# sdjpa4-demo

Runnable companion project for [Spring Data JPA 3 to 4 Migration Guide](https://ankurm.com/spring-data-jpa-3-to-4-migration-guide-2/) on ankurm.com.

Four entities, two repositories, a `@NullMarked` package, seven passing behavior tests, and an A-G demo runner that prints every labelled console output shown in the article. Boots H2 in memory, so there's nothing to install beyond a JDK.

Built and verified on Eclipse Temurin JDK 21.0.11, Spring Boot 4.0.6, Spring Data JPA 4.0.6, Hibernate ORM 7.2, H2 in-memory.

## Run it

```
git clone https://ankurm.com/git.app/asmhatre/sdjpa4-demo.git
cd sdjpa4-demo
./mvnw spring-boot:run   # prints the labelled A-G demonstrations
./mvnw test               # runs the 7 behavior tests (all green)
```