I would like to apologize in advanced if this is a duplicate, however, I've been looking around for the last 2 days and have not found anything that solves my problem.
I have created a web service to which I would like to POST a JSON object. My issue is the following:
Let's say I have three objects.
ObjectA:{
"name":"",
"address":"",
"id":""
}
ObjectB:{
"id:"",
"name":"",
"objectA":{ [ObjectA]}
}
ObjectC:{
"id:"",
"name":"",
"objectA":{},
"objectB":{}
}
As you can see,ObjectC references ObjectA and ObjectB, which also references ObjectA. When inserting a new ObjectC, ObjectC.objectA should be the same as ObjectC.objectB.objectA.
The POST is consumed by the following method:
#POST
#Override
#Consumes({"application/xml", "application/json"})
public void create(ObjectC entity) {
super.create(entity);
}
The classes look like this: (plus the getters and setters)
#Entity
#Table(name = "object_a")
public class ObjectA{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id")
private Integer id;
#NotNull
#Column(name = "u_name")
private String uName;
#Column(name = "address")
private String address;
}
#Entity
#Table(name = "object_b")
public class ObjectB{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id")
private Integer id;
#Column(name = "name")
private String name;
#JoinColumn(name = "object_a", referencedColumnName = "id")
#ManyToOne(optional = false, cascade = CascadeType.PERSIST)
#Valid
private ObjectA objectA;
}
#Entity
#Table(name = "object_c")
public class ObjectC{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id")
private Integer id;
#Column(name = "name")
private String name;
#JoinColumn(name = "object_a", referencedColumnName = "id")
#ManyToOne(optional = false, cascade = CascadeType.PERSIST)
#Valid
private ObjectA objectA;
#JoinColumn(name = "object_b", referencedColumnName = "id")
#ManyToOne(optional = false, cascade = CascadeType.PERSIST)
#Valid
private ObjectB objectB;
}
Note: I am able to POST an ObjectA, and an ObjectB without any problem.
PROBLEM
The problem is that ObjectC.objectA and ObjectC.objectB.objectA are being inserted (or attempted to) as different values, which in throws an exception because ObjectA.uName is unique. If this wasn't the case, two new ObjectA's would have been created.
I was able to solve this problem in Hibernate, by doing something like the following:
ObjectA a = new ObjectA();
ObjectB b = new ObjectB();
ObjectC c = new ObjectC();
b.setObjectA(a);
c.setObjectA(a);
c.setObjectB(b);
session.beginTransaction();
session.save(a);
session.save(b);
session.save(c);
session.getTransaction().commit();
How can I go about this?
For anyone out there who might come across this issue, I have found the solution.
I did it in a very similar way to what I did in hibernate (see above).
I edited the create method I posted above, to this:
#POST
#Override
#Consumes({"application/xml", "application/json"})
public void create(ObjectC entity) {
if(entity.getObjectA().getId()==null){//If objectA doesn't have an ID, it must be new
entity.getObjectB().setObjectA(entity.getObjectA());
em.persist(entity.getObjectA());
em.persist(entity.getObjectB());
em.persist(entity);
}else{//Otherwise, everything may be inserted at once.
super.create(entity);
}
}
By the way, the super.create(entity) method contains the following:
public void create(T entity){
getEntityManager().persist(entity);
}
Related
I have a spring boot application with two entities in a relationship. MeetingSetting and MeetingTime meetingSetting can have unlimited meetingTimes. So far the databases are generating without problem, but When I try to save my Entity they are saved but different from each other, they are saved independently. Meaning MeetingName which is a foreign key inside MeetingTime is not saved but seen as null (I debugged and tried finding out why but could not find anything) THe other values are saved-
could someone point me out what my error is?
this is the json I am sending:
{
"meetingName":"TEst",
"meetingPw":"",
"meetingTime":[
{
"date":"2021-05-31",
"startTime":"15:30",
"endTime":"16:30"
},
{
"date":"2021-06-21",
"startTime":"15:30",
"endTime":"17:30"
},
{
"date":"2021-06-21",
"startTime":"11:01",
"endTime":"11:01"
}
]
}
MeetingSettings:
#Entity
#Table(name = "meeting_settings")
#Data
public class MeetingsSetting {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "meeting_name", unique = true)
private String meetingName;
#Column(name = "meeting_url")
private String meetingUrl;
#Column(name = "meeting_pw")
private String meetingPw;
#OneToMany(mappedBy = "meeting_Name", cascade = CascadeType.ALL)
private Set<MeetingTime> meetingTime = new HashSet<>();
}
MeetingTime:
#Entity
#Table(name = "meeting_times")
#Data
public class MeetingTime {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "meeting_date")
private String date;
#Column(name = "start_time")
private String startTime;
#Column(name = "end_time")
private String endTime;
#ManyToOne
#JoinColumn(name = "meeting_name" ,insertable = false, updatable = false , referencedColumnName = "meeting_name")
private MeetingsSetting meeting_Name;
}
this is how I try to save the entity:
#RestController
#RequestMapping("/api/meetingSetting")
public class MeetingSettingController {
#Autowired
MeetingSettingService meetingSettingService;
#PostMapping("/")
public void saveMeeting(#RequestBody MeetingsSetting meetingsSetting){
meetingSettingService.saveMeeting(meetingsSetting);
}
}
My service calls the save method of an jpaRepository.
