Custom Event Listener In AEM

Introduction

You can develop a custom event handler for Adobe Experience Manager (AEM)

Listerner Class:

package com.geometrixx.sightly.Listeners;

import java.util.Arrays;

import javax.jcr.Node;

import javax.jcr.RepositoryException;

import javax.jcr.Session;

import javax.jcr.observation.Event;

import javax.jcr.observation.EventIterator;

import javax.jcr.observation.EventListener;

import javax.jcr.observation.ObservationManager;

import org.apache.felix.scr.annotations.Component;

import org.apache.felix.scr.annotations.Reference;

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

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

import org.osgi.framework.BundleContext;

import org.osgi.service.component.ComponentContext;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import com.day.cq.tagging.JcrTagManagerFactory;

import com.day.cq.tagging.Tag;

import com.day.cq.tagging.TagManager;

@Component

public class TagListener implements EventListener {

private final Logger LOGGER = LoggerFactory

.getLogger(TagListener.class);

private BundleContext bundleContext;

@Reference

    private ResourceResolverFactory resolverFactory;

private static final String NAMESPACE = "/etc/tags/mysample";

@Reference

    JcrTagManagerFactory tmf;

private Session session;

private ObservationManager observationManager;

public void run() {

LOGGER.info("Running...");

    }

protected void activate(ComponentContext ctx) {

        this.bundleContext = ctx.getBundleContext();

          

        try

        {

                     

            //Invoke the adaptTo method to create a Session 

             ResourceResolver resourceResolver = resolverFactory.getAdministrativeResourceResolver(null);

             session = resourceResolver.adaptTo(Session.class);

               

            // Setup the event handler to respond to a new claim under content/claim.... 

                

             

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

                final String[] types = { "cq:Page","nt:unstructured"};

                final String path = "/content"; // define the path

                observationManager.addEventListener(this, Event.NODE_ADDED, path, true,

        null, null, true);

                LOGGER.info("Observing property changes to {} nodes under {}", Arrays.asList(types), path);

                          

         }

        catch(Exception e)

        {

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

              

         }

        }

protected void deactivate(ComponentContext componentContext) throws RepositoryException {

        

        if(observationManager != null) {

            observationManager.removeEventListener(this);

        }

        if (session != null) {

            session.logout();

            session = null;

          }

    }

@Override

public void onEvent(EventIterator it) {

// TODO Auto-generated method stub

LOGGER.info("IN ONEVENT!");

        

        

        try {

            while (it.hasNext()) {

               //Custom Logic Goes Here.

  

                

            }

        }catch (Exception e) {

        LOGGER.error(e.getMessage(), e);

        }

 

}

    

}

Above class is sample Event Listener Class customize the business logic in OnEvent method which is overridden 

To get more info on Events properties please refer the documentation

https://www.day.com/maven/jsr170/javadocs/jcr-2.0/javax/jcr/observation/Event.html

To get adobe article on Event Listener refer the article

https://helpx.adobe.com/experience-manager/using/tagmanager.html

Article also describes more information about TagManager Class and to use it.