DefineFetchType.java

@Entity
@Table(name = "purchaseOrder")
public class Order implements Serializable {
  
  @OneToMany(mappedBy = "order", fetch = FetchType.EAGER)
  private Set<OrderItem> items = new HashSet<OrderItem>();
  
  ...
  
}

EagerFetchingLog.log

05:01:24,504 DEBUG SQL:92 - select orderitem0_.id as id1_0_0_, orderitem0_.order_id as order_id4_0_0_, orderitem0_.product_id as product_5_0_0_, orderitem0_.quantity as quantity2_0_0_, orderitem0_.version as version3_0_0_, order1_.id as id1_2_1_, order1_.orderNumber as orderNum2_2_1_, order1_.version as version3_2_1_, product2_.id as id1_1_2_, product2_.name as name2_1_2_, product2_.price as price3_1_2_, product2_.version as version4_1_2_ from OrderItem orderitem0_ left outer join purchaseOrder order1_ on orderitem0_.order_id=order1_.id left outer join Product product2_ on orderitem0_.product_id=product2_.id where orderitem0_.id=?
05:01:24,557  INFO FetchTypes:77 - Fetched OrderItem: OrderItem , quantity: 100

LazyFetchingListLog.log

05:03:40,936 DEBUG ConcurrentStatisticsImpl:411 - HHH000117: HQL: SELECT o FROM Order o, time: 41ms, rows: 3
05:03:40,939  INFO FetchTypes:60 - Fetched all Orders
05:03:40,942 DEBUG SQL:92 - select items0_.order_id as order_id4_0_0_, items0_.id as id1_0_0_, items0_.id as id1_0_1_, items0_.order_id as order_id4_0_1_, items0_.product_id as product_5_0_1_, items0_.quantity as quantity2_0_1_, items0_.version as version3_0_1_, product1_.id as id1_1_2_, product1_.name as name2_1_2_, product1_.price as price3_1_2_, product1_.version as version4_1_2_ from OrderItem items0_ left outer join Product product1_ on items0_.product_id=product1_.id where items0_.order_id=?
05:03:40,957 DEBUG SQL:92 - select items0_.order_id as order_id4_0_0_, items0_.id as id1_0_0_, items0_.id as id1_0_1_, items0_.order_id as order_id4_0_1_, items0_.product_id as product_5_0_1_, items0_.quantity as quantity2_0_1_, items0_.version as version3_0_1_, product1_.id as id1_1_2_, product1_.name as name2_1_2_, product1_.price as price3_1_2_, product1_.version as version4_1_2_ from OrderItem items0_ left outer join Product product1_ on items0_.product_id=product1_.id where items0_.order_id=?
05:03:40,959 DEBUG SQL:92 - select items0_.order_id as order_id4_0_0_, items0_.id as id1_0_0_, items0_.id as id1_0_1_, items0_.order_id as order_id4_0_1_, items0_.product_id as product_5_0_1_, items0_.quantity as quantity2_0_1_, items0_.version as version3_0_1_, product1_.id as id1_1_2_, product1_.name as name2_1_2_, product1_.price as price3_1_2_, product1_.version as version4_1_2_ from OrderItem items0_ left outer join Product product1_ on items0_.product_id=product1_.id where items0_.order_id=?

LazyFetchingLog.log

05:03:01,504 DEBUG SQL:92 - select order0_.id as id1_2_0_, order0_.orderNumber as orderNum2_2_0_, order0_.version as version3_2_0_ from purchaseOrder order0_ where order0_.id=?
05:03:01,545  INFO FetchTypes:45 - Fetched Order: Order orderNumber: order1
05:03:01,549 DEBUG SQL:92 - select items0_.order_id as order_id4_0_0_, items0_.id as id1_0_0_, items0_.id as id1_0_1_, items0_.order_id as order_id4_0_1_, items0_.product_id as product_5_0_1_, items0_.quantity as quantity2_0_1_, items0_.version as version3_0_1_, product1_.id as id1_1_2_, product1_.name as name2_1_2_, product1_.price as price3_1_2_, product1_.version as version4_1_2_ from OrderItem items0_ left outer join Product product1_ on items0_.product_id=product1_.id where items0_.order_id=?

Order.java

@Entity
@Table(name = "purchaseOrder")
public class Order implements Serializable {
  
  @OneToMany(mappedBy = "order")
  private Set<OrderItem> items = new HashSet<OrderItem>();
  
  ...
  
}

OrderItem.java

@Entity
public class OrderItem implements Serializable
{
  
   @ManyToOne
   private Product product;
   
   ...
}

UseEagerFetching.java

OrderItem orderItem = em.find(OrderItem.class, 1L);
log.info("Fetched OrderItem: "+orderItem);
Assert.assertNotNull(orderItem.getProduct());

UseLazyFetching.java

Order newOrder = em.find(Order.class, 1L);
log.info("Fetched Order: "+newOrder);
Assert.assertEquals(2, newOrder.getItems().size());