There is a problem about generating id while persisting into database.
I added the following code to my jpa entity file, however I'm getting 0 for personid.
#Id
#Column(unique=true, nullable=false, precision=10, name="PERSONID")
#SequenceGenerator(name="appUsersSeq", sequenceName="SEQ_PERSON", allocationSize=1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "appUsersSeq")
private long personid;
EjbService:
#Stateless
public class EjbService implements EjbServiceRemote {
#PersistenceContext(name = "Project1245")
private EntityManager em;
#Override
public void addTperson(Tperson tp) {
em.persist(tp);
}
}
0 is default value for long type. The id will be set after invoking select query for the related sequence, which commonly is executed when you persist the entity. Are you persisting the entity? In case yes, post the database sequence definition to check it.
Related
I have a Spring Boot application using Spring Data REST. I have a domain entity called User with a boolean field isTeacher. This field has been already setup by our DBA in the User table with type bit and a default value of 1:
#Data
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id; // This Id has been setup as auto generated in DB
#Column(name = "IS_TEACHER")
private boolean isTeacher;
}
And the User repository:
public interface UserRepository extends CrudRepository<User, Long>{
}
I was able to add a new user by giving the below request and POST to http://localhost:8080/users, a new user was created in the DB having isTeacher value 1:
{
"isTeacher" : true
}
However, when I tried to change IS_TEACHER by giving PATCH (or PUT) and this request:
{
"isTeacher" : false
}
The response showed that "isTeacher" is still true and the value didn't get changed in the table either. Can someone please let me know why this is happening?
The issue is due to #Data annotation of lombok is ignoring if you have a field that start with isXx it generates getters and setters to boolean with isTeacher for getters and setTeacher for setters then you are not able to update correctly your property, if you put "teacher" when updating should work but you should solve this by overriding that setter.
#Setter(AccessLevel.NONE) private boolean isTeacher;
public void setIsTeacher(boolean isTeacher) {
this.isTeacher = isTeacher;
}
I have two entities, Books and Comments, in a one to many relationship (one book can have many comments). I want to be able to list books and number of comments about a book. I want it denormalized, meaning the books entity will have a counter that has number of comments for that book, and it will be updated every time a comment is entered (just playing with the concept, no need to discuss about the need of denormalizing here).
I think (correct me if I am wrong) this could be easily done with a trigger in the database (whenever a new comment is created, update a counter in the books table to the corresponding bookId), but for the sake of learning I want to do it through JPA, if it makes sense.
What I have so far: //omitted some annotations, just general info
Boks entity:
#Entity
public class Books {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String title;
private String author;
private Long numComments;
// getters and setters...
}
Comments entity:
#Entity
public class Comments {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String comment;
private Long authorId;
private Long bookId;
// getters and setters...
}
Books repository: I added here a query to perform the update
/**
* Spring Data JPA repository for the Books entity.
*/
public interface BooksRepository extends JpaRepository<Books,Long> {
#Modifying
#Query("UPDATE Books v SET v.numComments = v.numComments + 1 WHERE v.id = :bookId")
int updateCounter(#Param("bookId")Long bookId);
}
And now the question: What next? I think I can put the update of the Books entity annotating with #PostPersist a method of the entity Comments, but I have been unsuccessful so far. I can imagine something like this:
#PostPersist //This function in the entity Comments
protected void updateBooks() {
//Likely some call to the repository here that updates the count
// in books the info we have from current entity.
}
Any idea on how to do this? Some best practices about this kind of denormalization in JPA? Better to use the database triggers?
spring not managed your entity classes and your idea is possible but you must inject BooksRepository in enttiy class then stay at you get Nullpointerexception because spring not managed enttiy classes,The reason your BooksRepository not initlaized, try also read this post Bean injection inside a JPA #Entity and anotate entity class #Configurable after
try this
#PostPersist
protected void updateBooks(Comments comment) {
int totalComment = BooksRepository.updateCounter(comment.getBookId());
System.out.println(totalComment); // see totalComment in console
}
but good aprroach in service classes after call updateCounter when insert comment
example in your CommendService : when try a insert commend after call your updateCounter
if(comment.getBookId() != null) //Simple Control
{
CommentRepository.save(comment);
BooksRepository.updateCounter(comment.getBookId());
}
I am working on a Spring-MVC application which has 2 tables in database and 2 domain classes. Class Person has oneTOMany relation with class Notes. I would like to add Person and notes both in database. So I googled, to find out many MVC based examples for the same problem. However they seem to assume a few things :
Data is being added in a static manner by the developer, mostly through Static void main() or another class.
