For my spring boot application, I have below dto class
RoomDto
#Data
#FieldDefaults(level = AccessLevel.PRIVATE)
public class RoomDto {
Long id;
String title;
Long roomSize;
LocalDateTime createdOn;
#JsonManagedReference("favoriteRoom")
#ToString.Exclude
Set<FavoriteDto> favorites;
//#JsonManagedReference("animalRoom")
#ToString.Exclude
#JsonIgnore
Set<AnimalDto> animals;
}
AnimalDto
#Data
#FieldDefaults(level = AccessLevel.PRIVATE)
#NoArgsConstructor
#AllArgsConstructor
public class AnimalDto {
Long id;
String title;
LocalDateTime located;
String type;
Long preference;
#JsonManagedReference("animalFavoriteRoom")
#ToString.Exclude
Set<FavoriteDto> favoriteRooms;
//#JsonBackReference("animalRoom")
RoomDto roomDto;
}
so basically one room can have multiple Animals (ManyToOne relationship) but when I try to find an animals list from the given room I do not get animals data for that room.
{
"id": 1,
"title": "Green",
"roomSize": 20,
"createdOn": null,
"favorites": [
{
"id": 1
}
]
}
and below is my service class implementation.
public RoomDto getRoomDetails(Long id, String parameter, String by) {
Room room = roomRepository.findById(id).get();
List<Animal> animals = animalRepository.findByRoom(room, Sort.by(Sort.Direction.fromString(by),parameter));
room.setAnimals(new HashSet<>(animals));
return mapper.roomToRoomDto(room);
}
I do see my animal's list retrieved from db but not appearing in UI, I assume it is due to #JsonIgnore it is suppresing it, is it correct? if yes how can I do work around?
Related
I have two simple classes Student and Course. I am trying to set up many to many relationship between these classes. I want to use additional table whose PRIMARY KEY is the combination of the primary keys of student and course tables (student_id and course_id).
The student class:
#Entity
#Table(name = "student")
#Getter
#Setter
#AllArgsConstructor
#NoArgsConstructor
public class Student {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(name = "name")
private String name;
#Column(name = "surname")
private String surname;
#OneToMany(mappedBy = "student")
private Set<CourseStudent> courses;
}
The course class:
#Entity
#Table(name = "course")
public class Course {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String courseName;
#OneToMany(mappedBy = "course")
Set<CourseStudent> students;
}
The entity that stores the relationship between course and the student:
#Entity
#NoArgsConstructor
#Data
public class CourseStudent {
#EmbeddedId
CourseStudentKey id;
#ManyToOne
#MapsId("studentId")
#JoinColumn(name = "student_id")
Student student;
#ManyToOne
#MapsId("courseId")
#JoinColumn(name = "course_id")
Course course;
public CourseStudent(Student student, Course course) {
this.student = student;
this.course = course;
this.rating = 0;
}
int rating;
}
Attention: Since I want to have additional features in this entity (for example, storing the rating of the students for courses), I don't want to use #JoinTable idea that we implement in the Student class.
Since I have multiple attributes in the primary key of CourseStudent entity, I used the following class
#Embeddable
#Data
public class CourseStudentKey implements Serializable {
#Column(name = "student_id")
Long studentId;
#Column(name = "course_id")
Long courseId;
}
I have the following POST request to insert the student into a course:
#PostMapping("/insert/students/{studentId}/courses/{courseId}")
public CourseStudent insertStudentIntoCourse(#PathVariable(value = "studentId") Long studentId,
#PathVariable(value = "courseId") Long courseId) {
if (!studentRepository.existsById(studentId)) {
throw new ResourceNotFoundException("Student id " + studentId + " not found");
}
if (!courseRepository.existsById(courseId)) {
throw new ResourceNotFoundException("Course id " + courseId + " not found");
}
CourseStudent courseStudent = new CourseStudent(
studentRepository.findById(studentId).get(),
courseRepository.findById(courseId).get()
);
return courseStudentRepository.save(courseStudent);
}
I have manually added Student and the Course into my local database and send this request by using Postman.
