I've implemented a custom SequenceGenerator that I want to use in all my entities for the "id". But rather than having to do something like this for each entity:
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "XyzIdGenerator")
#GenericGenerator(name = "XyzIdGenerator",
strategy = "com.mycompany.myapp.id.BigIntegerSequenceGenerator",
parameters = {
#Parameter(name = "sequence", value = "xyz_id_sequence")
})
public BigInteger getId()
{
return id;
}
is there a way to apply this SequenceGenerator to ALL entities by default using vanilla Hibernate/JPA or perhaps by using Spring?
Just move the code segment to a super class, add add #MappedSuperclass to it. But, in that case, all your entity will use the same seq generator
#MappedSuperclass
public class SeqIdable implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "XyzIdGenerator")
#GenericGenerator(
name = "XyzIdGenerator",
strategy = "com.mycompany.myapp.id.BigIntegerSequenceGenerator",
parameters = {
#Parameter(name = "sequence", value = "xyz_id_sequence")
})
public BigInteger getId() {
return id;
}
}
Related
I'm getting an exception:
org.hibernate.TransientPropertyValueException:
object references an unsaved transient instance
- save the transient instance before flushing :
com.example.jpamapstruct.entity.Member.club ->
com.example.jpamapstruct.entity.Club
while saving the member entity:
#Transactional
public MemberDto save(MemberDto memberDto){
Member entity = memberMapper.toEntity(memberDto);
return memberMapper.toDto(repository.save(entity));
}
How to fix this case in a proper way?
Possible solution:
I can get and set a club object before saving a member but is it only one and the best approach in such scenario?
Member entity = memberMapper.toEntity(memberDto);
clubRepository.getReferencedById(memberDto.getClubId()).ifPresent(entity::setClub);
return memberMapper.toDto(repository.save(entity));
Questions:
Should I put this getReferencedById code explicity? I mean what if we have several child objects (unidirectional ManyToOne), for each we need to get data from DB.
Is there any way to handle this by JPA (Spring Data/JPA) "automatically"?
Maybe it is possible to hit DB only one time with f.e join fetch somehow for all childs (with using custom #Query or querydsl or criteria/specification)?
Next, hoow to handle collections (unidirectional manyToMany)? In my case set of events in member object. Also need to loop thru and get all objects one by one before saving member?
Where should I put such logic in a service or maybe better in a mapstuct mapper?
If so, how to use repositories in such mapper?
#Mapper(componentModel = "spring")
public interface MemberMapper extends EntityMapper<MemberDto, Member> {
#AfterMapping
default void afterMemberMapping(#MappingTarget Member m, MemberDto dto) {
var club = clubRepo.findById(m.getClub().getId())
m.setClub(club)
}
Source code:
#Entity
public class Club extends AbstractEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", nullable = false)
private Long id;
}
public class ClubDto extends AbstractDto {
private Long id;
}
#Entity
public class Member {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Long id;
// commented out as don't want to save child object as it should already exist
// #ManyToOne(cascade = CascadeType.ALL)
#ManyToOne
Club club;
#ManyToMany
#JoinTable(name = "member_events",
joinColumns = #JoinColumn(name = "member_id"),
inverseJoinColumns = #JoinColumn(name = "event_id")
)
List<Event> events = new ArrayList<>();
}
public class MemberDto {
private Long id;
private ClubDto club;
}
#MappedSuperclass
public abstract class AbstractEntity {
#Version
private Integer version;
}
public abstract class AbstractDto {
private Integer version;
}
//MemberMapper above
I have an entity
#Entity
data class Person (
#Id #GeneratedValue
val id: Long
)
But I noticed the values for id are consecutive. Is there a way to let Spring Boot make them more random?
You can create a custom identifier generator and use it.
#Entity
public class Book {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seq")
#GenericGenerator(
name = "seq",
strategy = "com.java.generators.SequenceIdGenerator",
parameters = {...})
private String id;
...
}
Here you should create com.java.generators.SequenceIdGenerator by own
A good tutorial about this
I am trying to do a simple task with Spring Data JPA derived queries and am unable to get the desired results from the query. Basically I have a Book which can have one or many Chapters with localization support for the Book as well as the Chapter. I want to create a query which would fetch a language specific book (with chapters) based on the Locale. Here are my four entities.
