Wednesday, February 21, 2018

Caused by: java.lang.NoClassDefFoundError: javax/management/InstanceAlreadyExistsException while connecting to Oracle Database from OSGI - Adobe Experience Manager(AEM)

Caused by: java.lang.NoClassDefFoundError: javax/management/InstanceAlreadyExistsException while connecting to Oracle Database from OSGI - Adobe Experience Manager(AEM)

I was getting the below exception while connecting to the Oracle 11g database using ojbdc6.jar from OSGI in Adobe Experience Manager(AEM)

20.02.2018 15:43:39.259 *INFO* [CM Event Dispatcher (Fire ConfigurationEvent:] day.commons.datasource.jdbcpool Configuring and activating data source with name=SampleOracleDS
20.02.2018 15:43:39.260 *ERROR* [CM Event Dispatcher (Fire ConfigurationEvent:] day.commons.datasource.jdbcpool [] The activate method has thrown an exception (java.lang.IllegalArgumentException: Cannot initialize driver 'oracle.jdbc.driver.OracleDriver')
java.lang.IllegalArgumentException: Cannot initialize driver 'oracle.jdbc.driver.OracleDriver'
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.felix.scr.impl.helper.BaseMethod.invokeMethod(
at org.apache.felix.scr.impl.helper.BaseMethod.access$500(
at org.apache.felix.scr.impl.helper.BaseMethod$Resolved.invoke(
at org.apache.felix.scr.impl.helper.BaseMethod.invoke(
at org.apache.felix.scr.impl.helper.ActivateMethod.invoke(
at org.apache.felix.scr.impl.manager.SingleComponentManager.createImplementationObject(
at org.apache.felix.scr.impl.manager.SingleComponentManager.createComponent(
at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(
at org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(
at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(
at org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(
at org.apache.felix.framework.ServiceRegistrationImpl.getService(
at org.apache.felix.framework.ServiceRegistry.getService(
at org.apache.felix.framework.Felix.getService(
at org.apache.felix.framework.BundleContextImpl.getService(
at org.apache.felix.scr.impl.manager.SingleRefPair.getServiceObject(
at org.apache.felix.scr.impl.helper.BindMethod.getServiceObject(
at org.apache.felix.scr.impl.manager.DependencyManager.getServiceObject(
at org.apache.felix.scr.impl.manager.DependencyManager.invokeUnbindMethod(
at org.apache.felix.scr.impl.manager.SingleComponentManager.invokeUnbindMethod(
at org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(
at org.apache.felix.scr.impl.manager.DependencyManager$MultipleDynamicCustomizer.removedService(
at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(
at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerRemoved(
at org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.untrack(
at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.serviceChanged(
at org.apache.felix.framework.util.EventDispatcher.invokeServiceListenerCallback(
at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(
at org.apache.felix.framework.util.EventDispatcher.fireServiceEvent(
at org.apache.felix.framework.Felix.fireServiceEvent(
at org.apache.felix.framework.Felix.access$000(
at org.apache.felix.framework.Felix$1.serviceChanged(
at org.apache.felix.framework.ServiceRegistry.unregisterService(
at org.apache.felix.framework.ServiceRegistrationImpl.unregister(
at org.apache.felix.scr.impl.manager.AbstractComponentManager$3.unregister(
at org.apache.felix.scr.impl.manager.AbstractComponentManager$3.unregister(
at org.apache.felix.scr.impl.manager.RegistrationManager.changeRegistration(
at org.apache.felix.scr.impl.manager.AbstractComponentManager.unregisterService(
at org.apache.felix.scr.impl.manager.AbstractComponentManager.doDeactivate(
at org.apache.felix.scr.impl.manager.AbstractComponentManager.deactivateInternal(
at org.apache.felix.scr.impl.manager.SingleComponentManager.reconfigure(
at org.apache.felix.scr.impl.manager.SingleComponentManager.reconfigure(
at org.apache.felix.scr.impl.config.ConfigurableComponentHolder.configurationUpdated(
at org.apache.felix.scr.impl.config.ConfigurationSupport.configurationEvent(
at Source)
Caused by: java.lang.NoClassDefFoundError: javax/management/InstanceAlreadyExistsException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
... 54 common frames omitted
Caused by: java.lang.ClassNotFoundException: not found by [446]
at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(
at org.apache.felix.framework.BundleWiringImpl.access$400(
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(
at java.lang.ClassLoader.loadClass(Unknown Source)
... 59 common frames omitted

Based on the analysis the classes required by the ojdbc.jar is missing in the generated bundle.

Steps to fix the issue -

Refer the following post for complete steps to integrate Adobe Experience Manager(AEM) with Oracle Database -

Add the below Import-Package in META-INF\MANIFEST.MF file

Import-Package: javax.sql, javax.naming,, org.ietf.jgss


  • Generate the bundle by adding the above configuration(Export --> Deployable plug-ins and fragments)
  • Delete the bundle if already exist in the server
  • Install the updated bundle
  • Restart the server
  • Test the integration

How to extend the OOB Adobe Experience Manager(AEM) Hybris connector

How to extend the OOB Adobe Experience Manager(AEM) Hybris connector

This video explains the details on extending the OOB Adobe Experience Manager(AEM) Hybris connector with custom functionalities

Saturday, February 17, 2018

Approach to implement content preview environment in Adobe Experience Manager(AEM)

Approach to implement content preview environment in Adobe Experience Manager(AEM)

By default Adobe Experience Manager(AEM) not provides the preview instance to preview the content before publishing to live environment but most of the cases preview is required before publishing the content to live environment.