http://localhost:8080/insert/students/1/courses/1
However, I get the following error:
{
"timestamp": "2022-08-04T12:33:18.547+00:00",
"status": 500,
"error": "Internal Server Error",
"path": "/insert/students/1/courses/1"
}
In the console, I get NullPointerException. What is the thing I am doing wrong here?
this is my order entity,
#Data
#NoArgsConstructor
#AllArgsConstructor
#ToString
#Entity
#Table(name = "ordertab")
public class Order {
#Id
private int orderId;
private String orderDate;
#ManyToMany(targetEntity = Medicine.class,cascade = CascadeType.ALL)
#JoinTable(name="ord_med",
joinColumns = {#JoinColumn(name="ord_id")},
inverseJoinColumns = {#JoinColumn(name="med_id")})
private List<Medicine> medicineList;
private String dispatchDate;
private float totalCost;
#ManyToOne(targetEntity = Customer.class,cascade = CascadeType.ALL)
#JoinColumn(name= "custord_fk",referencedColumnName = "customerId")
private Customer customer;
private String status;
}
and this is my medicine entity,
#Data
#NoArgsConstructor
#AllArgsConstructor
#ToString
#Entity
public class Medicine {
#Id
private String medicineId;
private String medicineName;
private float medicineCost;
private LocalDate mfd;
private LocalDate expiryDate;
**#ManyToMany(cascade = CascadeType.ALL, mappedBy = "medicineList")
private List<Order> orderList;** //order/ medicine many to many mapping
// OneToOne Mapping
#OneToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "categoryId", referencedColumnName = "categoryId")
private Category category;
in my order service interface i have a method,
List showAllOrder(string medId);
I have to fetch all orders that has the matching med id.
this many to many mapping have created a additional table ord_med with two columns named ord_id,med_id(type foreign keys).In addition to that due to this bidirectional mapping(i believe it is) while creating object of medicine entity its asking me to add orderlist ,how to approach this method or how exactly should i solve this. thankyou.
in your OrderRepository you can implements this method
findByMedicineId(String id);
if i go for findByMedicineId(String id);
it gives error saying no property medicineId is found in Order entity,cuz the property medicineId is in Medicine entity,while defining custom method in repository follows rules, refer https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#jpa.query-methods.query-creation
anyway I have found the solution for this,
public List<Order> getOrderListBasedOnMedicineId(String medicineid) {
Optional<Medicine> med=medicineRepo.findById(medicineid);//find if medicine is present in database with the id.
if(med.isEmpty()) {
return null;
}
List<Order> orders = medicineServ.getOrderList(); //getorderlist defined in service implementation of medicine.
List<Order> ordersWithMedId = new ArrayList();//new list to add all orders that has atleast one medicineId that matches.
for(int i=0;i<orders.size();i++) {
List<Medicine> medicines= orders.get(i).getMedicineList();
for(int j=0;j<medicines.size();j++) {
ordersWithMedId.add(orders.get(i));
}
}
return ordersWithMedId;//returning the list of orders.
}
#Override
public List<Order> getOrderList() {//medicine service implementation
return orderRepo.findAll();
}
//OrderController
#GetMapping("/orders/list/{id}")
public ResponseEntity<List<Order>> getOrderListBasedOnMedicineId(#PathVariable("id") String id) {
List<Order> ord= orderService.getOrderListBasedOnMedicineId(id);
if(ord==null) {
throw new OrderNotFoundException("Order not found with medicine id:"+id);
}
return new ResponseEntity<List<Order>>(orderService.getOrderListBasedOnMedicineId(id),HttpStatus.OK);
}
I have Student entity and Course entity. This is #ManyToOne relationship i.e. Student may attend only one course at a time, but courses may have multiple students.
#Entity
public class Student {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String studentId;
private String firstName;
private String secondName;
#ManyToOne
#JoinColumn(name = "course_id")
//#JsonIgnore
private Course course;
#Entity
public class Course {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String courseName;
#OneToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, mappedBy = "course", orphanRemoval = true, targetEntity = Student.class)
private List<Student> students = new ArrayList<>();
I post my data with the following json:
{
"id": 1,
"courseName": "course134",
"students" : [
{
"id" : 1,
"studentId": "123",
"firstName": "John1",
"secondName": "Name1"
},
{
"id" : 2,
"studentId": "1234567",
"firstName": "John2",
"secondName": "Name2"
}
then, as I get courses I receive:
{
"id": 1,
"courseName": "course134",
"students": []
}
How to list Students attending specific course?
