hibernate inheritance : How to protect base class entry on child class deletion - java

I have some trouble with Hibernate 4 and inheritance:
I use a ChildData class which inherit from BaseData by a JOIN inheritance strategy. My mapping is done by annotation in classes.
Everything is working fine except that when I delete a ChildData instance (with session.delete() or with a Hql query) the BaseData entry is also deleted.
I understand that in most case this is the awaited behavior, but for my particular case, I would like to preserve the BaseData entry no matter what for history purpose.
In other words I want all actions on the child class to be cascaded to base class except deletion.
I have already tried #OnCascade on the child class, with no success.
Is it a way to achieve this by code or do I have to use a SQL Trigger ON DELETE ?
EDIT :
Base Class
#Entity
#Table(name = "dbBenchHistory", uniqueConstraints = #UniqueConstraint(columnNames = "Name"))
#Inheritance(strategy = InheritanceType.JOINED )
public class DbBenchHistory implements java.io.Serializable {
private int id;
private String name;
private String computer;
private String eap;
private Date lastConnexion;
private Set<DbPlugin> dbPlugins = new HashSet<DbPlugin>(0);
private Set<DbSequenceResult> dbSequenceResults = new HashSet<DbSequenceResult>(
0);
public DbBenchHistory() {
}
public DbBenchHistory(int id, String name) {
this.id = id;
this.name = name;
}
public DbBenchHistory(int id, String name, String computer, String eap,
Date lastConnexion, Set<DbPlugin> dbPlugins,
Set<DbSequenceResult> dbSequenceResults) {
this.id = id;
this.name = name;
this.computer = computer;
this.eap = eap;
this.lastConnexion = lastConnexion;
this.dbPlugins = dbPlugins;
this.dbSequenceResults = dbSequenceResults;
}
#Id
#Column(name = "Id", unique = true, nullable = false)
#GeneratedValue(strategy=GenerationType.IDENTITY)
public int getId() {
return this.id;
}
public void setId(int id) {
this.id = id;
}
//Getters/Setters
Child Class :
#Entity
#Table(name = "dbBench")
#OnDelete(action=OnDeleteAction.NO_ACTION)
public class DbBench extends DbBenchHistory {
private Set<DbProgram> dbPrograms = new HashSet<DbProgram>(0);
private Set<DbUser> dbUsers = new HashSet<DbUser>(0);
public DbBench() {
}
public DbBench(Set<DbProgram> dbPrograms,
Set<DbUser> dbUsers) {
this.dbPrograms = dbPrograms;
this.dbUsers = dbUsers;
}
//Getters/Setters
But I'm starting to think that I was wrong from the beginning and that inheritance was not the good way to handle this. If nothing shows up I will just go for BenchHistory - Bench being a simple one-to-one relationship
EDIT2 :
I edit while I can't answer my own question for insuficient reputation
I feel completly stupid now that I found the solution, that was so simple :
As I said, I was using hibernate managed methods : session.delete() or hql query. Hibernate was doing what he was supposed to do by deletintg the parent class, like it would have been in object inheritance.
So I just bypass hibernate by doing the deletion of the child class with one of the simplest SqlQuery on earth. And the base class entry remain untouched.
I understand that I somehow violate the object inheritance laws, but in my case it is really handy.
Thanks to everyone for your time, and believ me when I say I'm sorry.

I don't think Hibernate/JPA supports this. What you basically want is conversion from a subclass to a superclass, and not a cascading delete. When you have an object of the subclass, the members from the superclass are treated no different than the members of the subclass.
This can be solved through writing some logic for it though:
public void deleteKeepSuperclassObject(final ChildData childData) {
final BaseData baseDataToKeep = new BaseData();
//populate baseDataToKeep with data from the childData to remove
em.persist(baseDataToKeep);
em.remove(childData);
}

Related

Is it possible to replace or modify values from projections or anonymous classes?

