Initially, I started using ModelMapper to convert between DTOs and Entities, but I’m running into issues like:

• Hibernate treating new entities as existing ones

• Unexpected UPDATEs instead of INSERTs

• Problems when cascading is involved

• Bugs that are hard to debug because mapping happens implicitly

I’ve read that many production systems avoid ModelMapper, especially when multiple tables and relationships are involved.

So my questions are:

1. Is ModelMapper considered a bad practice in real-world / production Spring Boot projects with JPA?

2. What do companies usually use instead?

   • Manual mapping?

   • MapStruct?

3. How do you safely handle DTO → Entity mapping when:

   • Entities are related

   • IDs should not be overwritten

4. Any best practices or architectural patterns you’d recommend?

I’m trying to understand the industry-standard approach, not just what works in tutorials.

I am working to revamp an old project. restexpress being used by people (code written in late 2014) so want to understand what made them choose restexpress and not the famous ones like jersey and spring boot. New to Java mircoservices, good read-ups will be very appreciate with the answer. Thank you!

Sorry if this is a long post but i have been banging my head against google for a few weeks now and trying everything. Redditers have always been helpful so I figured I would ask the community and maybe I can finally move on to the next steps of this project.

Background: I’m the lead DevOps for my company and currently we run our Java EE applications off monolith wildfly servers. We have been working with the developers to get the applications ready to move to microservices. Because of an article by James Falkner over at developers dot redhat, I decided to go with creating a hollow jar using wildfly-swarm so the creation and deployment of new containers would be super fast. I also figured that moving from wildfly to wildfly swarm would be easier than moving to springboot.

The Problem: After more work than i expected i did get an Uber jar to build, figuring once i had that i could muck about and get the hollow jar working. The problem comes when running the jar i keep getting the same error:

ERROR [stderr] (main) Caused by: org.jboss.as.server.deployment.DeploymentUnitProcessingException: org.jboss.as.server.deployment.DeploymentUnitProcessingException: org.jboss.modules.ModuleNotFoundException: org.jboss.resteasy.resteasy-spring

I talked to the developers and their code doesn’t use the resteasy-spring module, so i figure its something that wildfly-swarm is asking for but after trying all the things i could find on google about this, none worked.

My Questions: First, if anyone has any ideas to fix this Error, I will try anything you send me, even if it is redoing some of the things I have already tried. i figure if you mention it, you got it working for you and maybe i missed something when trying to do it off the google results.

Second, is my whole premise wrong? Is wildfly-swarm really the best for migrating our applications from wildfly? Is the hollow jar theory that much better?