@Entity
@Data
public class Department {

    @Id
    @GeneratedValue
    private long id;

    private String name;

    @OneToMany(mappedBy = "department")
    private List<Person> persons;

    @OneToOne
    private DepartmentType type;

    @Override
    public String toString() {
        return "Department id=" + this.id + " " + this.name;
    }

}


@Entity
@NamedQuery(name = "departmetTypes",
            query = "select dt from DepartmentType dt",
            hints = {@QueryHint(name=QueryHints.HINT_LOADGRAPH, value = "DepartmentType.withDepartments")}
)
@NamedEntityGraph(name="DepartmentType.withDepartments", attributeNodes={@NamedAttributeNode("department")})
@Data
public class DepartmentType {

    @Id
    @GeneratedValue
    private Long id;

    private String name;

    @OneToOne(mappedBy="type")
    private Department department;
}

public static void main(String[] args) {
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        EntityGraph gr = em.getEntityGraph("DepartmentType.withDepartments");
        em.createQuery("from DepartmentType", DepartmentType.class).setHint(QueryHints.HINT_LOADGRAPH, gr).getResultList().forEach(
                dt-> System.out.println(dt.getDepartment())
        );
        em.getTransaction().commit();

    }

    public static void main(String[] args) {
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        em.createNamedQuery("departmetTypes", DepartmentType.class).getResultList().forEach(
                p-> System.out.println(p.getDepartment()));
        em.getTransaction().commit();

    }

public static void main(String[] args) {
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        em.createNamedQuery("departmetTypes", DepartmentType.class)
                .setHint(QueryHints.HINT_LOADGRAPH, em.getEntityGraph("DepartmentType.withDepartments"))
                .getResultList().forEach(
                p-> System.out.println(p.getDepartment()));
        em.getTransaction().commit();

    }

@Target( { TYPE, PACKAGE })
@Retention(RUNTIME)
@Repeatable(NamedQueries.class)
public @interface NamedQuery {

   /**
    * The name of this {@code NamedQuery}.
    */
   String name();

   /**
    * The query string for this {@code NamedQuery}.
    */
   String query();

   /**
    * The flush mode for this query.
    */
   FlushModeType flushMode() default FlushModeType.PERSISTENCE_CONTEXT;

   /**
    * Whether the query (results) is cacheable or not.  Default is {@code false}, that is not cacheable.
    */
   boolean cacheable() default false;

   /**
    * If the query results are cacheable, name the query cache region to use.
    */
   String cacheRegion() default "";

   /**
    * The number of rows fetched by the JDBC Driver per trip.
    */
   int fetchSize() default -1;

   /**
    * The query timeout (in seconds).  Default is no timeout.
    */
   int timeout() default -1;

   /**
    * A comment added to the generated SQL query.  Useful when engaging with DBA.
    */
   String comment() default "";

   /**
    * The cache mode used for this query.  This refers to entities/collections returned from the query.
    */
   CacheModeType cacheMode() default CacheModeType.NORMAL;

   /**
    * Whether the results should be read-only.  Default is {@code false}.
    */
   boolean readOnly() default false;
}

@Target({TYPE})
@Retention(RUNTIME)
public @interface NamedQuery {

    /**
     * (Required) The name used to refer to the query with the {@link EntityManager}
     * methods that create query objects.
     */
    String name();

    /** (Required)
     * The query string in the Java Persistence query language.
     */
    String query();

    /**
     * (Optional) The lock mode type to use in query execution.  If a <code>lockMode</code>
     * other than <code>LockModeType.NONE</code> is specified, the query must be executed in
     * a transaction.
     * @since Java Persistence 2.0
     */
    LockModeType lockMode() default NONE;

    /** (Optional) Query properties and hints.  May include
     * vendor-specific query hints.
     */
    QueryHint[] hints() default {};
}