I have created Folder class (java springboot), which describes many levels folders' structure for bookmarks managing:
#Entity
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
**public class Folder** implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne(cascade = CascadeType.PERSIST)
#JoinColumn(name = "parent_id")
#JsonIdentityInfo(
generator = ObjectIdGenerators.PropertyGenerator.class,
property = "id")
private Folder parent;
#OneToMany(mappedBy = "parent", cascade = CascadeType.PERSIST)
private List<Folder> children = new ArrayList<>();
private String name;
private String path;
#OneToMany(mappedBy = "folder", cascade = CascadeType.PERSIST)
#JsonManagedReference
private List<Bookmark> bookmarkList = new ArrayList<>();
}
#Entity
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
**public class Bookmark** implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String url;
private String description;
/**
* parent folder
*/
#ManyToOne
#JsonBackReference
private Folder folder;
}
And my problem is that I can see differences in serialized JSON when loadAll() and when loadById(Long id):
#Service
#Transactional
**public class FolderService** {
private FolderRepo folderRepo;
#Autowired
public FolderService(FolderRepo folderRepo) {
this.folderRepo = folderRepo;
}
public void save(Folder folder) {
folderRepo.save(folder);
}
public List<Folder> loadAll() {
List<Folder> folderList = folderRepo.findAll();
return folderList;
}
public Folder loadById(Long id) {
Folder folder = folderRepo.findById(id).get();
return folder;
}
}
#RestController
#RequestMapping("/bookmarks-app")
**public class FolderControllerRest** {
private FolderService folderService;
#Autowired
public FolderControllerRest(FolderService folderService) {
this.folderService = folderService;
}
#GetMapping("/folders/all")
public List<Folder> getFolderListAll() {
List<Folder> folderList = folderService.loadAll();
return folderList;
}
#GetMapping("/folder/{id}")
public Folder getFolderById(
#PathVariable(name = "id") String id
) {
if (!"undefined".equals(id)) {
Long folderId = Long.parseLong(id);
return folderService.loadById(folderId);
} else return null;
}
}
Namely, the difference is ex. in folder.id=2.
When I load all using ajax:
$.ajax({
url: "/bookmarks-app/folders/all",
data: {},
method: "GET",
dataType: "JSON"
});
the parent entity is serialized to its "id" number (as I wanted),
but when use ajax:
$.ajax({
url: "/bookmarks-app/folder/2",
data: {},
method: "GET",
dataType: "JSON"
})
the parent entity is serialized to the object (screenshot below).
screenshoot
I think you are missusing #JsonIdentityInfo, the doc says
#JsonIdentityInfo allows to serialize a POJO by id when it is encountered second time during serialization.
Then in a 'list' mode you get the id, in a single mode you get the whole object.
Maybe you should Use a TypeAdaptor to get the id
Related
I want to make childComments nested in root comments. I did it. But the problem is that mention field = null in childComments but other fields are displayed correctly. However, for root comments, mention field works well.
I also want to have only two levels of comments.
Root comments -> child comments. And child comments shoul'd have childComments.
Perhaps I did not register the mapping correctly. I will be glad to hear your advice.
