We Keep Coding

One-Many Relationship in Jpa

I want to get data from my entity with 1-M relationships.
Users have an entity for cv information.With JpaRepo,
Cv class :
#Entity
#Table(name = "cvs")
#Data
#AllArgsConstructor
#NoArgsConstructor
#JsonIgnoreProperties({"hibernateLazyInitializer", "handler", "educations", "works", "langueges", "technologies"})
public class CV {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
//ToDo : Employee bilgilerinin görünmesi problemi giderilecek.
#OneToOne
#JoinColumn(name = "employee_id")
private Employee employee;
#OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
List<Education> educations;
#OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
List<Work> works;
#OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
List<Languege> langueges;
#OneToMany(mappedBy = "cv", cascade = CascadeType.ALL, orphanRemoval = true)
List<Technology> technologies;
#Column(name = "github")
private String github;
#Column(name = "linkedin")
private String linkedin;
#NotNull
#NotBlank
#Column(name = "cover_letter")
private String coverLetter;
#Column(name = "photo")
private String photo;
}
This is Education class (work, languege, technology classes same):
#Data
#AllArgsConstructor
#NoArgsConstructor
#Entity
#Table(name = "cv_educations")
public class Education {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private int id;
#NotNull
#NotBlank
#Column(name = "school_name")
private String schoolName;
#NotNull
#NotBlank
#Column(name = "department")
private String department;
#NotNull
#NotBlank
#PastOrPresent
#Column(name = "starting_date")
#DateTimeFormat(pattern = "yyyy-mm-dd")
private LocalDate startingDate;
#NotBlank
#Column(name = "graduation_date")
#DateTimeFormat(pattern = "yyyy-mm-dd")
private LocalDate graduationDate;
#ManyToOne
#JoinColumn(name = "cv_id")
private CV cv;
}
I tried to build the following structure with jpa, but the constructer takes list parameter. I got an error because I couldn't write it with jpql
public interface CvRepository extends JpaRepository<CV, Integer> {
#Query("select new com.demo.humanresourcesmanagementsystem.Entities.concretes.CV" +
"(employee.firstName, employee.lastName, cv.github, cv.linkedin, cv.coverLetter," +
"educations, works, langueges, technologies)" +
"from CV cv inner join cv.employee employee inner join cv.educations educations " +
"inner join cv.works works inner join cv.langueges langueges " +
"inner join cv.technologies technologies where cv.employee.id =:employeeId")
CV findByCv(int employeeId);
}
I'd like to read about the educations, works, langueges and technologies in this entity. This means that there will be one cv as output, but there may be more than one education object within the cv (such as primary school, high school), and the incoming data will be in the following format, for example:
"firstName": "X",
"lastName" : "X",
"educations" : [
"education1" {
"school" : "x",
"department" : "x" ...},
"education2" {
"school" : "x",
"department" : "x"...}
"works" : [
"work1" {
"workplace" : "x",
"job" : "x" ...
}
]
"github" : "x",
"linkedin" : "x"
How do i set up this structure with the jpa repository? What kind of dto should I write if I'm gonna use it? Thanks.
UPDATE
When i use spring jpa derivered query (findByEmployeeId) i receive data with this format :
{
"success": true,
"message": "string",
"data": {
"id": 0,
"employee": {
"id": 0,
"email": "string",
"password": "string",
"firstName": "string",
"lastName": "string",
"nationalIdentity": "string",
"yearOfBirth": 0
},
"github": "string",
"linkedin": "string",
"coverLetter": "string",
"photo": "string"
}
}
So i cant receive data for education, work, languege and technology.

It seems you're trying to retrieve a CV by its employer.id. In that case, you can really just use the JPA query method containing keywords. In this case it would look like:
CV findByEmployeeId(int employeeId);
This should return the complete CV object as you would expect.
See here for more details on JPA query method keywords.

Why bi-directional ManyToOne causes circular dependency in Hibernate?

