I have an Order entity and OrderProduct. I want to show order details on frontend and of course order products in it. So how to fetch product object in OrderProduct JSON. I'm missing product object in products array. I don't need order object one more time and i think it going to be a infinite recursion stuff with it. :)
My Order entity:
#Entity
#Getter
#Setter
#Table(name ="orders")
public class Order{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
public Long id;
private BigDecimal totalPrice;
#OneToMany(mappedBy = "order", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
#JsonManagedReference(value="orders")
private List<OrderProduct> products = new ArrayList<>();
private int userId;
#DateTimeFormat(pattern="dd/MM/yyyy")
private Date date = new Date();
#DateTimeFormat(pattern="dd/MM/yyyy")
private Date deliveryDate;
#Enumerated(EnumType.STRING)
private OrderType orderType;
}
My OrderProduct entity:
#Entity
#Setter
#Getter
public class OrderProduct {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne(fetch = FetchType.EAGER)
#JsonBackReference(value="product")
#JoinColumn(name = "product_id")
private Product product;
#ManyToOne
#JsonBackReference(value="orders")
#JoinColumn(name = "order_id")
private Order order;
private Integer quantity;
}
Product entity:
#Entity
#Getter
#Setter
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(unique = true)
private String name;
private double price;
#OneToMany(mappedBy = "product", cascade = CascadeType.ALL)
#JsonManagedReference(value="ingredients")
private List<Ingredient> ingredients = new ArrayList<>();
#OneToMany(mappedBy = "product",fetch = FetchType.EAGER)
#JsonManagedReference(value="product")
private List<OrderProduct> products = new ArrayList<>();
private String fileName;
}
This can help annotate one of your entity clases with
#JsonIdentityInfo(
property = "id",
generator = ObjectIdGenerators.PropertyGenerator.class
)
Every time when JSON serialization go in circles object data will be replaced with object id or orher field of entity for your choose.
You can use #JsonViewannotation to define the fields that you need to serialize to JSON
How it works:
You need define class with interfaces. For example:
public class SomeView {
public interface id {}
public interface CoreData extends id {}
public interface FullData extends CoreData {}
}
Mark entity fields with #JsonView(<some interface.class>)
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#JsonView(SomeView.id.class)
private Long id;
#Column(nullable = false)
#JsonView(SomeView.CoreData.class)
private String username;
#Column(nullable = false)
#JsonView(SomeView.FullData.class)
private String email;
}
Annotate endpoint with #JsonView(<some interface.class>)
#GetMapping()
#JsonView(<some interface.class>)
public User getUser() {
return <get user entity somwhere>
}
In case #JsonView(SomeView.id.class) you will get this JSON:
{
id: <some id>
}
In case #JsonView(SomeView.CoreData.class):
{
id: <some id>,
username: <some username>
}
In case #JsonView(SomeView.FullData.class):
{
id: <some id>,
username: <some username>,
email: <some email>
}
#JsonView also works with embeded objects and you can annotate one field with multiply views classes - #JsonView({SomeView.FullData.class, SomeOtherView.OtherData.class})
In your case i think you should annotate all the fields you need except:
#OneToMany(mappedBy = "product",fetch = FetchType.EAGER)
#JsonManagedReference(value="product")
private List<OrderProduct> products = new ArrayList<>();
in Product
to avoid circular serialization
Or as alternative you can just use DTO classes or seralize oject to JSON manualy (https://thepracticaldeveloper.com/java-and-json-jackson-serialization-with-objectmapper/)
This can be done by my library beanknife
// This configure generate a class named ProductInfo which has the same shape with Product without property "products"
#ViewOf(value = Product.class, genName="ProductInfo", includePattern = ".*", excludes = {"products"})
class ProductInfoConfigure {}
// This configure generate a class named OrderProductRelation with the same shape of OrderProduct.
// But it has not order property and the type of its product property is change to ProductInfo generated above.
#ViewOf(value = OrderProduct.class, genName="OrderProductRelation", includePattern = ".*", excludes = {"order"})
class OrderProductRelationConfigure {
#OverrideViewProperty("product")
private ProductInfo product;
}
// This configure generate a class named OrderDetail with the same shape of Order.
// But the type of its products property is change to List<OrderProductRelation>
#ViewOf(value = Order.class, genName="OrderDetail", includePattern = ".*")
class OrderDetailConfigure {
#OverrideViewProperty("products")
private List<OrderProductRelation> products;
}
will generate these classes:
class ProductInfo {
private Long id;
private String name;
private double price;
private List<Ingredient> ingredients; // it is not processed because you have not provide the class Ingredient
private String fileName;
}
public class OrderProductRelation {
private Long id;
private ProductInfo product;
private Integer quantity;
}
public class OrderDetail {
public Long id;
private BigDecimal totalPrice;
private List<OrderProductRelation> products;
private int userId;
private Date date = new Date();
private Date deliveryDate;
private OrderType orderType;
}
Then
Order order = ...