In my application I am using projections to map *Entity objects to simplified or modified versions of the actual record in the database.
However, I have a particular use case where I am required to replace a certain value from one of the nested projections. Since these are interfaces and also get proxied by Spring, I am not sure if what I want is actually possible but to bring it down to one very simpel example:
Assume I have a UserEntity and a User projection. For my User projection I can simply execute:
User user = this.userEntityRepository.findById(userId);
However, if I want to change something, I am not sure if that is possible. Namely, I cannot do something like this:
if (user.getAge() < 18) {
user.setDisplayName(null);
}
Now, I am aware that I could create an anonymous class new User() { .. } and just pass in the values I required but in my case the objects are nested and hence this is not an option.
The question
Is there another way to replace a value, e.g. displayName as above, without using an anonymous class?
Elaborative example
Reading the following is not really necessary but in order to illustrate my issue in more detail I have pseudo-coded an example that shows a bit closer what the problem is in my particular case.
We have a simple UserEntity:
#Entity
#Table(name = "app_user")
public class UserEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column
private String firstName;
#Column
private String lastName;
#Column
private Integer age;
// Setter & Getter ..
}
#Entity
#Table(name = "event")
public class EventEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#OneToMany(mappedBy = "event")
private List<EventAttendeeEntity> attendees;
// ..
}
We have a table which maps users to events:
#Entity
#Table(name = "attendee")
public class AttendeeEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne
private EventEntity event;
#ManyToOne
private UserEntity user;
// ..
}
Further, we have projections for these entities which we prepare as views for our clients:
/*
* Projection for User
*/
public interface User {
// All the properties ..
}
/*
* Projection for AttendeeEntity
*/
public interface Attendee {
Long getId();
User getUser();
}
/*
* Projection for EventEntity
*/
public interface Event {
Long getId();
String getName();
List<Attendee> getAttendees();
}
In one of the services we fetch UserEvent. Here, let's say, we want to remove the names of all users below 18 and still return userEvent we just fetched.
public Event getEvent(Long id, Boolean anonymize) {
Event event = this.eventRepository.findById(id);
// The "anonymize" is to highlight that I cannot
// simply solve this in a User-projection
if (!anonymize) {
return event;
}
event
.getAttendees();
.stream()
.peek(attendee -> {
User user = attendee.getUser();
if(user.getAge() < 18) {
// Here we create a new user object without a name
User newUser = new User() {
#Override
String getDisplayName() { return null; }
#Override
Integer getAge() { return user.getAge(); }
}
// !! This is where we hit the problem since we cannot
// !! replace the old user object like this
attendee.setUser(newUser);
}
});
return event;
}
One solution is to use SPEL in you projection selector. Please try
public interface Attendee {
Long getId();
#Value("#{target.user.age >= 18 ? target.user : new your.package.UserEntity()}")
User getUser();
}
Replace you.package with the package of UserEntity. Pay attention to put new UserEntity() and not new User(). This way an empty model will be projected as an empty interface User.
You can't use projections to update your code.
As a final note, it's important to remember that projections and excerpts are meant for the read-only purpose.
API Data Rest Projections Baeldung

