JPA

Part 13: "The Catalog" — Spring Boot 4.1, JPA and REST in Kotlin

Kabir's first entity is a data class, and his first integration test dies with a StackOverflowError. We build product-catalog-service on Spring Boot 4.1 and Kotlin 2.4.20: entities that are not data classes, Spring Data with nullable returns, validation and Jackson 3 at the REST boundary, ProblemDetail errors, transactions that roll back on checked exceptions, the Gradle build, Testcontainers 2 and virtual threads.