#Override
public CommentListResponse list(Specification<CommentEntity> spec, Pageable pageable, DeletedRecords deleted) {
pageable = DefaultSorting.apply(pageable, Sort.by(Sort.Order.desc("commentedAt")));
spec = SpecificationHelper.addDeletedFilter(spec, deleted);
Page<CommentEntity> page = commentRepository.findAll(spec, pageable);
List<CommentListResponse.CommentItem> comments = page.stream()
.filter(comment -> comment.getParentCommentId() == null)
.map(comment -> commentMapper.toListResponseItem(comment, deleted != null))
.toList();
return CommentListResponse.builder()
.data(comments)
.fromPage(page)
.build();
}
#Data
#SuperBuilder
#NoArgsConstructor
#AllArgsConstructor
#EqualsAndHashCode(callSuper = true)
public class CommentListResponse extends PagedResponse {
private List<CommentItem> data;
#Data
#Builder
#NoArgsConstructor
#AllArgsConstructor
public static class CommentItem {
private long id;
private String body;
private List<String> mentions;
private Long parentCommentId;
private List<CommentItem> childComments;
#JsonInclude(JsonInclude.Include.NON_NULL)
private Boolean deleted;
#JsonIgnore
private boolean includeDeletedField;
public Boolean getDeleted() {
return includeDeletedField ? deleted : null;
}
}
}
#Mapper(componentModel = "spring")
public interface CommentMapper {
#Mapping(source = "comment.mentionUsers", target = "mentions")
CommentListResponse.CommentItem toListResponseItem(CommentEntity comment, boolean includeDeletedField);
}
#Entity
#Table(name = "comment")
#Getter
#Setter
#Builder
#AllArgsConstructor
#NoArgsConstructor
#ToString(onlyExplicitlyIncluded = true)
public class CommentEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
#ToString.Include
private Long id;
#Column(name = "body", nullable = false)
#ToString.Include
private String body;
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name = "comment_user_mention",
joinColumns = #JoinColumn(name = "comment_id"),
inverseJoinColumns = #JoinColumn(name = "user_id"))
private List<UserEntity> mentionUsers;
#Column(name = "parent_comment_id")
#ToString.Include
private Long parentCommentId;
#OneToMany(mappedBy = "parentCommentId", fetch = FetchType.LAZY)
private List<CommentEntity> childComments;
}
JSON output: { "id": 1,
"body": "test root comment",
"mentions": ["user-1"],
"parentCommentId": null,
"childComments": [
{
"id": 3,
"body": "test child comment",
"mentions": null, - // in db i have mention for this child comment but it's null.
"parentCommentId": 1,
"childComments": [] // i don't want to see this field in child comments.
}
]
}
Thats most probably because you didn't provide a method that maps List<UserEntity> to List<String>.
Just add such a default method and test if it works.
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 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;
}
I have something similar to this:
#Entity
#Table(name = "claim", schema = "test")
public class Claim implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "idClaim", unique = true, nullable = false)
private Integer idClaim;
#OneToOne(mappedBy = "claim", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
#JsonManagedReference
private ClaimReturnInfo claimReturnInfo;
#Column(name = "notes")
private String notes;
// Getters and setters
}
#Entity
#Table(name = "claim_returninfo", schema = "test")
public class ClaimReturnInfo implements Serializable {
#Id
#Column(name = "Claim_idClaim")
private Integer id;
#MapsId("Claim_idClaim")
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "Claim_idClaim")
#JsonBackReference
private Claim claim;
#Column(name = "description")
private String description;
// Getters and setters
}
ClaimReturnInfo Id is not autogenerated because we want to propagate the Id from its parent (Claim). We are not able to do this automatically and we are getting this error: ids for this class must be manually assigned before calling save() when 'cascade' is executed in ClaimReturnInfo .
Is it possible to map Claim Id into ClaimReturnInfo Id or should we do this manually?
Even if we set this ID manually on claimReturnInfo and we can perform updates, we still get this error when trying to create a new Claim:
// POST -> claimRepository.save() -> Error
{
"notes": "Some test notes on a new claim",
"claimReturnInfo": {
"description": "Test description for a new claimReturnInfo"
}
}
In the ServiceImplemetation:
#Override
#Transactional
public Claim save(Claim claim) throws Exception {
if(null != claim.getClaimReturnInfo()) {
claim.getClaimReturnInfo().setId(claim.getIdClaim());
}
Claim claimSaved = claimRepository.save(claim);
return claimSaved;
}
I have tried using the following mappings and from your comments it was apparent that Json object is populated correctly.
I have noticed that the annotation #MapsId is the culprit.If you check the documentation of #MapsId annotation it says
Blockquote
The name of the attribute within the composite key
* to which the relationship attribute corresponds. If not
* supplied, the relationship maps the entity's primary
* key
Blockquote
If you change #MapsId("Claim_idClaim") to #MapsId it will start persisting your entities.