Data regarding all the classes which are related is added altogether, eg : Table A has oneToMany relation, so the code will add data for both the tables in one class or one jsp file.
Other frameworks like Spring-Security at play(This point is understood).
So basically, similar examples with different names and developers is what I found. My problem is :
I don't have static void main, don't intend to use it.
I am adding data through HTML page wrapped inside JSP page.
I or the user will first register through the register form, just login later and then add notes, so I am not adding data for both tables at same time. (I have to believe this is possible by Hibernate)
Error :
org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.journaldev.spring.model.Person
org.hibernate.engine.internal.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:294)
org.hibernate.type.EntityType.getIdentifier(EntityType.java:537)
org.hibernate.type.ManyToOneType.isDirty(ManyToOneType.java:311)
org.hibernate.type.ManyToOneType.isDirty(ManyToOneType.java:321)
org.hibernate.type.TypeHelper.findDirty(TypeHelper.java:294)
Person Model :
#Entity
#Table(name="person")
public class Person implements UserDetails{
private static final GrantedAuthority USER_AUTH = new SimpleGrantedAuthority("ROLE_USER");
#Id
#Column(name="id")
#GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "person_seq_gen")
#SequenceGenerator(name = "person_seq_gen",sequenceName = "person_seq")
private int id;
#OneToMany(cascade = CascadeType.ALL,mappedBy = "person1")
private Set<Notes> notes1;
public Set<Notes> getNotes1() {
return notes1;
}
public void setNotes1(Set<Notes> notes1) {
this.notes1 = notes1;
}
Notes model :
#Entity
#Table(name="note")
public class Notes {
#Id
#Column(name="noteid")
#GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "note_gen")
#SequenceGenerator(name = "note_gen",sequenceName = "note_seq")
private int noteId;
#ManyToOne
#JoinColumn(name = "id")
private Person person1;
public Person getPerson1() {
return person1;
}
public void setPerson1(Person person1) {
this.person1 = person1;
}
NotesDAOImpl :
#Transactional
#Repository
public class NotesDAOImpl implements NotesDAO{
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sf){
this.sessionFactory = sf;
}
#Override
public void addNote(Notes notes, int id) {
Session session = this.sessionFactory.getCurrentSession();
session.save(notes);
}
SQL schema :
CREATE TABLE public.person (
id INTEGER NOT NULL,
firstname VARCHAR,
username VARCHAR,
password VARCHAR,
CONSTRAINT personid PRIMARY KEY (id)
);
CREATE TABLE public.note (
noteid INTEGER NOT NULL,
sectionid INTEGER,
canvasid INTEGER,
text VARCHAR,
notecolor VARCHAR,
noteheadline VARCHAR,
id INTEGER NOT NULL,
CONSTRAINT noteid PRIMARY KEY (noteid)
);
ALTER TABLE public.note ADD CONSTRAINT user_note_fk
FOREIGN KEY (id)
REFERENCES public.person (id)
ON DELETE NO ACTION
ON UPDATE NO ACTION
NOT DEFERRABLE;
Btw, the id in addNote method is just me checking if SpringSecurity is actually sending userid, and has properly loggedin, debug purpose.
So, I am unable to add notes once user is logged in, what am I doing wrong? Or this is not possible with Hibernate. In that case, let me find a gun to shoot myself.. :P
Your code will try to save notes. But these notes will not be linked to any Person. You have to do below sequence of operation.
Find the logged in person or the person for which you want to save the notes.
Create notes object which will be in transient state.
Attach notes to the person.
If it is bidirectional relationaship, then person to notes.
Below is the code template.
#Transactional
#Repository
public class NotesDAOImpl implements NotesDAO{
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sf){
this.sessionFactory = sf;
}
#Override
public void addNote(Notes notes, int id) {
Session session = this.sessionFactory.getCurrentSession();
Person person = getPerson(); // this method should get logged in person or the person for whom you want to save the notes.
if (person.getNotes() == null) {
Set<Note> notes = new HashSet<Note>();
person.setNotes(notes);
}
person.getNotes().add(note);
note.setPerson(person); // If bidirectional relationship.
session.update(person); // if update does not work, try merge();
}
Also make sure you have cascade type set to MERGE in person entity on notes field.
Note: Above code is just example from your code and may have some compilation error. please correct according to your requirement.
