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Vishal_Kagde
New Participant
May 28, 2025
Solved

Unable to trigger replication from custom workflow step

  • May 28, 2025
  • 4 replies
  • 708 views

Hey everyone,
I am working on an AEM 6.5.17 and trying to trigger content replication to the publish instance from a custom workflow step. I have injected the Replicator service in my workflow process implementation, but when the step is executed, I am getting a NullPointerException when calling replicator.replicate(...).

Here is a simple code:

public class CustomReplicationStep implements WorkflowProcess {
@3214626
private Replicator replicator;

@9944223
public void execute(WorkItem workItem, WorkflowSession workflowSession, MetaDataMap args) {
String payloadPath = workItem.getWorkflowData().getPayload().toString();
try {
Session session = workflowSession.adaptTo(Session.class);
replicator.replicate(session, ReplicationActionType.ACTIVATE, payloadPath);
} catch (Exception e) {
log.error("Replication failed", e);
}
}
}

 

I registered this workflow properly in OSGI, and it appears in the workflow model, but the error suggests the replicator is null. I even tried switching to @586265, but it didn’t help.

Has anyone faced this before? Do I need to handle service injection differently inside workflow steps?

Thanks in advance!

Best answer by SantoshSai

Hi @vishal_kagde,

The problem is that OSGi service injection (like @Reference) does not work if you're instantiating your class manually or it's not registered properly as an OSGi component.

Try the following approach to see if it resolves the issue:

  1. Make sure your class is declared as an OSGi component with proper annotations:

    @Component(service = WorkflowProcess.class, property = {"process.label=Custom Replication Step"}) public class CustomReplicationStep implements WorkflowProcess { @Reference private Replicator replicator; @Override public void execute(WorkItem workItem, WorkflowSession workflowSession, MetaDataMap args) throws WorkflowException { try { String path = workItem.getWorkflowData().getPayload().toString(); Session session = workflowSession.adaptTo(Session.class); replicator.replicate(session, ReplicationActionType.ACTIVATE, path); } catch (Exception e) { throw new WorkflowException("Replication failed", e); } } }

  1. Ensure the bundle is active, and check OSGi console at /system/console/components to confirm your workflow step is registered and active.

  2. One last thing worth to check: The session used for replication must have the necessary permissions. Ensure that the service user associated with the workflow has replication rights.

Official Adobe Documentation:

Hope that helps!

4 replies

rahulp76079001
rahulp76079001
New Participant
June 17, 2025

It seems your session is not having replication permission for the particular resource you are trying to replicate.

AmitVishwakarma
AmitVishwakarma
New Participant
May 28, 2025

Hi @vishal_kagde ,

Please follow below steps:

Step 1: Use Correct OSGi Annotations and Service Injection

package com.yourcompany.core.workflow; import com.adobe.granite.workflow.WorkflowException; import com.adobe.granite.workflow.exec.WorkItem; import com.adobe.granite.workflow.exec.WorkflowProcess; import com.adobe.granite.workflow.metadata.MetaDataMap; import com.day.cq.replication.ReplicationActionType; import com.day.cq.replication.Replicator; import org.apache.sling.api.resource.ResourceResolver; import org.apache.sling.api.resource.ResourceResolverFactory; import org.osgi.service.component.annotations.Component; import org.osgi.service.component.annotations.Reference; import javax.jcr.Session; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.HashMap; import java.util.Map; @Component(service = WorkflowProcess.class, property = {"process.label=Custom Page Replication Step"}) public class CustomReplicationStep implements WorkflowProcess { private static final Logger log = LoggerFactory.getLogger(CustomReplicationStep.class); @Reference private Replicator replicator; @Reference private ResourceResolverFactory resolverFactory; private static final String SERVICE_USER = "workflow-service-user"; @Override public void execute(WorkItem workItem, com.adobe.granite.workflow.exec.WorkflowSession workflowSession, MetaDataMap args) throws WorkflowException { String payloadPath = workItem.getWorkflowData().getPayload().toString(); log.info("Replicating path: {}", payloadPath); Map<String, Object> authMap = new HashMap<>(); authMap.put(ResourceResolverFactory.SUBSERVICE, SERVICE_USER); try (ResourceResolver resolver = resolverFactory.getServiceResourceResolver(authMap)) { Session session = resolver.adaptTo(Session.class); replicator.replicate(session, ReplicationActionType.ACTIVATE, payloadPath); log.info("Replication succeeded for path: {}", payloadPath); } catch (Exception e) { log.error("Replication failed", e); throw new WorkflowException("Replication failed for: " + payloadPath, e); } } }

Step 2: Create a Service User Mapping

Go to /system/console/configMgr

Search: Apache Sling Service User Mapper Service Amendment

Add entry:

com.yourcompany.core.workflow:workflow-service-user=replication-service

 

Step 3: Create Service User and Assign Permissions

Go to Useradmin (/useradmin)

Create system user: replication-service

Assign /content and replication rights:

  - jcr:read

  - replicate

  - replicate:Activate

 

Look in error.log for:

Replicating path: /content/yourpage Replication succeeded for path: /content/yourpage

 

Regards,
Amit

    kapil_rajoria
    kapil_rajoria
    New Participant
    May 28, 2025

    Hi @vishal_kagde ,
    For @reference to work, I hope your class is annotated as an OSGI component by using the @component annotation.

    @Component(service = WorkflowProcess.class, property = {"process.label=Custom Replication Step"}) public class CustomReplicationStep implements WorkflowProcess {

     
    After this, If this doesn't work, check if your bundle (http://localhost:4502/system/console/bundles) is active or not and share the snapshot here, if there's any issue.

      SantoshSai
      SantoshSaiAccepted solution
      New Participant
      May 28, 2025

      Hi @vishal_kagde,

      The problem is that OSGi service injection (like @Reference) does not work if you're instantiating your class manually or it's not registered properly as an OSGi component.

      Try the following approach to see if it resolves the issue:

      1. Make sure your class is declared as an OSGi component with proper annotations:

        @Component(service = WorkflowProcess.class, property = {"process.label=Custom Replication Step"}) public class CustomReplicationStep implements WorkflowProcess { @Reference private Replicator replicator; @Override public void execute(WorkItem workItem, WorkflowSession workflowSession, MetaDataMap args) throws WorkflowException { try { String path = workItem.getWorkflowData().getPayload().toString(); Session session = workflowSession.adaptTo(Session.class); replicator.replicate(session, ReplicationActionType.ACTIVATE, path); } catch (Exception e) { throw new WorkflowException("Replication failed", e); } } }

      1. Ensure the bundle is active, and check OSGi console at /system/console/components to confirm your workflow step is registered and active.

      2. One last thing worth to check: The session used for replication must have the necessary permissions. Ensure that the service user associated with the workflow has replication rights.

      Official Adobe Documentation:

      Hope that helps!

      Santosh Sai
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