In a bi-directional One to Many, you have to synchronize both sides of the association.
You can simply iterate over all MeetingTime objects and set the corresponding MeetingSetting to it.
Your MeetingSettingService's saveMeeting method could do this:
public void saveMeeting(MeetingsSetting meetingsSetting) {
// ...
// here you're synchronizing both sides of the association
meetingsSetting.getMeetingTime()
.forEach(mt -> mt.setMeetingSetting(meetingSetting));
// ...
repository.save(meetingSetting);
}
Solution to my question, I am not sure if this is a good or correct way of solving this maybe someone can advice me a better solution:
#Entity
#Table(name = "meeting_times")
#Data
public class MeetingTime implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "meeting_date")
private String date;
#Column(name = "start_time")
private String startTime;
#Column(name = "meeting_name")
private String meeting_name;
THIS IS THE PART WHICH IS CALLED FROM THE METHOD INSIDE MEETINGSCONTROLLER
#Column(name = "end_time")
private String endTime;
#ManyToOne
#JoinColumn(name = "meeting_name" ,insertable = false, updatable = false, referencedColumnName = "meeting_name")
private MeetingsSetting meetingName;
}
MeetingsTime Entity:
#RestController
#RequestMapping("/api/meetingSetting")
public class MeetingSettingController {
#Autowired
MeetingSettingService meetingSettingService;
#PostMapping("/")
public void saveMeeting(#RequestBody MeetingsSetting meetingsSetting){
meetingsSetting.getMeetingTime()
.forEach(mt -> mt.setMeeting_name(meetingsSetting.getMeetingName()));
// ...
meetingSettingService.saveMeeting(meetingsSetting);
}
}
I am kinda beginner when it comes to hibernate, but i have been dealing with a problem for several hours, and i need your help.
I have an application that manages articles, and each article is written by an author.
What i want to do is to add an article to a database, with its author_id field being null, and only after that to update that field.
However, hibernate refuses to update my entity in the database.
public <Article> void updateElement(Article entity) {
EntityManager entityManager = createEntityManager();
try {
entityManager.getTransaction();
entityManager.merge(entity);
entityManager.getTransaction().commit();
}
catch(RuntimeException e ){
entityManager.getTransaction().rollback();
}
finally {
entityManager.close();
}
}
This is how i try to update the entry. I receive an Article as a parameter, for which i know for sure that it is in the database. And after that i try to do merge in order to update it. But i don't know if it the right approach. Please help me.
The article class:
#ToString
#AllArgsConstructor
#NoArgsConstructor
#Setter
#Getter
#Entity
#Table( name = "Article")
public class Article {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "article_id")
private Integer id;
#NotBlank
#Column(name = "title")
private String title;
#NotBlank
#Column(name = "publication_date")
private Date publicationDate;
#ManyToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY)
#JoinColumn(name = "author_id")
private Author author;
#ManyToMany(fetch = FetchType.EAGER)
#Enumerated(EnumType.STRING)
#JoinTable(name = "article_tags",
joinColumns = #JoinColumn(name = "article_id"),
inverseJoinColumns = #JoinColumn(name ="tag_id"))
private Set<Tag> tags = new HashSet<>();
}
and the author class
#NoArgsConstructor
#Setter
#Getter
#Entity
#Table(name = "Authors")
public class Author {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE,
generator = "entity_id_seq")
#Column(name = "author_id",updatable = false)
private int id;
#NotBlank
#Column(name = "author_name")
private String name;
#OneToMany(mappedBy = "author",cascade = CascadeType.ALL,fetch = FetchType.LAZY)
private Set<Article> writtenArticles = new HashSet<>();
}```
please begin your transaction and not only get the transaction:
replace the
entityManager.getTransaction();
by
entityManager.getTransaction().begin();
I have two objects. The company that can have multiple nested addresses.