#Entity
#Getter
#Setter
public class Book {
#Id
#Column(name = "ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private int noOfPages;
/**
* Both mappings below are unidirectional #OneToMany
*/
#OneToMany(cascade = CascadeType.ALL)
#JoinColumn(name = "BOOK_ID", referencedColumnName = "ID")
private List<BookTranslation> bookTranslations;
#OneToMany(cascade = CascadeType.ALL)
#JoinColumn(name = "BOOK_ID", referencedColumnName = "ID")
private List<Chapter> chapters;
/**
* Constructor for JPA
*/
protected Book() {
}
public Book(int noOfPages, List<BookTranslation> bookTranslations, List<Chapter> chapters) {
this.noOfPages = noOfPages;
this.bookTranslations = bookTranslations;
this.chapters = chapters;
}
}
#Entity
#Getter
#Setter
public class BookTranslation {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Enumerated(EnumType.STRING)
private Language language;
private String name;
/**
* Constructor for JPA
*/
protected BookTranslation() {
}
public BookTranslation(Language language, String name) {
this.language = language;
this.name = name;
}
}
#Entity
#Getter
#Setter
public class Chapter {
#Id
#Column(name = "ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private int chapterNumber;
#OneToMany(cascade = CascadeType.ALL)
#JoinColumn(name = "CHAPTER_ID", referencedColumnName = "ID")
private List<ChapterTranslation> chapterTranslations;
/**
* Constructor for JPA
*/
protected Chapter() {
}
public Chapter(int chapterNumber, List<ChapterTranslation> chapterTranslations) {
this.chapterNumber = chapterNumber;
this.chapterTranslations = chapterTranslations;
}
}
#Entity
#Getter
#Setter
public class ChapterTranslation {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Enumerated(EnumType.STRING)
private Language language;
private String title;
/**
* Constructor for JPA
*/
protected ChapterTranslation() {
}
public ChapterTranslation(Language language, String title) {
this.language = language;
this.title = title;
}
}
public enum Language {
EN, FR
}
Below is the sample code, I am using to persist these entities. Ignore the #GetMapping please, this is just a sample.
#GetMapping("/persist-book")
public void persistBook() {
ChapterTranslation enChapter = new ChapterTranslation(Language.EN, "What is Java persistence?");
ChapterTranslation frChapter = new ChapterTranslation(Language.FR, "Qu'est-ce que la persistance Java?");
List<ChapterTranslation> chapterOneTranslation = new ArrayList<>();
chapterOneTranslation.add(enChapter);
chapterOneTranslation.add(frChapter);
Chapter chapterOne = new Chapter(1, chapterOneTranslation);
List<Chapter> chapters = new ArrayList<>();
chapters.add(chapterOne);
BookTranslation enBook = new BookTranslation(Language.EN, "JPA WikiBook in English");
BookTranslation frBook = new BookTranslation(Language.FR, "JPA WikiBook in French");
List<BookTranslation> bookTranslations = new ArrayList<>();
bookTranslations.add(enBook);
bookTranslations.add(frBook);
Book book = new Book(500, bookTranslations, chapters);
bookRepository.save(book);
}
My BookRepository looks as follows:
public interface BookRepository extends CrudRepository<Book, Long> {
List<Book> findBooksByBookTranslations_LanguageAndChapters_ChapterTranslations_Language(Language lang1, Language lang2);
}
Sample code I am using to retrieve the result.
#GetMapping("/english-book")
public List<Book> retrieveEnglishBook() {
return bookRepository.findBooksByBookTranslations_LanguageAndChapters_ChapterTranslations_Language(
Language.EN, Language.EN
);
}
My expected output is as attached in the image below.
One thing that I noticed from the Hibernate logs is that Hibernate makes a total of four select queries and the first query output is exactly what I need. However, since this a method name based query I don't suppose I can control that.
EDIT 1: Before trying out the answer, I was getting all books with all their locales returned, after changing my query to the one given in the accepted answer I was able to get the Book with the selected locale.
Please note: I also had to change all collections from using a List to a Set, more on this can be read about in the accepted answers link.
What you describe as a desired result is a single database result.
I guess what you mean by that is you expect to get all the books but only with the translations in a single language.
You don't describe what you actually get, so assume you are getting the book with all available translations.
Your desired result is beyond the capabilities of derived queries.
The different predicates of a derived queries all limit the root entities to be returned Book in your case. They should still have all references in tact.
You could achieve your goal with an annotated query like this:
public interface BookRepository extends CrudRepository<Book, Long> {
#Query("SELECT b FROM Book b
JOIN FETCH b.bookTranslations as bt
JOIN FETCH b.chapter as c
JOIN FETCH c.chapterTranslation as ct
WHERE bt.language = :lang
AND ct.language = :lang")
List<Book> findBooksByLanguage(Language lang);
}
See also How to filter child collection in JPQL query?