JPA: Adding new entry to a many-to-many taking long time

im having a problem when adding a new entry in a many-to-many relationship because the list is huge. Ex:
Item item = new Item(1);
Category cat = dao.find(1, Category.class);
List<Category> list = new ArrayList<>();
list.add(cat);
item.setCategoryList(list);
cat.getItemList().add(item);
The problem is that the Category Itens list is huge, with a lot of itens, so performing the cat.getItemList() takes a very long time. Everywhere i look for the correct way to add a many-to-many entry says that a need to do that. Can someone help?
Edit:
A little context: I organize my itens with tags, so 1 item can have multiple tags and 1 tag can have multiple itens, the time has pass and now i have tags with a lot of itens ( > 5.000), and now when i save a new item with one of thoses tags it takes a long time, i have debuged my code and found that most of the delay is in the cat.getItensList() line, with makes sense since it has a extensive list o itens. I have searched a lot for how to do this, and everyone says that the correct way to save a entry in a many-to-many case is to add to the list on both sides of the relationship, but if one side is huge, it will takes a lot of time since calling the getItensList() loads them in the context. Im looking for a way to save my item refering the tag witout loading all of the itens of that tag.
Edit 2:
My classes:
Item:
#Entity
#Table(name = "transacao")
#XmlRootElement
public class Transacao implements Serializable {
#ManyToMany(mappedBy = "transacaoList")
private List<Tagtransacao> tagtransacaoList;
...(other stuff)
}
Tag:
#Entity
#Table(name = "tagtransacao")
#XmlRootElement
public class Tagtransacao implements Serializable {
#JoinTable(name = "transacao_has_tagtransacao", joinColumns = {
#JoinColumn(name = "tagtransacao_idTagTransacao", referencedColumnName = "idTagTransacao")}, inverseJoinColumns = {
#JoinColumn(name = "transacao_idTransacao", referencedColumnName = "idTransacao")})
#ManyToMany
private List<Transacao> transacaoList;
...(other stuff)
}
Edit 3:
WHAT I DID TO SOLVE:
As answered by Ariel Kohan, i tried to do a NativeQuery to insert the relationship:
Query query = queryDAO.criarNativeQuery("INSERT INTO " + config.getNomeBanco() + ".`transacao_has_tagtransacao` "
+ "(`transacao_idTransacao`, `tagtransacao_idTagTransacao`) VALUES (:idTransacao, :idTag);");
query.setParameter("idTransacao", transacao.getIdTransacao());
query.setParameter("idTag", tag.getIdTagTransacao());
I was able to reduce the time of que query from 10s to 300milis what it is impressive. In the end its better for my project that it is already runnig to do that instead of creating a new class that represents the many-to-many reletionship. Thanks to everyone who tried to help \o/
In this case, I would prevent your code from load the item list in memory.
To do that, I can think about two options:
Using a #Modyfing query to insert the items directly in the DB.
[Recommended for cases where you want to avoid changing your model]
You can try to create the query using normal JPQL but, depending on your model, you may need to use a native query. Using native query would be something like this:
#Query(value = "insert into ...", nativeQuery = true)
void addItemToCategory(#Param("param1") Long param1, ...);
After creating this query, you will need to update your code removing the parts where you load the objects in memory and adding the parts to call the insert statements.
[Update]
As you mentioned in a comment, doing this improved your performance from 10s to 300milis.
Modify your Entities in order to replace #ManyToMany with #OneToManys relationship
The idea in this solution is to replace a ManyToMany relationship between entities A and B with an intermediate entity RelationAB. I think you can do this in two ways:
Save only the Ids from A and B in RelationAB as a composite key (of course you can add other fields like a Date or whatever you want).
Add an auto-generated Id to RelationAB and add A and B as other fields in the RelationAB entity.
I did an example using the first option (you will see that the classes are not public, this is just because I decided to do it in a single file for the sake of simplicity. Of course, you can do it in multiple files and with public classes if you want):
Entities A and B:
#Entity
class EntityA {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public EntityA() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
#Entity
class EntityB {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
public EntityB() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
RelationABEntity and RelationABId:
#Embeddable
class RelationABId implements Serializable {
private Long entityAId;
private Long entityBId;
public RelationABId() {
}
public RelationABId(Long entityAId, Long entityBId) {
this.entityAId = entityAId;
this.entityBId = entityBId;
}
public Long getEntityAId() {
return entityAId;
}
public void setEntityAId(Long entityAId) {
this.entityAId = entityAId;
}
public Long getEntityBId() {
return entityBId;
}
public void setEntityBId(Long entityBId) {
this.entityBId = entityBId;
}
}
#Entity
class RelationABEntity {
#EmbeddedId
private RelationABId id;
public RelationABEntity() {
}
public RelationABEntity(Long entityAId, Long entityBId) {
this.id = new RelationABId(entityAId, entityBId);
}
public RelationABId getId() {
return id;
}
public void setId(RelationABId id) {