OrderDetail orderDetail = OrderDetail.read(order);
// serialize the otherDetail instead of order.
List<Order> orders = ...
List<OrderDetail> orderDetails = OrderDetail.read(orders);
// serialize the orderDetails instead of orders.
Possible problems:
I doesn't use Lombok, so Lombok may need to be adapted because it change the byte code on the fly. But it is not a big problem, I will try to adapt it if someone commit the issue and provide enough use cases.
The generated class does not inherit the annotation on the original class. In next release I will provide a sulotion. At this moment, as a workaround, we can use custom method to convert the property manually. such as
#ViewOf(value = Order.class, genName="OrderDetail", includePattern = ".*")
class OrderDetailConfigure {
#OverrideViewProperty("products")
private List<OrderProductRelation> products;
#OverrideViewProperty("orderType")
public static String orderType(Order source) {
return source.getOrder().name();
}
}
The generated class will be changed to
public class OrderDetail {
public Long id;
private BigDecimal totalPrice;
private List<OrderProductRelation> products;
private int userId;
private Date date = new Date();
private Date deliveryDate;
private String orderType;
}
Update
Version 1.2.0 released. Add support of annotation inheritance.
#ViewOf(value = Order.class, genName="OrderDetail", includePattern = ".*")
#UseAnnotation({DateTimeFormat.class, Enumerated.class, JsonProperty.class})
class OrderDetailConfigure {
#OverrideViewProperty("products")
private List<OrderProductRelation> products;
}
generate
public class OrderDetail {
public Long id;
private BigDecimal totalPrice;
private List<OrderProductRelation> products;
private int userId;
#DateTimeFormat(pattern="dd/MM/yyyy")
private Date date;
#DateTimeFormat(pattern="dd/MM/yyyy")
private Date deliveryDate;
#Enumerated(EnumType.STRING)
private OrderType orderType;
}
Related
In my Spring Boot app, I use Hibernate and applied the necessary relations to the following entities properly.
#Entity
public class Recipe {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(nullable=false, length=50)
private String title;
#OneToMany(mappedBy = "recipe", cascade = CascadeType.ALL)
private List<RecipeIngredient> recipeIngredients = new ArrayList<>();
}
#Entity
public class RecipeIngredient {
#EmbeddedId
private RecipeIngredientId recipeIngredientId = new RecipeIngredientId();
#ManyToOne(optional = true, fetch = FetchType.LAZY)
#MapsId("recipeId")
#JoinColumn(name = "recipe_id", referencedColumnName = "id")
private Recipe recipe;
#ManyToOne(optional = true, fetch = FetchType.LAZY)
#MapsId("ingredientId")
#JoinColumn(name = "ingredient_id", referencedColumnName = "id")
private Ingredient ingredient;
}
#Entity
public class Ingredient
{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(unique=true, nullable=false, length=50)
#EqualsAndHashCode.Include
private String name;
#OneToMany(mappedBy = "ingredient", cascade = CascadeType.ALL)
private Set<RecipeIngredient> recipeIngredients = new HashSet<>();
}
Now I am trying to retrieve data by merging related entities. For example, when retrieving a Recipe, I also need to retrieve all Ingredients belonging to this Recipe.
As far as I know, I can use Projection and maybe it is better to only use Hibernate features and retrieve related table data via Java Stream. I have no idea how should I retrieve data via Hibernate.
Suppose that I just need an Optional<Recipe> that has List<Ingredient>. Then, I probably need a DTO class something like that:
#Data
public class ResponseDTO {
private Long id;
private String title;
List<RecipeIngredient> ingredients;
// getter, setter, constructor
}
So, how should I populate this DTO with the requested Recipe and corresponding Ingredient data (getting Ingredient names besides id values) using Java Stream?
Or if you suggest Projection way, I tried it but the data is multiplied by the ingredient count belonging to the searched recipe.
Update:
#Getter
#Setter
#NoArgsConstructor
public class ResponseDTO {
private Long id;
private String title;
List<IngredientDTO> ingredientDTOList;
public ResponseDTO(Recipe recipe) {
this.id = recipe.getId();
this.title = recipe.getTitle();
this.ingredientDTOList = recipe.getRecipeIngredients().stream()
.map(ri -> new IngredientDTO(ri.getIngredient().getName()))
.toList();
}
}
#Getter
#Setter
public class IngredientDTO {
private Long id;
private String name;
public IngredientDTO(String name) {
this.name = name;
}
}
First, in the ResponseDTO you will need you change the type of ingredients from List<RecipeIngredient> to List<Ingredient>.