I have to JPA Entities defined with a bidirectional relationship many to one, hereby:
#Entity
public class Department implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#SequenceGenerator(name="DEPARTAMENTO_ID_GENERATOR",sequenceName="DEPARTAMENTO_SEQ")
#GeneratedValue(strategy=GenerationType.SEQUENCE,generator="DEPARTAMENTO_ID_GENERATOR")
#Column(name="DEP_ID")
private long id;
#Column(name="DEP_DESC")
private String desc;
//bi-directional many-to-one association to Academico
#OneToMany(mappedBy="department")
private Set<Proffesor> proffesors;
//getters and setters
}
#Entity
#Table(name="ACADEMICOS")
public class Proffesor implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#SequenceGenerator(name="ACADEMICOS_ID_GENERATOR", sequenceName="ACADEMICOS_SEQ")
#GeneratedValue(strategy=GenerationType.SEQUENCE,generator="ACADEMICOS_ID_GENERATOR")
#Column(name="ACD_ID")
private long id;
#ManyToOne(cascade={CascadeType.PERSIST,CascadeType.MERGE})
#JoinColumn(name="ACD_DEPADSCRITO_DEP")
private Department department;
// getters and setters.
}
After in a transactional Spring service I have the next code to manipulate the entities in this way.
#Transactional (propagation=Propagation.REQUIRED)
public void createDepartmentWithExistentProffesor(String desc,Long idAvaiableProf) {
// new department
Department dep = new Department();
dep.setDesc(desc);
HashSet<Proffesor> proffesors = new HashSet<Proffesor>();
dep.setProffesors(proffesors);
// I obtain the correct attached Proffesor entity
Proffesor proffesor=DAOQueryBasic.getProffesorById(idAvaiableProf);
// I asign the relationship beetwen proffesor and department in both directions
dep.addProffesors(proffesor);
// Persists department
DAODataBasic.insertDepartment(dep);
// The id value is not correct then Exception ORA-0221
System.out.println("SERVICIO: Departamento creado con id: " + dep.getId());
}
As I said in the comments the id of the new Department persisted is not a real database id inside the transaction, then it is produced an exception
Exception in thread "main" org.springframework.orm.jpa.JpaSystemException: org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
........
Caused by: java.sql.BatchUpdateException: ORA-02291: integrity restiction (HIBERNATE_PRB.FK_ACD2DEP) violated - primary key don't found
I've tried in a test, persist the new departmen entity with no relationship with Proffesor and I've seen that the id of the new department persisted entity has not a valid value inside the transaction but out of the transaction already the id has a correct value.
But I need the correct value inside the transaction.
Can anybody help me?
Thank you in advance.
try this
#OneToMany(mappedBy="department",cascade = CascadeType.PERSIST)
private Set<Proffesor> proffesors;
I've created a simple EJB application that uses JPA for persistence and have a problem whereby optimistic locking is not functioning as I would have expected.
The application contains a class named Site which defines the model for a table named SITE in the database. The SITE table contains a column named ROW_VERSION which is referenced in the Site class using the #version annotation.
Whenever the record is updated, the ROW_VERSION is incremented by 1. So far, so good.
The problem arises when the row has changed in the time between the application reading the row using the EntityManager find method and the row being updated by the EntityManager merge method. As the ROW_VERSION for the row has been incremented by 1 and therefore is not the same as when the EntityManager find method was called, I would expect an OptimisticLockException to be thrown, but instead the changes are written to the table and in turn overwriting the changes made by the other process.
The application is running on WebSphere 8.5 and is using OpenJPA provided by the container.
Have I mis-understood how optimistic locking is supposed to work or is there something else that I need to do to make the OptimisticLockException occur?
The Site class is as follows:
#Entity
#Table(name="SITE")
public class Site {
#Id
#Column(name="SITE_ID")
private int id;
#Column(name="SITE_NAME")
private String siteName;
#Column(name="SITE_ADDRESS")
private String address;
#Column(name="ROW_VERSION")
#Version
private long rowVersion;
//getters and setters
}
The application makes uses of the Generic DAO wrapper class to invoke the EntityManager methods. The contents of the class are as follows:
public abstract class GenericDAO<T> {
private final static String UNIT_NAME = "Test4EJB";
#PersistenceContext(unitName = UNIT_NAME)
private EntityManager em;
private Class<T> entityClass;
public GenericDAO(Class<T> entityClass) {
this.entityClass = entityClass;
}
public T update(T entity) {
return em.merge(entity);
}
public T find(int entityID) {
return em.find(entityClass, entityID);
}
//other methods
}
Update - I've done some more investigation and have found this http://pic.dhe.ibm.com/infocenter/wasinfo/v8r0/index.jsp?topic=%2Fcom.ibm.websphere.nd.multiplatform.doc%2Finfo%2Fae%2Fae%2Fcejb_genversionID.html but even when I've added the #VersionColumn and #VersionStrategy annotations I still cannot get the OptimisticLockException to be thrown.