import javax.persistence.*;
#Entity
#Table(name = "CLAIM")
public class Claim {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "idClaim", unique = true, nullable = false)
private Long idClaim;
#Column(name = "notes")
private String notes;
#OneToOne(mappedBy = "claim", cascade = CascadeType.ALL, optional = false)
private ClaimReturnInfo claimReturnInfo;
public Long getIdClaim() {
return idClaim;
}
public String getNotes() {
return notes;
}
public void setNotes(String notes) {
this.notes = notes;
}
public ClaimReturnInfo getClaimReturnInfo() {
return claimReturnInfo;
}
public void setClaimReturnInfo(ClaimReturnInfo claimReturnInfo) {
if (claimReturnInfo == null) {
if (this.claimReturnInfo != null) {
this.claimReturnInfo.setClaim(null);
}
} else {
claimReturnInfo.setClaim(this);
}
this.claimReturnInfo = claimReturnInfo;
}
}
package com.hiber.hiberelations;
import javax.persistence.*;
#Entity
#Table(name = "CLAIM_RETURN_INFO")
public class ClaimReturnInfo {
#Id
#Column(name = "Claim_idClaim")
private Long childId;
#Column(name = "DESCRIPTION")
private String description;
#MapsId
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "Claim_idClaim")
private Claim claim;
public Long getChildId() {
return childId;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Claim getClaim() {
return this.claim;
}
public void setClaim(Claim claim) {
this.claim = claim;
}
}
I have a table master table user ,topics table and comments table
where in for a single topic there can be multiple comments
user table will be already populated.
I will get a post request to save the topic with structure like below
{
"topicId":"T001",
"title":"stackoverflow",
"commentBeans":[
{
"comment":"developer platform"
},
{
"comment":"developer communtiy"
}
]
}
Frameworks used:
spring boot
JPA
DB : postgressql
I am able to save the data the traditional way (i.e get the request and save topic bean first. get the primarykey from saved entity and loop the list of commentbean where user num will be set dynamically by another get service and save them)
I wanted to know if there is anyway to save the data with single save query.
#Entity
#Table(name ="user")
public class User implements Serializable {
#Id
#Column(name = "user_num")
#GeneratedValue(strategy = GenerationType.AUTO)
private Long userNum;
#Column(name = "user_id")
private String userId;
#Column(name = "username")
private String userName;
}
#Entity
#Table(name = "topics")
public class TopicBean implements Serializable {
#Id
#Column(name = "topic_num")
#GeneratedValue(strategy = GenerationType.AUTO)
private Long topicNum;
#Column(name = "topicId")
private String topicId;
#Column(name = "title")
private String title;
#OneToMany(mappedBy="topicBean")
private List<CommentBean> commentBeans;
}
#Entity
#Table(name = "comments")
public class CommentBean implements Serializable {
#EmbeddedId
private CommentBeanKey key;
#Column(name = "comment")
private string comment;
#ManyToOne
#JoinColumn(name="topic_num")
private TopicBean topicBean;
#ManyToOne
#JoinColumn(name="user_num")
private TopicBean topicBean;
}
#Embeddable
public class CommentBeanKey implements Serializable{
private static final long serialVersionUID = 5889249943605061539L;
#Column(name ="topic_num")
private Long topicNum;
#Column(name ="user_num")
private Long userNum;
}
I saw the below link and am little worried if am doing the wrong way. any help is appreciated.
https://thoughts-on-java.org/hibernate-tips-how-to-map-an-entity-to-multiple-tables/
Parent.java
#Entity
#Table(name = "parent")
#Getter
#Setter
#AllArgsConstructor
#NoArgsConstructor
#ToString
public class Parent {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int parentId;
private String name;
#OneToMany(mappedBy="parent",fetch=FetchType.LAZY,cascade = CascadeType.PERSIST)
private List<Child> child = new ArrayList<Child>();
}
Child.java
#Entity
#Table(name = "child")
#Getter
#Setter
#AllArgsConstructor
#NoArgsConstructor
#ToString
public class Child {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int childId;
private String account;
#ManyToOne(fetch = FetchType.LAZY, targetEntity = Parent.class)
#JoinColumn(name="parentId", referencedColumnName = "parentId", nullable = false)
private Parent parent;
}
Controller.java
//save Child with Parent at same
#PostMapping(value = "/onetomany")
public String OneToMany(#RequestBody Parent parent)
{
System.out.println("Parent: "+parent.toString());
for (Child child : parent.getChild()) {
child.setParent(parent);
}
parent.setChild(parent.getChild());
parentRepository.save(parent);
return "saved";
/*{
"name":"Romil",
"child":[
{"account":"1"},
{"account":"2"}
]
}*/
}
//save Child with Parent's ID
#PostMapping(value = "/onetomanyPID")
public String OneToMany(#RequestBody Child child)
{
child.setParent(child.getParent());
childRepository.save(child);
return "saved";
/*{
"account":"3",
"parent":{
"parentId":"1",
"name":"Romil"
}
}*/
}