Issue facing in AEM Workflow Custom Process Step

[NavyaVo]

We have written a custom workflow process that’s supposed to resize an image and create a new rendition whenever an asset is uploaded under /content/dam/projects. The code executes without throwing any errors, but the resized image isn't getting created, and I don’t see any new rendition added. Here's the snippet:

@Override
public void execute(WorkItem workItem, Session session, MetaDataMap metaData) {
    try {
        String path = workItem.getWorkflowData().getPayload().toString();
        ResourceResolver resolver = ...; // Get from service user or workflow session
        Resource resource = resolver.getResource(path);

        if (resource != null && resource.adaptTo(Asset.class) != null) {
            Asset asset = resource.adaptTo(Asset.class);
            Rendition original = asset.getOriginal();

            try (InputStream input = original.getStream()) {
                Layer layer = new Layer(input);
                layer.resize(800, 600); // Resize to 800x600

                asset.addRendition("custom-resized", layer.getInputStream(), "image/jpeg");
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

I am not seeing any errors, but the resized rendition is not being saved. What could be the issue here?

[ShivamKumar]

Hi @NavyaVo ,

I think the logic that you have written is good, you just need to add below code after asset.addRendition() line to save all the changes.

resolver.commit();

It saves all the unsaved changes you’ve made using that Resource Resolver to the JCR repository (AEM’s content database). 

Let me know if it works or you need more help.

Thanks.

[SantoshSai · Accepted solution]

Hi @NavyaVo,

I’m not entirely sure, but a few things might be going wrong here:

Maybe the ResourceResolver you're using doesn’t have the necessary permissions to write to the DAM. If it’s not coming from a properly configured service user, the rendition might never get saved—even if no error is thrown.

You might want to check if the resolver is obtained like this:

resourceResolverFactory.getServiceResourceResolver(
  Collections.singletonMap(ResourceResolverFactory.SUBSERVICE, "your-subservice-name")
)

And make sure the service user has write access to /content/dam.

It’s possible that Layer isn't resizing the image correctly. This can happen if the input stream is invalid, or if the image format isn’t fully supported.

Maybe add a quick log like:

log.info("Original dimensions: {}x{}", layer.getWidth(), layer.getHeight());

Just to confirm the resize is actually happening.

Hope that helps!

[NavyaVo]

Thank you!
I actually tried adding resolver.commit() after asset.addRendition(), but unfortunately that wasn’t the issue in this case.

The root cause turned out to be that theResourceResolver I was using didn’t have sufficient permissions to write to /content/dam. Even with the commit call, the changes weren’t getting saved because the resolver itself wasn’t authorized to make those modifications.

Once I switched to a properly mapped service user with the right permissions, everything worked as expected - even without manually calling commit() .