To manually perform the mapping, you should use (to map from a suppose Recipe recipe to a RespondeDTO response):
ResponseDTO recipeToResponseDTO(Recipe recipe) {
ResponseDTO response = new ResponseDTO();
response.setId(recipe.getId());
response.setTitle(recipe.getTitle());
response.setIngredients(recipe.recipeIngredients.stream()
.map(RecipeIngredient::getIngredient()
.collect(Collectors.toList());
return response;
}
On the other hand, to model a n-n relation, I encourage you to use the approach proposed by E-Riz in the comment.
I have an entity like this and when i want to create a new product i want to post also category of id that involves this product.
is any way ta access category by id ...i try to create a constructor to category with id as param but this does not solve my problem
#Entity
#Data
#Table(name="products")
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name="name")
private String name;
#Column(name="description")
private String description;
#Column(name="base64Image")
private String base64Image;
#Column(name="price")
private Double price;
#ManyToOne(fetch = FetchType.EAGER,cascade =CascadeType.ALL)
#JoinColumn(name = "category_id")
private Category category;
#ManyToOne
#JoinColumn(name="discount_id",referencedColumnName = "id")
private Discount discount;
#OneToMany(mappedBy = "product")
private Set<ProductLocation> productLocations;
#CreationTimestamp
#Column(name="created_at")
private LocalDateTime created_at;
#UpdateTimestamp
#Column(name="updated_at")
private LocalDateTime updated_at;
}
I have this dto but when using mapstruct category id of product created remains null`
#Data
public class ProductRequestDto {
private String name;
private String description;
private String base64Image;
private Double price;
private Long categoryId;
#JsonIgnore
private Discount discount=null;
}
the mapper interface that i have used
#Mapper(componentModel = "spring")
public interface ProductMapper {
ProductMapper INSTANCE = Mappers.getMapper(ProductMapper.class);
List<ProductResponseDto> productToDto(List<Product> products);
Product dtoToProduct(ProductRequestDto product);
ProductResponseDto productToDto(Product product);
void update(#MappingTarget Product product, ProductRequestDto productDto);
}
can you suggest any solution
For me best option is to
change mapper to be abstract class instead interface adding annotation to it
#Mapper(componentModel = "spring")
adding #Mapping(target = "Category", source = "categoryId") to productToDto method
Autowiring categoryRepository to Mapper
and creating custom method for mapping from id to Entity
public Category resolveCategory(Long categoryId) {
if (categoryId == null) {
return null;
}
return categoryRepository.getById(categoryId);
}
i am new in spring boot and i could not find solution for this for a day now.
#GetMapping used to retrive item gives a responce of infinite loop of foreignkey object "user".
why am i getting this infinite loop?
how to fix it?
user object in infinite loop(the problem)
result that i want
item entity
#Entity
public class Item{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long ItemId;
#ManyToOne
#JoinColumn(name = "owner_id")
private User user;
private String ItemName;
// #Column(columnDefinition="text")
private String Description;
private double Price;
private int AvailableQuantity;
private double shippingWeight;
// #Transient
// private MultipartFile Picture;
#Enumerated(value = EnumType.STRING)
private Category category;
#OneToMany(mappedBy = "item")
#JsonIgnore
private List<CartItem> CartItemList;
}
user entity
#Entity
#Table(name = "Utilisateur")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long idU;
private String username;
private String password;
private String firstname;
private String lastname;
private String gender;
private Long phone;
private String adress;
#Temporal(TemporalType.DATE)
private Date dateofbirth;
private int rating;
private String email;
public Role role;
private Integer status;
#OneToMany(mappedBy = "user")
private List<Item> ItemList;
}
item service
#Service
public class ItemService implements ItemServiceInterface{
#Autowired
ItemRepository itemrepository;
public Optional<Item> getItemById(long id){
return itemrepository.findById(id);
}
}
item controller
#RestController
public class ItemControl {
#Autowired
ItemServiceInterface itemservice;
#GetMapping("/getitem/{id}")
public Optional<Item> getitembyid(#PathVariable Long id) {
return itemservice.getItemById(id);
}
}
You can use combination of #JsonManagedReference and #JsonBackReference to discourage Jackson from infinite serialization.
#Entity
#Table(name = "Utilisateur")
public class User {
// omitted
#JsonManagedReference
#OneToMany(mappedBy = "user", cascade = CascadeType.ALL)
private List<Item> ItemList;
}
#Entity
public class Item{
// omitted
#JsonBackReference
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "owner_id")
private User user;
}
More details could be found here https://www.baeldung.com/jackson-bidirectional-relationships-and-infinite-recursion
You can make use of lazy loading to cut the dependency loop between user and item. However, following that approach might potentially affect other parts of your projects because other codes might use the entity with an assumption that item list in user entity is already eager fetched.