I have entities in my project(based on Spring-Boot + Hibernate):
#Entity
#Table(name = "user_account")
public class UserAccount {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#NotNull
#Column(name = "username")
private String userName;
#NotNull
#Column(name = "first_name")
private String firstName;
#NotNull
#Column(name = "last_name")
private String lastName;
#NotNull
#Column(name = "password")
private String password;
#CreationTimestamp
#Column(name = "birthday")
private LocalDateTime birthday;
#NotNull
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "role", referencedColumnName = "id")
private UserRole role;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "userAccount", cascade= CascadeType.ALL)
private Set<RentInfo> rents;
}
and
#Entity
#Table(name = "rent_info")
public class RentInfo {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#NotNull
#ManyToOne(cascade= CascadeType.ALL)
#JoinColumn(name="user_id")
private UserAccount userAccount;
#CreationTimestamp
#Column(name = "start_date")
private LocalDateTime startDate;
#CreationTimestamp
#Column(name = "end_date")
private LocalDateTime endDate;
#Column(name = "status")
private int status;
}
I want to create bi-directional one-to-many relation, when one user can have several rents and when we can select rents by concrete user_id, but something goes wrong
In response I get this:
{
"id": 1,
"userName": "test#mail.loc",
"firstName": "fName",
"lastName": "lName",
"password": "test",
"birthday": "2001-11-03T14:28:14",
"role": {
"name": "CLIENT"
},
"rents": [
{
"userAccount": {
"id": 1,
"userName": "test#mail.loc",
"firstName": "fName",
"lastName": "lName",
"password": "test",
"birthday": "2001-11-03T14:28:14",
"role": {
"name": "CLIENT"
},
"rents": [
{
"userAccount": {
"id": 1,
"userName": "test#mail.loc",
"firstName": "fName",
"lastName": "lName",
"password": "test",
"birthday": "2001-11-03T14:28:14",
"role": {
"name": "CLIENT"
}
.....
And this is unlimited and logically I have out of memory error. How can I fix this? what I'm doing wrong?

You have two solutions :
Use #JsonIgnore on the #ManyToOne
Do NOT serialize your entities. Use DTOs instead and take care while mapping to avoid circular dependencies

You can also use #JsonManagedReference and #JsonBackReference to solve this infinite recursion problem as follows:
#Entity
#Table(name = "user_account")
public class UserAccount {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#NotNull
#Column(name = "username")
private String userName;
#NotNull
#Column(name = "first_name")
private String firstName;
#NotNull
#Column(name = "last_name")
private String lastName;
#NotNull
#Column(name = "password")
private String password;
#CreationTimestamp
#Column(name = "birthday")
private LocalDateTime birthday;
#NotNull
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "role", referencedColumnName = "id")
private UserRole role;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "userAccount", cascade= CascadeType.ALL)
#JsonManagedReference
private Set<RentInfo> rents;
}
#Entity
#Table(name = "rent_info")
public class RentInfo {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#NotNull
#ManyToOne(cascade= CascadeType.ALL)
#JoinColumn(name="user_id")
#JsonBackReference
private UserAccount userAccount;
#CreationTimestamp
#Column(name = "start_date")
private LocalDateTime startDate;
#CreationTimestamp
#Column(name = "end_date")
private LocalDateTime endDate;
#Column(name = "status")
private int status;
}
Nevertheless, I would first map your entities to DTOs. However, you might as well need to use #JsonManagedReference and #JsonBackReference in these new DTO classes if you want all data to be available (one way to avoid this infinite recursion problem would be not mapping userAccount in RentInfoDto but you might not want that because you also want to serialize UserAccountDto data).

Update the response without null value

I have the following entities provided below,
#Entity(name = "Employee")
#Table(name = "employee")
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Employee {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#CreationTimestamp
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "creation_on" ,updatable = false)
private Date creationOn;
#Column(name = "first_name")
private String firstName;
#Column(name = "last_name")
private String lastName;
#Column(name = "email")
private String email;
#Column(name = "phoneNumber")
private String phoneNumber;
#Column(name = "age")
private Integer age;
#Column(name = "state")
#Enumerated(EnumType.STRING)
private EmployeeStates employeeState;
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "address_id", referencedColumnName = "id")
private Address address;
}
#Data
#AllArgsConstructor
#NoArgsConstructor
#Entity(name = "address")
#Table(name = "address")
public class Address {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private Long id;
#Column(name = "street")
private String street;
#Column(name = "state")
private String state;
#Column(name = "country")
private String country;
#Column(name = "zip")
private int zip;
#OneToOne(mappedBy = "address")
private Employee employee;
}
The POST call is provided below,
#PostMapping(value = "/create")
public ResponseEntity<Object> createEmployee(#Valid #RequestBody EmployeeDto employeeDto) {
try{
Employee employee = employeeService.createEmployee(employeeDto);
if(employee != null){
return new ResponseEntity<>(employee, new HttpHeaders(), HttpStatus.CREATED);
}
return new ResponseEntity<>(ApiResponseMessage.getGenericApiResponse(Boolean.FALSE, HttpStatus.UNPROCESSABLE_ENTITY,
MessageConstant.EMPLOYEE_NOT_CREATE_MSG), new HttpHeaders(), HttpStatus.UNPROCESSABLE_ENTITY);
}
catch (Exception ex) {
log.error(MessageConstant.INTERNAL_SERVER_ERROR_MSG + ex.getMessage());
return new ResponseEntity<>(ApiResponseMessage.getInternalServerError(), new HttpHeaders(), HttpStatus.INTERNAL_SERVER_ERROR);
}
}
When the response is coming, its below:
{
"id": 2,
"creationOn": "2021-02-27T15:05:23.585+00:00",
"firstName": "string",
"lastName": "string",
"email": "string",
"phoneNumber": "string",
"age": 0,
"employeeState": "ADDED",
"address": {
"id": 3,
"street": "string",
"state": "string",
"country": "string",
"zip": 0,
"employee": null
}
}
How do I not see the "employee": null in the response?