I made up a Query in StudentRepository
#Query("SELECT s from Student s where s.id = :courseName")
Optional<Student> getStudentByCourseName(String courseName);
Still not working.
this is my Repository code:
#Repository
public interface CourseRepository extends JpaRepository<Course, Long> {
Optional<Course> findCourseByCourseName(String courseName);
#Query("SELECT c.students FROM Course c WHERE c.courseName = :courseName")
Optional<Student> getStudentsByCourseName(String courseName);
}
this is my Service method
public Optional<Student> findStudentByCourse(String courseName){
return courseRepository.getStudentsByCourseName(courseName);
}
and finally my Controller:
#GetMapping("/student/course/{courseName}")
public ResponseEntity<Student> findCoursesWithStudentId(#PathVariable String courseName) {
Optional<Student> byCourseName = studentService.findStudentByCourse(courseName);
if (byCourseName.isPresent()) {
return ResponseEntity.ok(byCourseName.get());
} else {
return ResponseEntity.notFound().build();
}
}
You should query the Course table, not the Student table. Also, the query will return the list, not just one entity, so change your method's return type also...
#Query("SELECT c.students FROM Course c WHERE c.courseName = :courseName")
List<Student> getStudentsByCourseName(String courseName) {}
edit
You can always do it like so:
Excute the simple method:
Course findByCourseName(String courseName) {}
and then just get its Students by a simple:
course.getStudents();
We have an Entity called Customers that has a OneToOne relationship to the Entity Address.
The Customer's PK should be manually defined. The Address' PK should be automatically defined.
So, in Customer I omitted the #GeneratedValue and I'm providing is value manually. But, when trying to save I'm getting the following error:
2018-11-07 10:42:17.810 ERROR 1257 --- [nio-8080-exec-2] o.h.i.ExceptionMapperStandardImpl : HHH000346: Error during managed flush [Validation failed for classes [br.com.customers.entity.Address] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
ConstraintViolationImpl{interpolatedMessage='não pode ser nulo', propertyPath=street, rootBeanClass=class br.com.customers.entity.Address, messageTemplate='{javax.validation.constraints.NotNull.message}'}
The problem is that the address.street is being provided and I can't realize why JPA is complaining that it's null...
Here are the JSON body that I'm trying to save. (It's being deserialized correctly, as, Address is not NULL)
{
"customer_Id": 50,
"name": "name",
"company_name": "company_name",
"email": "email#provider.com",
"business_phone": "(00) 1111-2222",
"mobile_phone": "(00) 1111-2222",
"document": "123456789",
"state_registration_number": "ISENTO",
"state_registration_type": "NO_CONTRIBUTOR",
"city_registration_number": "ISENTO",
"classification": "AUTO",
"address": {
"street": "STREET NAME",
"number": "NUMBER",
"complement": "COMPLEMENT",
"zip_code": "ZIP_CODE",
"neighborhood": "NEIGHBORHOOD",
"city": "CITY",
"state": "STATE"
}
}
Here are the Customer Entity:
#Data
#Entity(name = "X_CUSTOMERS")
public class Customer {
#Id
private int customer_Id;
#NotNull
private String name;
private String company_name;
private String email;
private String business_phone;
private String mobile_phone;
#NotNull
private String document;
private String state_registration_number;
private String state_registration_type;
private String city_registration_number;
#NotNull
private String classification;
#OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST)
#JoinColumn(name = "address_id")
private Address address;
}
And here, Address Entity:
#Data
#Entity(name = "X_ADDRESS")
public class Address {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int address_Id;
#NotNull
private String street;
private String number;
private String complement;
private String zip_code;
private String neighborhood;
private String city;
private String state;
}
What Am I doing wrong?
Thanks!!!
