JPA — How To Store java.time.YearMonth As Integer Or Date Via Hibernate Types Library

Description: Hibernate Types is a set of extra types not supported by default in Hibernate Core. One of these types is java.time.YearMonth. This is a Spring Boot application that uses Hibernate Type to store this YearMonth in a MySQL database as integer or date.

Key points:

• for Maven, add Hibernate Types as a dependency in pom.xml
• in entity use @TypeDef to map typeClass to defaultForType

Book.java

@Data
@Entity
@TypeDef(
        typeClass = YearMonthIntegerType.class, // or, YearMonthDateType
        defaultForType = YearMonth.class
)
public class Book implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String title;
    private String isbn;
    private YearMonth releaseDate;
}

BookRepository.java

@Repository
public interface BookRepository extends JpaRepository<Book, Long> {        
    Book findByTitle(String title);
}

BookStoreService.java

@RequiredArgsConstructor
@Service
public class BookstoreService {

    private final BookRepository bookRepository;

    public void newBook() {
        Book book = new Book();
        book.setIsbn("001");
        book.setTitle("Young Boy");
        book.setReleaseDate(YearMonth.now());
        bookRepository.save(book);
    }
    
    public void displayBook() {    
        Book book = bookRepository.findByTitle("Young Boy");
        System.out.println(book);
    }    
}

MainApp.java

@RequiredArgsConstructor
@SpringBootApplication
public class MainApplication {

    private final BookstoreService bookstoreService;

    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class, args);
    }

    @Bean
    public ApplicationRunner init() {
        return args -> {
            bookstoreService.newBook();
            bookstoreService.displayBook();
        };
    }
}

application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/bookstoredb?createDatabaseIfNotExist=true&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

spring.jpa.hibernate.ddl-auto=create
spring.jpa.show-sql=true

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect

spring.jpa.open-in-view=false

Console Output —

Hibernate: select book0_.id as id1_0_, book0_.isbn as isbn2_0_, book0_.release_date as release_3_0_, book0_.title as title4_0_ from book book0_ where book0_.title=?
Book(id=1, title=Young Boy, isbn=001, releaseDate=2021-06)