JPA and Hibernate require you to write lots of Strings. You use them to create ad-hoc and named queries with JPQL, to define native SQL queries and to specify the fetching behavior in an EntityGraph. Until Java 13, the lack of multiline Strings in Java made all of these tasks either annoying to implement or…
A lot of developers complain that Java is too verbose. And I can understand that, especially for all classes that are supposed to be a basic data structure, like JPA/Hibernate entities or DTOs. So, it was no surprise that I got a lot of questions about JDK’s records feature and how you can use it…
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…
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…
