2018 11:08:47.895 *INFO* [sling-oak-observation-19] SimpleResourceListener something has been added : /apps/example/templates/jcr:created

Java code:

package com.adobe.community.listeners;

import java.util.HashMap;

import java.util.Map;

import javax.jcr.Property;

import javax.jcr.RepositoryException;

import javax.jcr.Session;

import javax.jcr.observation.Event;

import javax.jcr.observation.EventListener;

import javax.jcr.observation.ObservationManager;

import org.apache.sling.api.resource.LoginException;

import org.apache.sling.api.resource.Resource;

import org.apache.sling.api.resource.ResourceResolver;

import org.apache.sling.api.resource.ResourceResolverFactory;

import org.osgi.service.component.annotations.Activate;

import org.osgi.service.component.annotations.Component;

import org.osgi.service.component.annotations.Deactivate;

import org.osgi.service.component.annotations.Modified;

import org.osgi.service.component.annotations.Reference;

import org.osgi.service.metatype.annotations.Designate;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.osgi.service.component.ComponentContext;

import javax.jcr.observation.EventIterator ;

@Component(immediate=true,

service= EventListener.class)

public class SimpleResourceListener implements EventListener{

    Logger log = LoggerFactory.getLogger(this.getClass());

     private Session adminSession;

     @Reference

     org.apache.sling.jcr.api.SlingRepository repository;

     @Activate

     public void activate(ComponentContext context) throws Exception {

     log.info("activating ExampleObservation");

     try {

       adminSession = repository.loginAdministrative(null);

       adminSession.getWorkspace().getObservationManager().addEventListener(

          this, //handler

          Event.PROPERTY_ADDED|Event.NODE_ADDED, //binary combination of event types

          "/apps/example", //path

          true, //is Deep?

          null, //uuids filter

          null, //nodetypes filter

          false);

      } catch (RepositoryException e){

      log.error("unable to register session",e);

      throw new Exception(e);

     }

    }

    @Deactivate

    public void deactivate(){

     if (adminSession != null){

      adminSession.logout();

     }

    }

    public void onEvent(EventIterator eventIterator) {

      try {

        while (eventIterator.hasNext()){

          log.info("something has been added : {}", eventIterator.nextEvent().getPath());

        }

       } catch(RepositoryException e){

       log.error("Error while treating events",e);

      }

     }

    }

I tried replacing use of login with a system user - that did not fire the event. So I whitelisted the bundle and this works. Try that.

[smacdonald2008]

Tested again - this session (even though system user belongs to admin group and has all required permissions) does not fire off the event:

Map<String, Object> param = new HashMap<String, Object>();

        param.put(ResourceResolverFactory.SUBSERVICE, "datawrite");

        ResourceResolver resolver = null;

        try {

            //Invoke the adaptTo method to create a Session used to create a QueryManager

            resolver = resolverFactory.getServiceResourceResolver(param);

            session = resolver.adaptTo(Session.class);

[vitis90]

Hi Scott,

I'm actually getting a session object in this way, using the subservice and system user. It is the recommended way right? Is there any workaround for this? I wouldn't want to get the session by passing null object because it is not the secure way.

[vitis90]

I'm getting via subservice and a system user, the usual way.

[vitis90]

hi Scott, even this code didn't work

adminSession = repository.loginAdministrative(null);

observationManager = adminSession.getWorkspace().getObservationManager();

observationManager.addEventListener(this, Event.NODE_ADDED | Event.NODE_MOVED | Event.NODE_REMOVED, "/content/dam/products",true, null, null, false);

[arunpatidar · Accepted solution]

Hi Scott,

It does work with system user as well. But you need JCR repository session in order to get jcr events work.

Below code works for me.

aem63app-repo/SampleJCREvent.java at master · arunpatidar02/aem63app-repo · GitHub

@Reference
	private SlingRepository repository;
	private Session session;
	private ObservationManager observationManager;
	protected void activate(ComponentContext context) throws Exception {
	session = repository.loginService("readService",null);
	observationManager = session.getWorkspace().getObservationManager();
	observationManager.addEventListener(this, Event.PROPERTY_ADDED | Event.PROPERTY_CHANGED, "/content/AEM64App/fr", true, null,
	new String[]{"cq:PageContent","nt:unstructured"} , true);
	logger.info("*************added JCR event listener");
	}

[smacdonald2008]

that is great! We will create a 6.4 HELXP article and show this code.