this.id = id;
}
}
My Repositories:
#Repository
interface RelationABEntityRepository extends JpaRepository<RelationABEntity, RelationABId> {
}
#Repository
interface ARepository extends JpaRepository<EntityA, Long> {
}
#Repository
interface BRepository extends JpaRepository<EntityB, Long> {
}
A test:
#RunWith(SpringRunner.class)
#DataJpaTest
public class DemoApplicationTest {
#Autowired RelationABEntityRepository relationABEntityRepository;
#Autowired ARepository aRepository;
#Autowired BRepository bRepository;
#Test
public void test(){
EntityA a = new EntityA();
a = aRepository.save(a);
EntityB b = new EntityB();
b = bRepository.save(b);
//Entities A and B in the DB at this point
RelationABId relationABID = new RelationABId(a.getId(), b.getId());
final boolean relationshipExist = relationABEntityRepository.existsById(relationABID);
assertFalse(relationshipExist);
if(! relationshipExist){
RelationABEntity relation = new RelationABEntity(a.getId(), b.getId());
relationABEntityRepository.save(relation);
}
final boolean relationshipExitNow = relationABEntityRepository.existsById(relationABID);
assertTrue(relationshipExitNow);
/**
* As you can see, modifying your model you can create relationships without loading big list and without complex queries.
*/
}
}
The code above explains another way to handle this kind of things. Of course, you can make modifications according to what you exactly need.
Hope this helps :)
This is basically copied from a similar answer I gave earlier but similar question as well. The code below ran when I first write it but I changed the names to match this question so there might be some typos. The spring-data-jpa is a layer on top of JPA. Each entity has its own repository and you have to deal with that. For dealing with the many-to-many relations specifically in spring-data-jpa you can make a separate repository for the link table if you think it's a good idea.
#Entity
public class Item {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#OneToMany(mappedBy = "item", cascade = CascadeType.ALL, orphanRemoval = true)
private List<ItemCategory> categories;
#Entity
public class Category {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
#OneToMany(mappedBy = "category", cascade = CascadeType.ALL, orphanRemoval = true)
private List<ItemCategory> items;
#Entity
public class ItemCategory {
#EmbeddedId
private ItemcategoryId id = new ItemcategoryId();
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("itemId")
private Item Item;
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("categoryId")
private Category category;
public ItemCategory() {}
public ItemCategory(Item Item, Category category) {
this.item = item;
this.category = category;
}
#SuppressWarnings("serial")
#Embeddable
public class ItemCategoryId implements Serializable {
private Long itemId;
private Long categoryId;
#Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
ItemCategoryId that = (ItemCategoryId) o;
return Objects.equals(itemId, that.itemId) && Objects.equals(categoryId, that.categoryId);
}
#Override
public int hashCode() {
return Objects.hash(itemId, categoryId);
}
And to use it. Step 3 shows the way you are currently doing it and creates a read of the existing joins before doing the update. Step 4 just inserts a relation directly in the join table and does not cause a pre-read of the existing joins.
#Transactional
private void update() {
System.out.println("Step 1");
Category category1 = new Category();
Item item1 = new Item();
ItemCategory i1c1 = new ItemCategory(Item1, Category1);
categoryRepo.save(Category1);
ItemRepo.save(Item1);
ItemCategoryRepo.save(p1t1);
System.out.println("Step 2");
Category category2 = new Category();
Item item2 = new Item();
ItemCategory p2t2 = new ItemCategory(item2, category2);
ItemRepo.save(item2);
categoryRepo.save(category2);
ItemCategoryRepo.save(p2t2);
System.out.println("Step 3");
category2 = CategoryRepo.getOneWithitems(2L);
category2.getitems().add(new ItemCategory(item1, category2));
categoryRepo.save(Category2);
System.out.println("Step 4 -- better");
ItemCategory i2c1 = new ItemCategory(item2, category1);
itemCategoryRepo.save(i2c1);
}
I don't explicitly set the ItemCategoryId id's. These are handled by the persistence layer (hibernate in this case).
Note also that you can update ItemCategory entries either explicity with its own repo or by adding and removing them from the list since CascadeType.ALL is set, as shown. The problem with using the CascadeType.ALL for spring-data-jpa is that even though you prefetch the join table entities spring-data-jpa will do it again anyway. Trying to update the relationship through the CascadeType.ALL for new entities is problematic.
Without the CascadeType neither the items or categories lists (which should be Sets) are the owners of the relationship so adding to them wouldn't accomplish anything in terms of persistence and would be for query results only.
When reading the ItemCategory relationships you need to specifically fetch them since you don't have FetchType.EAGER. The problem with FetchType.EAGER is the overhead if you don't want the joins and also if you put it on both Category and Item then you will create a recursive fetch that gets all categories and items for any query.
#Query("select c from Category c left outer join fetch c.items is left outer join fetch is.Item where t.id = :id")
Category getOneWithItems(#Param("id") Long id);

