Getting Started with Hibernate

dependencies {
  implementation platform "org.hibernate.orm:hibernate-platform:6.4.8.Final"

  // use the versions from the platform
  implementation "org.hibernate.orm:hibernate-core"
  implementation "jakarta.transaction:jakarta.transaction-api"
}

<dependency>
    <groupId>org.hibernate.orm</groupId>
    <artifactId>hibernate-core</artifactId>
</dependency>
<dependency>
    <groupId>jakarta.transaction</groupId>
    <artifactId>jakarta.transaction-api</artifactId>
</dependency>

<dependencyManagement>
  <dependency>
    <groupId>org.hibernate.orm</groupId>
    <artifactId>hibernate-platform</artifactId>
    <version>6.4.8.Final</version>
    <type>pom</type>
    <scope>import</scope>
  </dependency>
</dependencyManagement>

# Database connection settings
hibernate.connection.url=jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1
hibernate.connection.username=sa
hibernate.connection.password=

# Echo all executed SQL to console
hibernate.show_sql=true
hibernate.format_sql=true
hibernate.highlight_sql=true

# Automatically export the schema
hibernate.hbm2ddl.auto=create

@Entity   (1)
@Table(name = "Events")   (2)
public class Event {
    ...
}

@Id   (1)
@GeneratedValue   (2)
private Long id;

private String title;

@Column(name = "eventDate")   (1)
private LocalDateTime date;

protected void setUp() {
    // A SessionFactory is set up once for an application!
    final StandardServiceRegistry registry =
            new StandardServiceRegistryBuilder()
                    .build();    (1) (2)
    try {
        sessionFactory =
                new MetadataSources(registry)             (3)
                        .addAnnotatedClass(Event.class)   (4)
                        .buildMetadata()                  (5)
                        .buildSessionFactory();           (6)
    }
    catch (Exception e) {
        // The registry would be destroyed by the SessionFactory, but we
        // had trouble building the SessionFactory so destroy it manually.
        StandardServiceRegistryBuilder.destroy(registry);
    }
}

sessionFactory.inTransaction(session -> {   (1)
    session.persist(new Event("Our very first event!", now()));   (2)
    session.persist(new Event("A follow up event", now()));
});

sessionFactory.inTransaction(session -> {
    session.createSelectionQuery("from Event", Event.class)   (1)
            .getResultList()   (2)
            .forEach(event -> out.println("Event (" + event.getDate() + ") : " + event.getTitle()));
});

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
             version="2.0">

    <persistence-unit name="org.hibernate.tutorial.jpa">   (1)
        <description>
            Persistence unit for the Jakarta Persistence tutorial of the Hibernate Getting Started Guide
        </description>

        <class>org.hibernate.tutorial.em.Event</class>     (2)

        <properties>    (3)
            <!-- Database connection settings -->
            <property name="jakarta.persistence.jdbc.url" value="jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1" />
            <property name="jakarta.persistence.jdbc.user" value="sa" />
            <property name="jakarta.persistence.jdbc.password" value="" />

            <!-- Automatically export the schema -->
            <property name="jakarta.persistence.schema-generation.database.action" value="create" />

            <!-- Echo all executed SQL to console -->
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.highlight_sql" value="true" />
       </properties>

    </persistence-unit>

</persistence>

protected void setUp() {
    entityManagerFactory = Persistence.createEntityManagerFactory("org.hibernate.tutorial.jpa");   (1)
}

void inTransaction(Consumer<EntityManager> work) {
    EntityManager entityManager = entityManagerFactory.createEntityManager();
    EntityTransaction transaction = entityManager.getTransaction();
    try {
        transaction.begin();
        work.accept(entityManager);
        transaction.commit();
    }
    catch (Exception e) {
        if (transaction.isActive()) {
            transaction.rollback();
        }
        throw e;
    }
    finally {
        entityManager.close();
    }
}

public void testBasicUsage() {
    ...
    AuditReader reader = AuditReaderFactory.get( entityManager );   (1)
    Event firstRevision = reader.find( Event.class, 2L, 1 );        (2)
    ...
    Event secondRevision = reader.find( Event.class, 2L, 2 );       (3)
    ...
}