[smacdonald2008]

Confirmed this output was created:  com.adobe.community.listeners.SimpleResourceListener something has been added : /apps/example/config

Code:

package com.adobe.community.listeners;

import java.util.HashMap;

import java.util.Map;

import javax.jcr.Property;

import javax.jcr.RepositoryException;

import javax.jcr.Session;

import javax.jcr.observation.Event;

import javax.jcr.observation.EventListener;

import javax.jcr.observation.ObservationManager;

import org.apache.sling.api.resource.LoginException;

import org.apache.sling.api.resource.Resource;

import org.apache.sling.api.resource.ResourceResolver;

import org.apache.sling.api.resource.ResourceResolverFactory;

import org.osgi.service.component.annotations.Activate;

import org.osgi.service.component.annotations.Component;

import org.osgi.service.component.annotations.Deactivate;

import org.osgi.service.component.annotations.Modified;

import org.osgi.service.component.annotations.Reference;

import org.osgi.service.metatype.annotations.Designate;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.osgi.service.component.ComponentContext;

import javax.jcr.observation.EventIterator ;

@Component(immediate=true,

service= EventListener.class)

public class SimpleResourceListener implements EventListener{

    Logger log = LoggerFactory.getLogger(this.getClass());

     private Session adminSession;

     @Reference

     org.apache.sling.jcr.api.SlingRepository repository;

     @Activate

     public void activate(ComponentContext context) throws Exception {

     log.info("activating ExampleObservation");

     try {

   adminSession = repository.loginService("datawrite",null);

         adminSession.getWorkspace().getObservationManager().addEventListener(

          this, //handler

          Event.PROPERTY_ADDED|Event.NODE_ADDED, //binary combination of event types

          "/apps/example", //path

          true, //is Deep?

          null, //uuids filter

          null, //nodetypes filter

          false);

     } catch (RepositoryException e){

      log.error("unable to register session",e);

      throw new Exception(e);

     }

    }

    @Deactivate

    public void deactivate(){

     if (adminSession != null){

      adminSession.logout();

     }

    }

    public void onEvent(EventIterator eventIterator) {

      try {

        while (eventIterator.hasNext()){

          log.info("something has been added : {}", eventIterator.nextEvent().getPath());

        }

       } catch(RepositoryException e){

       log.error("Error while treating events",e);

      }

     }

    }

6.4 article  -- https://helpx.adobe.com/experience-manager/using/aem64_event_listener.html

[ajinkayk6258253]

this solution is not  working for 6.5

[arunpatidar]

Hi,

What error are you getting? Is bundle active?

[ajinkayk6258253]

not getting any error. bundle is also active, eventlistner not working. it worked with administrativelogin.but not with servicelogin

[gangula2018]

It's 2021 Same problem on Cloud AEM when switched to version 2021.3.5087.20210322T071003Z. On version: AEM v2021.1.4794.20210121T150042Z. it was working fine.

[gangula2018]

it is 2021 - Exactly the same problem reoccurred. On AEM Cloud when switched to last sdk version: 2021.3.5087.20210322T071003Z. it stopped working. Previously with version: 2021.1.4794.20210121T150042Z it was working as expected.

[arunpatidar]

Hi,

I've just checked below example in 6.5, working fine for me.

I created a system user arch17sysuser, gave CRUD permissions, created mapping with sub service readService

mapping look like below where com.acc.arch17.arch17.core is bundle symbolic name.

com.acc.arch17.arch17.core:readService=arch17sysuser

aem63app-repo/SampleJCREvent.java at master · arunpatidar02/aem63app-repo · GitHub

[karthick1356]

@arunpatidar 

onEvent method never triggered for me. is it still working for you?

bcz I followed the same from here:aem63app-repo/SampleJCREvent.java at master · arunpatidar02/aem63app-repo · GitHub.

I saw the log event that get registered and unregistered.

public void onEvent(EventIterator it) {
    while (it.hasNext()) {
        Event event = it.nextEvent();
        try {
            logger.info("********INSIDE TRY *****");
            Property changedProperty = session.getProperty(event.getPath());
            if (changedProperty.getName().equalsIgnoreCase("jcr:title")
                    && !changedProperty.getString().endsWith("!")) {
                changedProperty.setValue(changedProperty.getString() + "!");
                logger.info("*************Property updated: {}", event.getPath());
                session.save();
            }
        }
        catch (Exception e) {
            logger.error(e.getMessage(), e);
        }
    }
}

[arunpatidar]

HI @karthick1356 
Which AEM version are you using?

[karthick1356]

Hi @arunpatidar , AEM version is 6.5.13.