You need to use #JsonInclude(Include.NON_EMPTY) or #JsonInclude(Include.NON_NULL) on your Entity classes.
Like
#Entity(name = "Employee")
#Table(name = "employee")
#Data
#AllArgsConstructor
#NoArgsConstructor
#JsonInclude(Include.NON_EMPTY)
public class Employee {
}
#JsonInclude(Include.NON_EMPTY) -
Value that indicates that only properties with null value,or what is considered empty, are not to be included.Definition of emptiness is data type specific; see belowfor details on actual handling.
#JsonInclude(Include.NON_NULL) - Value that indicates that only properties with non-nullvalues are to be included.

I need to ignore JSON value from the child entity as below:
#OneToOne(mappedBy = "address")
#JsonIgnore
private Employee employee;
This makes all fine.

Can't save entity in hibernate

I have created simple CRUD service. With 4 entities: Customer, Provider, Product, Deal.
Customer and Provider entities has composed id AppId with the following structure:
#Getter
#Setter
#Embeddable
#NoArgsConstructor
public class AppId implements Serializable {
private String app;
private String id;
//...
}
Here is business logic I want:
Providers entity cascades and creates Product entities.
When the customer makes deal with provider I need to create entity Deal, which doesn't cascade any other entities.
It just has fields which refer to provider, customer and product of the deal.
I created some providers and customers.
Then I tried to create deal, but I got fields customer and provider null.
Here are my entities definitions:
Provider:
#Entity
#Getter
#Setter
#ToString
#NoArgsConstructor
#Table(name = "provider")
public class Provider implements Serializable {
#EmbeddedId
#Column(name = "appid")
private AppId appId;
#Column(name = "name")
private String name;
#Column(name = "firstname")
private String firstName;
#Column(name = "lastname")
private String lastName;
#Column(name = "latitude")
private float latitude;
#Column(name = "longitude")
private float longitude;
#Column(name = "work_date")
private Date workDate;
#ManyToMany(cascade = CascadeType.ALL)
#JoinTable(name = "provider_product"
, joinColumns = {
#JoinColumn(name = "provider_app"),
#JoinColumn(name = "provider_id")
}
, inverseJoinColumns = #JoinColumn(name="product_id"))
private Set<Product> products;
#OneToMany(cascade = CascadeType.ALL)
#JoinColumns({
#JoinColumn(name = "app", referencedColumnName = "app", updatable = false, insertable = false),
#JoinColumn(name = "id", referencedColumnName = "id", updatable = false, insertable = false)
})
private List<Deal> dealList = new ArrayList<>();
}
Customer:
#Entity
#Getter
#Setter
#ToString
#NoArgsConstructor
#Table(name = "customer")
public class Customer implements Serializable {
#EmbeddedId
#Column(name = "appid")
private AppId appId;
#Column(name = "firstname")
private String firstName;
#Column(name = "lastname")
private String lastName;
public Customer(AppId appId, String firstName, String lastName) {
this.appId = appId;
this.firstName = firstName;
this.lastName = lastName;
}
}
Product:
#Entity
#Getter
#Setter
#ToString
#NoArgsConstructor
#Table(name = "product")
public class Product implements Serializable {
#Id
#GeneratedValue
private long id;
#Column(name = "name")
private String name;
#Column(name = "cost")
private long cost;
}
Deal:
#Entity
#Getter
#Setter
#ToString
#NoArgsConstructor
#Table(name = "deal")
public class Deal implements Serializable {
#Id
#GeneratedValue
private long id;
#ManyToOne
#JoinColumns({
#JoinColumn(name = "provider_app", referencedColumnName = "app", insertable = false, updatable = false),
#JoinColumn(name = "provider_id", referencedColumnName = "id", insertable = false, updatable = false)
})
private Provider provider;
#ManyToOne
#JoinColumns({
#JoinColumn(name = "customer_app", insertable = false, updatable = false),
#JoinColumn(name = "customer_id", insertable = false, updatable = false)
})
private Customer customer;
#ManyToMany
#JoinTable(name = "deal_product"
, joinColumns = #JoinColumn(name="deal_id", insertable = false, updatable = false)
, inverseJoinColumns = #JoinColumn(name="product_id", insertable = false, updatable = false))
private Set<Product> product;
// deal is complete when provider entered deal id
#Column(name = "closed")
private boolean closed = false;
}