A better way is not return the entity object directly to the REST response. You can define a data model for the rest response and convert the entity to that model in your service class. This way, you can completely control what to return and not to.
Another approach if you still want to use the entity as response: https://www.baeldung.com/spring-data-jpa-named-entity-graphs. This way, you can define when to use the lazy load with each specific query.
#Entity
#Table(name = "person")
public class Consignment implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(name = "person_id")
private String personId;
#Column(name = "person_name")
private String personName;
#OneToMany(fetch = FetchType.EAGER, mappedBy = "person")
#Column(name = "cars_owned")
private Set<Cars> casrsowned = new HashSet<>();
}
#Entity
#Table(name = "cars")
public class Cars implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(name = "cars_id")
private String carsId;
#ManyToOne
#JoinColumn(name = "person")
private Person person;
#OneToOne
private CarsDetail carsDetail;
}
#Entity
#Table(name = "carsDetail")
public class CarsDetail implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(name = "brand")
private String brand;
#Column(name = "color")
private String color;
#Column(name = "model")
private String model;
}
class CarModelDTO {
String personName;
List<String> models;
}
In the above relation, want to return CarModelDTO
JPA query where,
#Query("Select CarModelDTO(p.personName, p.casrsowned.carsDetail.model) from Person as p where p`enter code here`.id = :id"))
public CarModelDTO getCarmodelOwnedByAperson(#Param("id") Long id);
I tried multiple ways but it gives
org.hibernate.QueryException: illegal attempt to dereference collection
As I have already described Retrieve List from repository interface to DTO list you should go through the following step :
first create a constructor using the fields you want to be returned from the query output
in you query you should create new instance of your dto and pass the field from db to new instalnce :
so you need these changes:
1. In the constructor:
You should not use a list as List<String> models; as you should consider that your dto as a result row of DB. so you need to have a simple String model;
public CarModelDTO (String name,String model){
this.name=name;
this.model=model;
}
2. In the #Query:
you should use multi inner join appropriately
you should also append your package name to CarModelDTO in the query (here i used com.example you should change it)
#Query("Select com.example.CarModelDTO(p.personName, d.model ) from Person as p inner join p.carsowned c inner join c.carDetail d where p`enter code here`.id = :id"))
public CarModelDTO getCarmodelOwnedByAperson(#Param("id") Long id)
I've a User and Contact entities in my app and I need to every user can add some private comment about every contact and that comment must be available only for that user. So I create new entity - PrivateInfo. Here's the code.
User class:
#Entity
#Table(name = "users")
#XmlAccessorType(XmlAccessType.FIELD)
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
private String login;
// other fields
}
Contact class:
#Entity
#Table(name = "contacts")
#XmlAccessorType(XmlAccessType.FIELD)
public class Contact implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#Column(name = "first_name")
private String firstName;
#Column(name = "last_name")
private String lastName;
#OneToMany(fetch = LAZY, cascade = ALL, mappedBy = "contact")
private Set<PrivateInfo> privateInfo;
// etc.
}
PrivateInfo class:
#Entity
#Table(name = "private_info")
#XmlAccessorType(XmlAccessType.FIELD)
public class PrivateInfo implements Serializable {
#EmbeddedId
private PrivateInfoKey pk;
#Column(name = "additional_info")
private String additionalInfo;
#ManyToOne(fetch = FetchType.EAGER)
#MapsId("contactId")
private Contact contact;
}
#Embeddable
public class PrivateInfoKey implements Serializable {
#Column(name = "contact_id")
private Long contactId;
#Column(name = "user_id")
private Long userId;
}
I'm using Spring Data repositories with JpaSpecificationExecutor for querying so here's my attempt to write specification for getting all contacts with private info for specific user.
public static Specification<Contact> withPrivateInfo(final long userId) {
return new Specification<Contact>() {
#Override
public Predicate toPredicate(Root<Contact> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
Join<Contact, PrivateInfo> joinPrivateInfo = root.join(Contact_.privateInfo, JoinType.LEFT);
joinPrivateInfo.on(cb.equal(
joinPrivateInfo.get(PrivateInfo_.pk).get(PrivateInfoKey_.userId), userId
));
return cb.conjunction(); // translates in sql like '... where 1 = 1'
}
};
}
However, when I call
contactRepository.findAll(withPrivateInfo(1));
I'm receiving contacts and each of them contains in privateInfo field all users information about this contact (not only for user with id = 1, as expected). Seems like join on condition ignored.
Any suggestions how to achieve my goal? Maybe with another entities structure. Is this possible with JPA/Criteria?