Hibernate One to many Annotation Mapping

Hi I have a two tables like below .
1) Task - id,name
2) Resource - id,name,defaultTask(foreign key to Task.id)
The mapping is one to Many - one task can have many resource.
The code for Task is like below.
#Entity
public class Task implements Serializable {
private long m_id;
private String m_name;
#Id
#GeneratedValue(
strategy = GenerationType.AUTO
)
public long getId() {
return this.m_id;
}
public void setId(long id) {
this.m_id = id;
}
public String getName() {
return this.m_name;
}
public void setName(String name) {
this.m_name = name;
}
#OneToMany
#JoinColumn(
name = "defaultTask"
)
private List<Resource> m_relatedResources;
public List<Resource> getrelatedResources() {
return m_relatedResources;
}
public void setrelatedResources(List<Resource> relatedResources) {
m_relatedResources = relatedResources;
}
And the code for Resource class is like below.
#Entity
public class Resource implements Serializable {
private Long m_id;
private String m_name;
#Id
#GeneratedValue(
strategy = GenerationType.AUTO
)
public Long getId() {
return this.m_id;
}
public void setId(Long id) {
this.m_id = id;
}
public String getName() {
return this.m_name;
}
public void setName(String name) {
this.m_name = name;
}
Task m_task;
#ManyToOne
#JoinColumn(
name = "defaultTask"
)
public Task getTask() {
return this.m_task;
}
public void setTask(Task task) {
this.m_task = task;
}
}
When i execute it I am getting an error like
Initial SessionFactory creation failed.org.hibernate.MappingException: Could not determine type for: java.util.List, for columns: [org.hibernate.mapping.Column(relatedResources)]
What have i done wrong ?How can i fix the problem ?
You can't apply annotations to methods or fields randomly. Normally, you should apply your annotations the same way as #Id..
In Task class OneToMany should be like
#OneToMany
#JoinColumn(
name = "defaultTask"
)
public List<Resource> getrelatedResources() {
return m_relatedResources;
}
Field access strategy (determined by #Id annotation). Put any JPA related annotation right above each method instead of field / property as for your id it is above method and it will get you away form exception.
Also there appears to be an issue with your bidrectional mapping metntioned by #PredragMaric so you need to use MappedBy which signals hibernate that the key for the relationship is on the other side. Click for a really good question on Mapped by.
Many mistakes here:
you're annotating fields sometimes, and getters sometimes. Half of the annotation will be ignored: you must be consistent. It's one or the other.
You're not respecting the Java Bean naming conventions. The getter must be getRelatedResources(), not getrelatedResources().
A bidirectional association must have an owner side and an inverse side. In a OneToMany, the One is always the inverse side. The mapping should thus be:
.
#ManyToOne
#JoinColumn(name = "defaultTask")
public Task getTask() {
return this.m_task;
}
and
#OneToMany(mappedBy = "task")
public List<Resource> getRelatedResources() {
return m_relatedResources;
}
I also strongly advise you to respect the Java naming conventions. Variables should be named id and name, not m_id and m_name. This is especially important if you choose to annotate fields.
You're mixing annotating fields and getters in the same entity, you should move your #OneToMany to a getter
#OneToMany
#JoinColumn(mappedBy = "task")
public List<Resource> getrelatedResources() {
return m_relatedResources;
}
and yes, as the others mentioned, it should be mappedBy = "task". I'll upvote this teamwork :)
#JoinColumn is only used on owner's side of the relation, ToOne side, which is Resource#task in your case. On the other side you should use mappedBy attribute to specify bidirectional relation. Change your Task#relatedResources mapping to this
#OneToMany(mappedBy = "task")
private List<Resource> m_relatedResources;
Also, as #Viraj Nalawade noticed (and others, obviously), mapping annotations should be on fields or properties, whatever is used for #Id takes precedence. Either move #Id to field, or move #OneToMany to getter.