By removing insertable = false for customer and provider fields in the Deal entity, everything works fine.
{
"id": 5,
"provider": {
"appId": {
"app": "vk",
"id": "123"
},
"name": null,
"firstName": null,
"lastName": null,
"latitude": 0,
"longitude": 0,
"workDate": null,
"products": null,
"dealList": []
},
"customer": {
"appId": {
"app": "vk",
"id": "123"
},
"firstName": null,
"lastName": null
},
"product": [
{
"id": 2,
"name": "Temp",
"cost": 100
}
],
"closed": false
}
I could get the following response.
insertable = false on a field means when you are saving the entity you won't be saving the value for that field and will set the field explicitly somewhere.
insertable = true doesn't mean you will create a new Customer or Provider, that is handled by CascadeType

Spring MVC/Jackson - Nested Entity Deserialization Weirdness

I'm having a weird problem with Jackson serialization - I have a Role entity have a nested Permission entity which, in turn, contains a nested Metadata entity. When these entities are retrieved from a Spring MVC #RestController as a list, Jackson serializes the Permission collection into a JSON array. The problem is that sometimes the element placed in this array is just the id of the Permission rather than a serialized representation of the object.
Role.class:
#Entity
#Table(name = "t_db_roles")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id", scope = Role.class)
public class Role implements GrantedAuthority {
private final static Logger log = LoggerFactory.getLogger(Permission.class);
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "auto_id")
private int id;
#Column(name = "role", length = 50)
private String name;
#OneToMany(fetch = FetchType.EAGER)
#JoinTable(name = "t_db_role_permissions",
joinColumns = {#JoinColumn(name = "roleid", referencedColumnName = "auto_id")},
inverseJoinColumns = {#JoinColumn(name = "permid", referencedColumnName = "auto_id")}
)
private Set<Permission> permissions;
// getters and setters omitted
}
Permission.class:
#Entity
#Table(name = "t_db_permissions")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id", scope = Permission.class)
public class Permission implements GrantedAuthority {
private final static Logger log = LoggerFactory.getLogger(Permission.class);
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "auto_id")
private int id;
#Column(name = "name")
private String name;
#OneToOne(mappedBy = "permission")
private Metadata metadata;
}
Metadata.class
#Entity
#Table(name = "t_report_data")
#JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id", scope = Metadata.class)
public class Metadata {
#Id
#Column(name = "id", insertable = false, updatable = false)
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column(name = "file_name")
private String fileName;
#Column(name = "human_name")
private String humanName;
#Column(name = "links_to")
#JsonIgnore
private Integer linksTo;
#Column(name = "is_subreport")
#JsonIgnore
private Boolean isSubreport;
#OneToOne(cascade = javax.persistence.CascadeType.ALL, fetch = FetchType.EAGER, optional = false)
#JoinColumn(name = "permid")
private Permission permission;
}
The controller:
#RestController
public class RoleRestController {
private final static Logger log = LoggerFactory.getLogger(PermissionRestController.class);
private RoleService roleService;
private MetadataService metadataService;
#Autowired
public void setRoleService(RoleService service) {
this.roleService = service;
}
#Autowired
public void setMetadataService(ReportMetadataService service) { this.metadataService = service; }
#RequestMapping(value = "/admin/roles/", method = RequestMethod.GET)
public List<Role> getRoles() {
return roleService.getRoles();
}
}
I'm fairly sure that the problem is in serialization - echoing the List<Role> to the console works as expected, but here is the JSON returned (note the first element of the permissions array is an integer rather than a JSON object):
{
"id": 10,
"name": "ROLE_TESTER",
"permissions": [
14,
{
"id": 7,
"name": "ViewDailySettlementSummaryGL",
"metadata": {
"id": 41,
"fileName": "acct_summary_gl.rptdesign",
"humanName": "Daily Settlement Summary GL",
"permission": 7
},
"authority": "ViewDailySettlementSummaryGL"
},
{
"id": 6,
"name": "ViewDailySettlementSummary",
"metadata": {
"id": 24,
"fileName": "acct_summary_os.rptdesign",
"humanName": "Daily Settlement Summary",
"permission": 6
},
"authority": "ViewDailySettlementSummary"
}
],
"authority": "ROLE_TESTER"
}
I can work around this by handling Role serialization manually, but since the SpringMVC/Jackson serialization works for other classes in the project it seems like there must be a problem in these classes that i'm overlooking. Any ideas?