I am trying to add a Transient property to my Embeddable class. Here is what I have:
#NoArgsConstructor
#AllArgsConstructor
#Data
#Builder
#Embeddable
public class PackageProduct
{
#Field
private String productId;
#Transient
private Product product;
}
And PackageProduct is used in Package.java like this;
#ElementCollection(targetClass=PackageProduct.class, fetch = FetchType.EAGER)
private Set<PackageProduct> packageProducts;
However, this throws the following exception:
Caused by: org.hibernate.MappingException: Could not determine type for: *.*.*.Product, at table: Package_packageProducts, for columns: [org.hibernate.mapping.Column(packageProducts.product)]
The exception is no longer thrown if I annotate my PackageProduct class with this:
#Access(AccessType.FIELD)
I am trying to understand why it works with the class level #Access annotation. Any help is appreciated. Thanks.
In hibernate either you can apply all annotations on fields or methods, simultaneously mix use is not allow.To override this #Access is needed.In your product class if you are using such case, rectify this.
Related
I'm using Spring and JPA (Hibernate with MySQL) and Lombok also.
Hi have this part of my entities:
#Data
#AllArgsConstructor
#NoArgsConstructor
#Entity
#Table(name = "entitya")
public class EntityA implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name="ea_id")
Long id;
....
#ManyToOne
#JoinColumn(name="g_id", nullable=false)
private Group group;
....
}
#Data
#AllArgsConstructor
#NoArgsConstructor
#Entity
#Table(name = "group")
public class Group implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name="g_id")
private Long id;
#OneToMany(mappedBy="group")
private List<EntityA> enitiesA = new ArrayList<>();
...
}
I implemented also the repository extends JPARepository.
Into my controllers, if I try to retrieve an EntityA by Id I obtain this exception:
failed to lazily initialize a collection of role: com.mytest.entity.Group.enitiesA, could not initialize proxy - no Session
For me it's strange because I need to retrieve only the object. I not use some getter methods on this. So, in theory, using the default fetch types, I don't need to have also the group list.
What's wrong?
Are you debugging your object with toString()?
In case it could be an error caused by the #Data annotation.
The generated toString() method contains all fields, so it might call the enitiesA variable, producing the lazy initialization error.
https://mdeinum.github.io/2019-02-13-Lombok-Data-Ojects-Arent-Entities/
Likely it's because you're accessing group.enitiesA outside of the transactional boundaries. If you want to do this, you can eager fetch them by adding eager fetch type to your OneToMany mapping such as
#OneToMany(mappedBy="group", fetch = FetchType.EAGER)
This will load the entire object graph when the parent is loaded.
If you still want to do lazy loading, look to encapsulate all of the calls into the children under the session that loaded the parent.
I have an alert table which is transactional and an alert type table which is master. I would like to send out an email whenever an alert is added to the table, so I figured I would use PrePersist. However, in my email, I want to include some information that is included in the alert type table.
I have tried to add a reference to the AlertTypeRepository in the Alert class but I can't because my alert class is a #Table and alertTypeRepository is not a column.
Below is my Alert class
#Entity
#Table
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
public class Alert {
#Id
#GeneratedValue
int id;
#Column
String name;
#Column
String alertTypeId;
#Column
String detailedMessage;
#Column
String status;
#Temporal(TemporalType.TIMESTAMP)
Date time;
}
Below is my AlertType class
#Entity
#Table
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
public class AlertType {
#Id
#GeneratedValue
int id;
#Column
String name;
#Column
String header;
#Column
String footer;
#Column
String summary;
#Column
String deliveryType;
#Column
Boolean active ;
#Column
String recipients;
}
I would like to have a PrePersist function inside of the Alert class. That allows me to access its corresponding header and footer from the AlertType class.
I figured out a solution so I hope this helps anyone facing a similar issue. Basically I had to create an EntityListener to the Alert class and then add the following class.
#Component
public class AlertListener {
static AlertTypeRepository alertTypeRepository;
#Autowired
public void init(AlertTypeRepository alertTypeRepository)
{
this.alertTypeRepository = alertTypeRepository;
}
#PrePersist
public void prePersist(Alert alert) {
List<AlertType> alertType= this.alertTypeRepository.findAll();
}
}
As I know the are two approaches to archive the purpose. Your alterType is not managed by Spring .
Define a JPA EntityListener and apply it on your entity class, which does not seem to interest you.
The second approach, annotated your entity with Spring #Configurable annotation:
#Configurable(preConstruction = true)
class AlterType{
#Inject YourRepository bean as normal.
}
To make it work. Firstly you have to add aspectj related jars into your project dependencies. Secondly you can choose load-time weaving or compile-time weaving to handling the injection for you class.
There is an example of aspectj compiler config in Maven can be used for compile-time weaving(note, just for aspectj compiler maven plugin config, I did not use #Configurable here.).
I just try to create a CRUD Web Application with Spring Boot and I found that there is a problem with using Java Double Brace Initialization in the framework.
Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessApiUsageException: Unknown entity: com.example.service.impl.FileImageServiceImpl$1; nested exception is java.lang.IllegalArgumentException: Unknown entity:
I have the #Entity class:
#Entity
public class RandomEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
//Getter and Setter
}
A #RestController
#RestController
public class RandomController{
#Autowired
private RandomRepository randomRepository;
#GetMapping("/create")
public String create(){
RandomEntity rdEntity = new RandomEntity(){{
setName("Bla Bla");
}};
return randomRepository.save();
}
}
Here is the repository
public interface RandomRepository extends CrudRepository<RandomEntity, Long> {
}
But when I change Java Double Brace Initialization to Normal Initialization, the Application run properly.
Do you know why is that?
Thank you so much!
It may look like a nifty shortcut that just calls the constructor of your class followed by some initialization methods on the created instance, but what the so-called double-brace initialization really does is create a subclass of your Entity class. Hibernate will no longer know how to deal with that.
So try to avoid it. It has a lot of overhead and gotchas just to save you a few keystrokes.
I just want to complete the answer of #Thilo, If you want a clean code use Builder design pattern, now you can implement this Design easily via Lombok library, so you can Just annotate your Entity like so :
#Entity
#Getter #Setter #NoArgsConstructor #AllArgsConstructor
#Builder(toBuilder = true)
class RandomEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
}
So there are really some cool annotations, for example #Getter and #Setter to avoid all that getters and setters, #Builder(toBuilder = true) to work with builder design so your controller can look like :
#GetMapping("/create")
public RandomEntity create() {
// Create your Object via Builder design
RandomEntity rdEntity = RandomEntity.builder()
.name("Bla Bla")
.build();
// Note also here save should take your Object and return RandomEntity not a String
return randomRepository.save(rdEntity);
}
I'm trying to implement a Repository to work with Views. The fact is that I'm trying to use the SimpleJpaRepository implementation, but I'm getting a lot of errors on execution time because my DTO is not an #Entity. It is only a #Table, and it seems that this kind of elements are not mapped into the Metamodel of JPA.
This is my DTO:
#Table(name = "v_language")
public class VLanguage {
#Column(name = "isocode")
private String isocode;
#Column(name = "name")
private String name;
#Column(name = "isdefault")
private String isdefault;
// getters and setters
...
}
I tried to define a customized base repository with minimal functionality (only a findAll() method) with the same implementation of SimpleJpaRepository, but when building the Query it fails when doing:
Root<U> root = query.from(domainClass);
With this exception:
Caused by: java.lang.IllegalArgumentException: Not an entity: class es.prodevelop.pui.common.jpa.model.views.dto.VLanguage
at org.hibernate.jpa.internal.metamodel.MetamodelImpl.entity(MetamodelImpl.java:194)
at org.hibernate.jpa.criteria.QueryStructure.from(QueryStructure.java:124)
at org.hibernate.jpa.criteria.CriteriaQueryImpl.from(CriteriaQueryImpl.java:156)
at es.prodevelop.pui.common.jpa.configuration.AbstractRepository.applySpecificationToCriteria(AbstractRepository.java:213)
at es.prodevelop.pui.common.jpa.configuration.AbstractRepository.getQuery(AbstractRepository.java:174)
at es.prodevelop.pui.common.jpa.configuration.AbstractRepository.findAll(AbstractRepository.java:151)
...
Does anybody know how to solve it?
you are missing the #Entity annotation.
please annotate your class and try again.
I have 4 persistent classes which all have the same fields (exactly) the only 3 difference between them is 1) the class name, 2) the table name and 3) the data. i am aware that this might seem strange to some but trust me there is a good reason which i won't go into here.
now, i'm using hibernate annotations to configure my class which should work like so:
#Entity
#Table(name = "store")
public class Store
{
#Id
#Column(name = "unique_id")
protected String id;
#Column
protected String category;
...
}
.. and this does work, for a single stand-alone class, however there are many fields to map and i'd like to do it all in one hit for all four similar classes, ie:
public class StoreBase
{
#Id
#Column(name = "unique_id")
protected String id;
#Column
protected String category;
...
}
#Entity
#Table(name = "store1")
public class Store1 extends StoreBase
{}
#Entity
#Table(name = "store2")
public class Store2 extends StoreBase
{}
#Entity
#Table(name = "store3")
public class Store3 extends StoreBase
{}
#Entity
#Table(name = "store4")
public class Store4 extends StoreBase
{}
however when attempting this i get the following exception:
Caused by: org.hibernate.AnnotationException: No identifier specified for entity: package.entities.Store1
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:672)
at org.hibernate.cfg.AnnotationConfiguration.processArtifactsOfType(AnnotationConfiguration.java:546)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:291)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1292)
at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:867)
i'm guessing this is because the super class is not being searched for the identifier?
is there a way to utilise inheritance in this context?
thanks, paul.
#MappedSuperclass
public class StoreBase
See docs for more info.
Have a look at #MappedSuperclass.