#Entity
#Data
#Table(name = "company")
public class Company {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#Column(name = "phone")
private String phone;
#OneToMany(mappedBy = "company", cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.LAZY)
private List<Address> addresses;
}
Address class looks like this:
#Data
#Entity
#Table(name = "address")
#ToString(exclude = "company")
public class Address {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private Long id;
#Column(name = "postal_code")
private String postalCode;
#Column(name = "city")
private String city;
#Column(name = "street")
private String street;
#JsonIgnore
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "company_id")
private Company company;
}
I want somehow if it's possible, make a dynamic query that searches through the nested collection property. I made a search method which uses example matcher but the result is wrong. Every time I got everything from DB, not only company with address postal code that I'm looking for.
My search method looks like this:
#PostMapping("/search")
public List<Company> search(#RequestBody final Company company){
return companyRepository.findAll(Example.of(company,
ExampleMatcher.matchingAny()
.withIgnoreNullValues()
.withIgnorePaths("id")
.withStringMatcher(ExampleMatcher.StringMatcher.STARTING)));
}
In my database, I have two objects and this is the result of the search:
As you can see I received everything from DB instead of the only first company which address postal code starts with 1.
Hi you can use Specification<T>
https://spring.io/blog/2011/04/26/advanced-spring-data-jpa-specifications-and-querydsl/
For this you need to extend from interface JpaSpecificationExecutor:
public interface UserRepository extends JpaRepository<User> ,JpaSpecificationExecutor<User>{
}
And you also need to implement your custom Specification<T>
And then you can use repository.findAll(your impleneted Specification);
Spring docs :
https://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/JpaSpecificationExecutor.html
I think this is helpful.
I have a User Class
#Entity(name = "users")
#Table(name = "users")
public class User implements UserDetails {
static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "user_id", nullable = false)
private Long id;
#Column(name = "username", nullable = false, unique = true)
private String username;
#Column(name = "password", nullable = false)
private String password;
}
Tied to a simple Repository
public interface UserRepository extends PagingAndSortingRepository<User, Long> {
}
And I have an Instructor Class that has a nested User object
#Entity
#Table(name = "instructors")
public class Instructor {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "instructor_id", nullable = false, updatable = false)
private Long id;
#OneToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "user_id")
private User user;
#OneToMany(fetch = FetchType.EAGER)
#JoinColumn(name = "course_id")
private List<Course> courses;
}
It is saved with the following repository
public interface InstructorRepository extends PagingAndSortingRepository<Instructor, Long> {
}
The JSON I am posting
{
"user": {
"id": 1
}
}
When I try to do a POST to /instructors . User is coming in null. Is there something I am missing to get JPA to tie the two together? I have tried adding CascadeType.ALL onto the field and that only throws a detached persist exception.
Leave the CascadeType.ALL to Instructor like you already tried:
#ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.ALL)
#JoinColumn(name = "user_id")
private User user;
In addition add the following to User. Seems to work with me. It provides the mapping information and makes JPA treat User managed
#OneToMany(mappedBy="user")//, cascade=CascadeType.ALL)
private List<Instructor> instructors = new ArrayList<>();
I have commented out the cascadeType in the above but it might be useful if you want to persist User wit all of its Instructors.
I have the following tables :
#Entity
#Table(name = "CUSTOMER")
public class Customers implements Serializable {
private static final long serialVersionUID = -5419345600310440297L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "cust")
#SequenceGenerator(name = "cust", sequenceName = "cust_ID_SEQ")
#Column(name = "CUSTOMER_ID")
private Long id;
#Column(name = "NAME")
private String name;
#OneToMany(mappedBy = "customer", cascade = CascadeType.PERSIST)
private Set<CustomerDeal> customerDeals;
//getters and setters goes here ....