How to add a JPA relationship against legacy database

I'm coming from a C# entity framework background and looking at JPA in a Java project so I'm hoping that what I'm facing is just a conceptual problem.
I've got a legacy database that I can't alter the schema of and I need to write a DAL.
I've generated (simplified for the example) the following entities...
#Entity
#Table(name = "crag", catalog = "rad_dbo")
public class CragEntity {
private int id;
#Column(name = "id")
#Id
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
private int fkSubRegionId;
#Column(name = "fk_subRegionId")
#Basic
public int getFkSubRegionId() {
return fkSubRegionId;
}
public void setFkSubRegionId(int fkSubRegionId) {
this.fkSubRegionId = fkSubRegionId;
}
}
and
#Table(name = "subRegion", catalog = "rad_dbo")
#Entity
public class SubRegionEntity {
private int id;
#Column(name = "id")
#Id
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
I've tried adding a relationship to CragEntity so that I can access its subRegion
#ManyToOne
#JoinColumn(name="fk_SubRegionId",nullable=false)
private SubRegionEntity subRegion;
but when I try to run
select c from CragEntity c where c.subRegion.region = :area
I get an exception
java.lang.RuntimeException: org.hibernate.QueryException: could
not resolve property: subRegion of: uk.co.bmc.rad.dal.CragEntity
Hopefully this is possible and I'm being slow...
Many thanks in advance for any help!
In your query you are searching for the property "subRegion" though in your entity definition you have the name "fkSubRegionId", so you must change the var name or the query. ;)
EDIT: Sorry i misreaded the relation.
Can you access the property (without making an HQL query) with the relationship inside the code?
Unless, you want to pick only certain fields in your query I would recommend a query like:
from CragEntity c where c.subRegion.region='theRegion'
It turns out there were several issues - one conceptual, one with how IntelliJ had generated a relationship I was copying and one between the chair and keyboard...
IntelliJ had picked the region to subregion relationship with the owner at the "wrong" end - probably a schema issue rather than IntelliJ's fault. Once I realised that and figured out the fix I could copy that to CragEntity and SubRegionEntity
In CragEntity I added:
private SubRegionEntity subRegion;
#ManyToOne
#JoinColumn(name="fk_SubRegionId",nullable=false)
public SubRegionEntity getSubRegion() {
return subRegion;
}
public void setSubRegion(SubRegionEntity subRegion) {
this.subRegion = subRegion;
}
and then in SubRegionEntity I added:
private List<CragEntity> crags;
#OneToMany(mappedBy = "subRegion")
List<CragEntity> getCrags() {
return crags;
}
public void setCrags(List<CragEntity> crags) {
this.crags = crags;
}
Also, it seem that any entity class that is going to be one end of a relationship has to implement serializable (I guess the entities get serialized into the owner. So that needed adding onto SubRegionEntity and RegionEntity
The silliness on my part was of course that the query should have been c.subRegion.region.name otherwise I was comparing an object of type RegionEntity with a string... doh - very stupid mistake on my part.
I'm new to TDD but as always as soon as I wrote tests for what I thought should be happening with the existing code I was walked through my errors (and given google keywords by the exceptions and errors :-))