Adding the code do persist the entities:
Customer Repository:
public interface CustomerRepository extends JpaRepository<Customer, Integer> {
}
To persist:
#RestController
#RequestMapping("/customers")
public class CustomersController {
private CustomerRepository customerRepository;
public CustomersController(CustomerRepository customerRepository) {
this.customerRepository = customerRepository;
}
#PostMapping
public Customer postCustomer(#RequestBody Customer customer) {
return customerRepository.save(customer);
}
}
From reading the Hibernate documentation, the save operation only persist entities with auto generated ids. So, if you intend to set the id yourself, then what you need, is to change your insert method for persist. And since you customer has an id that is not auto generated, maybe this could be the issue. You can read more in this blog.
#PostMapping
public Customer postCustomer(#RequestBody Customer customer) {
return customerRepository.persist(customer);
}
Hope it helps.
If you add CascadeType.MERGE, it will work
#OneToOne(fetch = FetchType.EAGER, cascade = { CascadeType.PERSIST, CascadeType.MERGE})
#JoinColumn(name = "address_id")
private Address address;
you set the customer id(50) so the following line of SimpleJpaRepository will be executed.
return this.em.merge(entity);
I have a JPA entity Person and an entity Team. Both are joined by an entity PersonToTeam. This joining entity holds a many-to-one relation to Person and one to Team. It has a multi-column key consisting of the ids of the Person and the Team, which is represented by an #EmbeddedId. To convert the embedded id back and forth to the request id I have a converter. All this follows the suggestion on Spring Data REST #Idclass not recognized
The code looks like this:
#Entity
public class PersonToTeam {
#EmbeddedId
#Getter
#Setter
private PersonToTeamId id = new PersonToTeamId();
#ManyToOne
#Getter
#Setter
#JoinColumn(name = "person_id", insertable=false, updatable=false)
private Person person;
#ManyToOne
#Getter
#Setter
#JoinColumn(name = "team_id", insertable=false, updatable=false)
private Team team;
#Getter
#Setter
#Enumerated(EnumType.STRING)
private RoleInTeam role;
public enum RoleInTeam {
ADMIN, MEMBER
}
}
#EqualsAndHashCode
#Embeddable
public class PersonToTeamId implements Serializable {
private static final long serialVersionUID = -8450195271351341722L;
#Getter
#Setter
#Column(name = "person_id")
private String personId;
#Getter
#Setter
#Column(name = "team_id")
private String teamId;
}
#Component
public class PersonToTeamIdConverter implements BackendIdConverter {
#Override
public boolean supports(Class<?> delimiter) {
return delimiter.equals(PersonToTeam.class);
}
#Override
public Serializable fromRequestId(String id, Class<?> entityType) {
if (id != null) {
PersonToTeamId ptid = new PersonToTeamId();
String[] idParts = id.split("-");
ptid.setPersonId(idParts[0]);
ptid.setTeamId(idParts[1]);
return ptid;
}
return BackendIdConverter.DefaultIdConverter.INSTANCE.fromRequestId(id, entityType);
}
#Override
public String toRequestId(Serializable id, Class<?> entityType) {
if (id instanceof PersonToTeamId) {
PersonToTeamId ptid = (PersonToTeamId) id;
return String.format("%s-%s", ptid.getPersonId(), ptid.getTeamId());
}
return BackendIdConverter.DefaultIdConverter.INSTANCE.toRequestId(id, entityType);
}
}
The problem with this converter is, that the fromRequestId method gets a null as id parameter, when a post request tries to create a new personToTeam association. But there is no other information about the payload of the post. So how should an id with foreign keys to the person and the team be created then? And as a more general question: What is the right approach for dealing many-to-many associations in spring data rest?
After running into the same issue I found a solution. Your code should be fine, except I return new PersonToTeamId() instead of the DefaultIdConverter if id is null in fromRequestId().
Assuming you are using JSON in your post request you have to wrap personId and teamId in an id object:
{
"id": {
"personId": "foo",
"teamId": "bar"
},
...
}
And in cases where a part of the #EmbeddedId is not a simple data type but a foreign key:
{
"id": {
"stringId": "foo",
"foreignKeyId": "http://localhost:8080/path/to/other/resource/1"
},
...
}