As you might have recognized, thoughts-on-java.org is now thorben-janssen.com. But don’t worry, it’s only a different domain name and nothing really changed. Thoughts-on-java.org gets redirected to thorben-janssen.com, all articles and courses are still there and you can keep all of your bookmarks. I also implemented a small redesign. Well, internally and especially technically, it was a…
You probably learned that you should use FetchType.LAZY for all of your associations. It ensures that Hibernate initializes an association when you use it and doesn’t spend any time getting data you don’t need. Unfortunately, this introduces a new issue. You now need to use a JOIN FETCH clause or an EntityGraph to fetch the…
EntityGraphs and JOIN FETCH clauses provide an easy and efficient way to fetch an entity and initialize its associations. But if you try to use it with a domain model that uses inheritance, you will quickly run into an issue: You can’t use this approach in a polymorphic query to fetch an association that’s defined…
Spring Boot and Spring Data JPA make the handling of transactions extremely simple. They enable you to declare your preferred transaction handling and provide seamless integration with Hibernate and JPA. The only thing you need to do is to annotate one of your methods with @Transactional. But what does that actually do? Which method(s) should…
The LazyInitializationException is one of the most common exceptions when working with Hibernate. There are a few easy ways to fix it. But unfortunately, you can also find lots of bad advice online. The proclaimed fixes often replace the exception with a hidden problem that will cause trouble in production. Some of them introduce performance…