This post explain the approach to preview and approve the content before publishing to live environment.

The below diagram explains the preview flow


  • Author creates the content in production author and start the workflow
  • Workflow sends the content to Stage author and Publishers
  • Workflow assign the task to approver group and send the notification email
  • Approver reviews the content in stage environment and approve or reject the content (workflow)t - provides the detailed information for rejection
  • if the content is approved 
    • Workflow sends the approved content to production publishers.
  • If the content is rejected
    • Workflow assign the task to author and sends the notification
    • Author review the details and completes the workflow
    • Start the process again by correcting the content

Define Replication process step with ECMA script:

Create ecma file replicate.ecma under /etc/workflow/scripts/<<application>>  e.g. /etc/workflow/scripts/blog - This ecma script helps to replicate the content to stage environments

var workflowData = workItem.getWorkflowData();
var path = workflowData.getPayload().toString();
var session = workflowSession.getSession();

var replicator = sling.getService(;
var options = new;

for(var i=0;i<args.length;i++) {
    var agent= args[i];
    var filter = new;
    try {
        replicator.replicate(session,, path, options);
} catch(e) {
    log.error("Cannot replicate page : " + path +"on publisher. (agentId: " + agent + "): " + e);


Saturday, January 27, 2018

How to integrate Adobe Experience Manager(AEM) and SAP Hybris through OOB connector

How to integrate Adobe Experience Manager(AEM) and SAP Hybris through OOB connector

This post explains the detailed steps for AEM and Hybris integration through OOB connector. AEM comes with default Hybris connector and sample demo site(should be downloaded via package manager), the steps covered in the post is for integrating AEM 6.3 with Hybris 6.1 but the same steps works for other AEM and Hybris versions with minimal changes.

AEM Configuration:

Install JDK 8
Install AEM 6.3 server
Install, and packages from package share (I am considering geo-metrixx for demo, we.retail should be the recommended one in AEM 6.3)


Change the Hybris server version in "Day CQ Commerce Hybris Configuration", ignore to default value if the specified version is not listed.


Change the Hybris OAuth endpoint in "Hybris OAuth Handler" based on the Hybris version, /authorizationserver/oauth/token for Hybirs 6 and later and /rest/oauth/token for earlier Hybris versions   - This step can be ignored for AEM 6.3 as the connectes defaults the values based on the Hybris version selected in the previous step.


If the OAuth URL is not configured with correct value then the below exception will be displayed in error log

com.adobe.cq.commerce.hybris.impl.OAuthHandler Server did not respond with 2xx -> authentication failed.

Saturday, January 20, 2018

How to use Re-Fetching Flush Agent in Adobe Experience Manager(AEM)

This tutorial explains the details on AEM re-fetching flush agent and how to use to flush the content through re-fetching flush agent.

Re-Fetching Flush Agent

With regular flush agent, the agent flush the cache and the flushed content would only be retrieved from the publisher again after first time requested. This will create issue if the multiple parallel requests hit the dispatcher after flush as the new page is not yet cached in the dispatcher.

The re-fetching flush agent in AEM make sure the pages are requested and cached on the dispatcher immediately after replication.

Using a re-fetching flush agent allows to pre-populate the cache as it instructs the dispatcher to retrieve the pages from publish instance immediately after the flush occurs. Re-fetching flush agent works same as normal flush agent in dispatcher, additionally dispatcher sends a GET request for the content paths in the flush requests to fetch the content and update the cache.

Re-fetching flush is slow when activating lot of pages, enable the re-fetching only for specific content that is frequently accessed and activated.

The re-fetching feature is available in dispatcher since version 4.0.9

Configure Re-Fetching Flush agent

As a first step, develop a content builder that will send the flush URL’s into the flush request part of request body. The flush agent uses POST method to invoke dispatcher flush.

The sample content builder bundle can be downloaded from the below URL

The agent bundle is tested with AEM as Cloud Service Development Instance with aem-sdk-api dependency, the same can be modified to use uber-jar dependency.

Install the bundle to publisher as configuring the flush agent in the publish server is recommended— mvn clean install -PautoInstallBundle -Daem.port=4503

Now new serialization type “Re-fetch Dispatcher flush” is enabled while configuring the agents.

Define a re-fetching flush agent in publisher with required details, the process is same as normal flush agent with some additional configurations

In Settings tab select the “Serialization Type” as “Re-Fetch Dispatcher Flush”

In Extended tab add POST as the HTTP Method for sending the request to Dispatcher

In AEM Cloud Service, content is published using Sling Content Distribution . The replication agents used in previous versions of AEM are no longer used or provided, configure the required forward agent configurations to distribute the changes.

Refer the below URL for details on configuring forward distribution

Now distribute/activate a page and verify the Re-Fetching Flush Agent, the activated page is updated in dispatcher before first time requesting the page.

The re-fetching flush agent will helps to improve the performance of the frequently used critical pages, be cautious while using this feature as so many page activation will impact the AEM performance.