}
#Entity
#Table(name = "DEALS")
public class Deals implements Serializable {
private static final long serialVersionUID = -7197428343863081750L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "deals_seq")
#SequenceGenerator(name = "deals_seq", sequenceName = "DEALS_SEQ")
#Column(name = "DEAL_ID")
private Long dealId;
#Column(name = "DEAL_NAME")
private String dealColName;
//getters setters
}
#Entity
#Table(name = "CUSTOMER_DEALS")
public class CustomerDeals implements Serializable {
private static final long serialVersionUID = -4249326793843278525L;
#EmbeddedId
private CustomerDealId customerDealId;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "CUSTOMER_ID", insertable = false, updatable = false)
private Customers customers;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "DEAL_ID", insertable = false, updatable = false)
private Deals deals;
//getters setters
}
#Embeddable
public class CustomerDealId implements Serializable {
private static final long serialVersionUID = 9086627167426987610L;
#Column(name = "DEAL_ID")
private Long dealId;
#Column(name = "CUSTOMER_ID")
private Long customerId;
}
however when I try to create a new customer
Customer cust - new Customer ()
cust.setName("Foo")
CustomerDeals custDeals = new CustomerDeals()
Set<CustomerDeal> custDealsSet = new HashSet<CustomerDeal>
CustomerDeal custDealsSet1 = new CustomerDeal()
CustomerDeal custDealsSet2 = new CustomerDeal()
custDealsSet1.setDeals(dealsRepository.findOne(1))//getting existing deal
custDealsSet1.customers(cust)
custDealsSet2.setDeals(dealsRepository.findOne(2))//getting existing deal
custDealsSet2.customers(cust)
custDealsSet.add(custDealsSet1)
custDealsSet.add(custDealsSet2)
cust.setCustomerDeals(custDealsSet)
customerRepository.saveAndFlush(cust)
customerRepository.saveAndFlush(cust)
I am getting
org.hibernate.id.IdentifierGenerationException: null id generated
for:class CustomerDeal
This is not duplication of this question
Your code that throws exception does not make sense so I guess it is not real code.
CustomerDeal has composite key, so you would not be able to retrieve it with dealsRepository.findOne(1), which means that you probably were retrieveing Deal not CustomerDeal but then the part would never compile:
Set<CustomerDeal> custDealsSet = new HashSet<CustomerDeal>();
custDealsSet.add(dealsRepository.findOne(1))
So, apart from that, I guess you were retrieving the existing deals. And you made a new customer. As the key of CustomerDeal depeneds on both customer and deal, both custumer and deal have to be set before persisting it which you probably forgot to do (and you got your exception). So it should look like:
Customer cust - new Customer ();
cust.setName("Foo");
CustomerDeals custDeal = new CustomerDeals();
custDeal.setCustomer(cust);
custDeal.setDeal(dealsRepository.findOne(1));
cust.getCustomerDeals().add(custDeal);
custDeal = new CustomerDeals();
custDeal.setCustomer(cust);
custDeal.setDeal(dealsRepository.findOne(2));
cust.getCustomerDeals().add(custDeal);
customerRepository.saveAndFlush(cust);
Now you are probably still in trouble. If you override the equals and hash on CustomerDeal so they are ID based (which typical code generator for entities does), both new CustomerDeals instances have them as null, so when you add them to the set the second one will override the first inserted (as null ids will be equals).
You also need to inform JPA that the ID will come from the relations.
In your CustomerDea you need to add #MapsId annotation (on both joins), like:
#MapsId("customerId")
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "CUSTOMER_ID", insertable = false, updatable = false)
private Customers customers;
Finally, unless your CustomerDeal table contains additional apart from CUSTOMER_ID and Deal_ID, then, it is a simple joint table and should not be mapped at all. That way you will save yourself a lot of trouble.
The reason why you got the error mentioned above is due to a mapping issue(I cant figure out what exactly is wrong though). As a completely different approach, I have modified your mappings. I have tested this and it is working fine. The advantage for you with this mapping is that it makes the CustomerDeals class redundant. Please note that I have removed the sequences as I am using MySQL.
#Entity
#Table(name = "CUSTOMERS")
public class Customer implements Serializable {
private static final long serialVersionUID = -5419345600310440297L;
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "CUSTOMER_ID")
private Long id;
#Column(name = "NAME")
private String name;
#ManyToMany(cascade = {CascadeType.ALL}, fetch = FetchType.EAGER)
#JoinTable(
name="CUSTOMER_DEALS",
joinColumns = #JoinColumn( name="CUSTOMER_ID"),
inverseJoinColumns = #JoinColumn( name="DEAL_ID")
)
private Set<Deals> deals = new HashSet<Deals>();
//Setters and Getters to follow
}
The Deals Class will be
#Entity
#Table(name = "DEALS")
public class Deals implements Serializable {
private static final long serialVersionUID = -7197428343863081750L;
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name = "DEAL_ID")
private Long dealId;
#Column(name = "DEAL_NAME")
private String dealColName;
#ManyToMany(fetch = FetchType.EAGER, mappedBy = "deals")
private Set<Customer> customers = new HashSet<Customer>(0);
//Setters and Getters here
}
Finally the main method which does the insert.
Customer customer = new Customer();
customer.setName("NewCust2");
Deals deals = new Deals();
deals.setDealColName("Deal2");
customer.getDeals().add(deals);
customerRepository.save(customer);