Hibernate MappingException

I'm getting this Hibernate error:
org.hibernate.MappingException: Could not determine type for:
a.b.c.Results$BusinessDate, for columns: [org.hibernate.mapping.Column(businessDate)]
The class is below. Does anyone know why I'm getting this error??
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"businessDate"
})
#XmlRootElement(name = "Results")
#Entity(name = "Results")
#Table(name = "RESULT")
#Inheritance(strategy = InheritanceType.JOINED)
#Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
public class Results implements Equals, HashCode
{
#XmlElement(name = "BusinessDate", required = true)
protected Results.BusinessDate businessDate;
public Results.BusinessDate getBusinessDate() {
return businessDate;
}
public void setBusinessDate(Results.BusinessDate value) {
this.businessDate = value;
}
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"raw",
"display"
})
#Entity(name = "Results$BusinessDate")
#Table(name = "BUSINESSDATE")
#Inheritance(strategy = InheritanceType.JOINED)
public static class BusinessDate implements Equals, HashCode
{
....
Update: This code was generated by HyperJaxB. So I don't claim to understand it all, just trying to make some changes to it!
Update2: Here's the full (yah it's big) src file
Using a static nested class as a field type is fine and supported. But Hibernate won't know how to map such a complex type to a column type (which is what the error message says).
So you'll need either to create a user type to handle this or to annotate the Results.BusinessDate field with a #OneToOne annotation to persist it in another table (I would also remove the #Inheritance which is useless but this is not the problem here).
Update: Just to clarify, using a user type or mapping the complex type with #OneToOne does work. The following code works perfectly (tested):
#Entity
public class EntityWithStaticNestedClass implements Serializable {
#Id
#GeneratedValue
private Long id;
#OneToOne
private EntityWithStaticNestedClass.StaticNestedClass nested;
public Long getId() { return id; }
public void setId(Long id) { this.id = id; }
public EntityWithStaticNestedClass.StaticNestedClass getNested() {
return nested;
}
public void setNested(EntityWithStaticNestedClass.StaticNestedClass nested) {
this.nested = nested;
}
#Entity
public static class StaticNestedClass implements Serializable {
#Id
#GeneratedValue
private Long id;
public Long getId() { return id; }
public void setId(Long id) { this.id = id; }
}
}
And both entities get well persisted in their respective tables. But you're not showing the entire code nor the exact error so I can't say why it didn't for you (maybe you're missing #Id etc).
That being said, if you don't want businessDate to be persisted at all, annotate it with #Transient (with JPA, fields are persistent by default):
Update: You can't mix field and property access. So you need to annotate getBusinessDate() with #Transienthere. Sorry, I couldn't guess that from the shown code and I thought it would be obvious.
Same comment as Kevin Crowell. You might also look at not using inner classes for entity types. I've actually never seen someone do that with Hibernate, so I'm not sure if it's even possible, or how you would map it.
The #Inheritance annotation on the BusinessDate inner class seems a little fishy too - the inner class is static, and does not inherit from another entity, unless Hibernate treats inner classes as "inherited."
Overall, not really sure what you're trying to accomplish, but you might be making your life harder than it should be. I would recommend not using inner classes, and just mapping all the entities in a more simple/straightforward fashion.

Categories

Resources