Side note: query derivation should only be used when the resulting method name is VERY similar to what you would have named the method anyway.
#Entity
#Table(name="cad_paciente")
#Loader(namedQuery = "selectInicial")
#NamedNativeQuery(
name="selectInicial",
query="select p.*, fu_obter_lista_convenios_pac(p.id) as ds_convenio from cad_paciente p where p.id = ?", resultClass = Paciente.class,
resultSetMapping = "sqlResult")
#SqlResultSetMapping(
name="sqlResult",
entities={
#EntityResult(entityClass = Paciente.class, fields={
#FieldResult(name="ds_convenio",column="ds_convenio")})})
public class Paciente {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
#Column(name="id_empresa")
private Integer id_empresa;
...
#Transient
#Column(name="ds_convenio")
private String ds_convenio;
public String getDs_convenio() {
return ds_convenio;
}
public void setDs_convenio(String ds_convenio) {
this.ds_convenio = ds_convenio;
}
My Controller method "pacientes.findAll()" won't return "ds_convenio" field with the correct value, listing "null" always in my JSON return.
What do I have to do?
Try removing the annotation #Transient and provide the column as below :
#Column(name="ds_convenio")
private String ds_convenio;
#org.springframework.data.annotation.Transient specifically states to the spring framework that the Object Mapper you are using should not include this value when converting from Java Object to JSON. Also, it means that the value is not to be persisted into the database, which means you could not query over it.
Or if you want to keep it as transient itself but does not require the value to be serialized then register the object mapper as below :
#Bean
public ObjectMapper includeTransientObjectMapper() {
Hibernate5Module hibernate5Module = new Hibernate5Module();
hibernate5Module.disable(Hibernate5Module.Feature.USE_TRANSIENT_ANNOTATION);
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(hibernate5Module);
return mapper;
}
Or in your case since you want the result of the #NamedNativeQuer in which you aliased ds_convenio, using #FieldResult might be required to get the desired result as follows :
#Entity
#Table(name="cad_paciente")
#Loader(namedQuery = "selectInicial")
#NamedNativeQuery(name="selectInicial", query="select p.*, fu_obter_lista_convenios_pac(p.id) as ds_convenio from cad_paciente p where p.id = ?", resultClass = Paciente.class)
#SqlResultSetMapping(name="Results",
entities={
#EntityResult(entityClass=com.acme.Order.class, fields={
#FieldResult(name="id", column="id"),
#FieldResult(name="id_empresa", column="id_empresa"),
........
})
public class Paciente {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotNull
#Column(name="id_empresa")
private Integer id_empresa;
...
#Transient
#Column(name="ds_convenio")
private String ds_convenio;
Read doc
i have over 1000 repository going to create and insert data,
headerDetailLinkn00001.java
#Entity // This tells Hibernate to make a table out of this class
#Table(name="HDL_HEADER_DETAIL_LINK_00001")
public class HeaderDetailLink00001{
#Id
#Column(name="HDL_ID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#Column(name="DRI_ID")
private Integer driId;
#Column(name="CSD_ID")
private Integer csdId;
...getter and setter
}
HeaderDetailLink00001Repository.java
public interface HeaderDetailLink00001Repository extends JpaRepository<HeaderDetailLink00001,Long>{
List<HeaderDetailLink00001> findTopByOrderByIdDesc();
}
controller.java
#GetMapping(path = "updateHeaderDetailTable")
public #ResponseBody int updateHeaderDetailTable(#RequestParam(value = "catNum", required = true) Integer catNum)
{
List<DailyHeaderResult> listBySymcatNum = DailyHeaderResultRepository.findBycatNum(catNum);
List<HeaderDetailLink00001> chdlList = new ArrayList<HeaderDetailLink00001>();
HeaderDetailLink00001 lastRecordOflinkTableId = HeaderDetailLink00001Repository.findTopByOrderByIdDesc().get(0);
this.setPreviousIndex(lastRecordOflinkTableId.getCsdId());
logger.info("sxxxxxxxxxxxxxId==="+lastRecordOflinkTableId.getCsdId()+" "+lastRecordOflinkTableId.getDriId());
...
i am going to create HeaderDetailLink00001, HeaderDetailLink00002... HeaderDetailLink10000...etc.
is it possible make HeaderDetailLink00001 and List generate dynamically.