I have following dao method:
#Override
public List<AdminRole> findAll() {
Session session = sessionFactory.getCurrentSession();
Criteria criteria = session.createCriteria(AdminRole.class);
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
return criteria.list();
}
Actually I want to retrieve all entries from database.
Sometimes I see duplicates. This happens when I add user with AdminRole.
I have read that it is possible when I use EAGER fetch type and this should be fix adding following line:
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
But this doesn't help me.
my mapping:
#Entity
#Table(name = "terminal_admin_role")
public class AdminRole {
#Id
#Column(name = "role_id", nullable = false, unique = true)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_id")
#SequenceGenerator(name = "user_id", sequenceName = "user_id")
private Long adminId;
#Column(name = "role")
private String role;
public AdminRole(String role) {
this.role = role;
}
public AdminRole() {
}
// get set
#Override
public String toString(){
return role;
}
#Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof AdminRole)) {
return false;
}
AdminRole adminRole = (AdminRole) o;
if (!role.equals(adminRole.role)) {
return false;
}
return true;
}
#Override
public int hashCode() {
return role.hashCode();
}
}
and
#Entity
#Table(name = "terminal_admin")
public class TerminalAdmin {
#ManyToMany(fetch=FetchType.EAGER,cascade=CascadeType.ALL)
#JoinTable(name = "admin_role", joinColumns = {
#JoinColumn(name = "admin_id", nullable = false) },
inverseJoinColumns = { #JoinColumn(name = "role_id",
nullable = false) })
private Set<AdminRole> adminRoles;
//...
}
P.S.
I cannot switch fetch type.
I don't want to put this list into set.
There is no reason to use DISTINCT_ROOT_ENTITY or anything similar, all you need is:
session.createCriteria(AdminRole.class).list();
If you get duplicates, then you really have them in the database. Check the code which saves AdminRoles either directly or by cascading from other entities.
When cascading PERSIST/MERGE operations from other entities, make sure that the operation is cascaded to a persistent/detached AdminRole instance, not to a transient (new) one.
My money's on messing with hashCode/equals overrides and Hibernate proxies.
From EqualsandHashCode
However, once you close the Hibernate session, all bets are off. [...] Hence, if you keep collections of objects around between sessions, you will start to experience odd behavior (duplicate objects in collections, mainly).
First I'd use org.apache.commons.lang3 like so (it's obviously way too expensive for Hibernate entities but works ok w/ them and if it works that should validate my hunch):
import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;
#Override
public String toString() {
return ToStringBuilder.reflectionToString(this);
}
#Override
public int hashCode() {
return HashCodeBuilder.reflectionHashCode(this);
}
#Override
public boolean equals(Object other) {
return EqualsBuilder.reflectionEquals(this, other);
}
If this works you could go with a less expensive approach like so:
#Override
public int hashCode() {
HashCodeBuilder hcb = new HashCodeBuilder();
hcb.append(role);
return hcb.toHashCode();
}
#Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof AdminRole)) {
return false;
}
AdminRole that = (AdminRole) obj;
EqualsBuilder eb = new EqualsBuilder();
eb.append(role, that.role);
return eb.isEquals();
}
Related
I am trying to use the JPA Criteria API to filter the results and aggregate them using simple count, min, avg and max. I am using Spring Boot 2.7.8, so I am trying to use Interface-projections such that these aggregated results look the same as the simpler queries done automatically by the Spring repositories.
My domain entity (simplified for brevity) looks like this:
#Entity
#Table(name = "vehicle_stopped")
#IdClass(VehicleStopped.VehicleStoppedPK.class)
public class VehicleStopped implements Serializable {
#Id
#Column(name = "stopped_session_uuid", nullable = false)
private String stoppedSessionUuid;
#Id
#Column(name = "start_ts", nullable = false)
private OffsetDateTime startTs;
#Column(name = "end_ts", nullable = false)
private OffsetDateTime endTs;
#Column(name = "duration_seconds")
private Double durationSeconds;
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "zone_id")
private CameraZone cameraZone;
#Override
public VehicleStoppedPK getId() {
VehicleStopped.VehicleStoppedPK pk = new VehicleStopped.VehicleStoppedPK();
pk.setStartTs(this.getStartTs());
pk.setStoppedSessionUuid(this.getStoppedSessionUuid());
return pk;
}
public OffsetDateTime getEndTs() {
return endTs;
}
public void setEndTs(OffsetDateTime endTs) {
this.endTs = endTs;
}
public Double getDurationSeconds() {
return durationSeconds;
}
public void setDurationSeconds(Double durationSeconds) {
this.durationSeconds = durationSeconds;
}
public CameraZone getCameraZone() {
return cameraZone;
}
public void setCameraZone(CameraZone cameraZone) {
this.cameraZone = cameraZone;
}
public VehicleType getVehicleType() {
return vehicleType;
}
public void setVehicleType(VehicleType vehicleType) {
this.vehicleType = vehicleType;
}
public String getStoppedSessionUuid() {
return stoppedSessionUuid;
}
public void setStoppedSessionUuid(String stoppedSessionUuid) {
this.stoppedSessionUuid = stoppedSessionUuid;
}
//some details removed for brevity
#Override
public static class VehicleStoppedPK implements Serializable {
private OffsetDateTime startTs;
private String stoppedSessionUuid;
public VehicleStoppedPK() {
}
public OffsetDateTime getStartTs() {
return startTs;
}
public void setStartTs(OffsetDateTime startTs) {
this.startTs = startTs;
}
public String getStoppedSessionUuid() {
return stoppedSessionUuid;
}
public void setStoppedSessionUuid(String stoppedSessionUuid) {
this.stoppedSessionUuid = stoppedSessionUuid;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
VehicleStoppedPK that = (VehicleStoppedPK) o;
return Objects.equals(startTs, that.startTs) && Objects.equals(stoppedSessionUuid, that.stoppedSessionUuid);
}
#Override
public int hashCode() {
return Objects.hash(startTs, stoppedSessionUuid);
}
#Override
public String toString() {
return "VehicleStoppedPK{" +
"startTs=" + startTs +
", stoppedSessionUuid='" + stoppedSessionUuid + '\'' +
'}';
}
}
}
#Entity
#Table(name = "camera_zone")
public class CameraZone implements Serializable {
#Id
#SequenceGenerator(name = "camera_zone_id_seq", sequenceName = "camera_zone_id_seq", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "camera_zone_id_seq")
#Column(name = "id", updatable=false)
private Integer id;
#Column(name = "uuid", unique = true)
private String uuid;
#Column(name = "type")
private String type;
#Column(name = "name")
private String name;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUuid() {
return uuid;
}
public void setUuid(String uuid) {
this.uuid = uuid;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CameraZone that = (CameraZone) o;
return Objects.equals(id, that.id) && Objects.equals(uuid, that.uuid) && Objects.equals(camera, that.camera) && Objects.equals(type, that.type) && Objects.equals(name, that.name);
}
#Override
public int hashCode() {
return Objects.hash(id, uuid, camera, type, name);
}
}
The code that I have in my Repository implementation looks like this:
public class SpecificationVehicleStoppedRepositoryImpl
implements SpecificationVehicleStoppedRepository {
#Autowired private EntityManager em;
#Autowired ProjectionFactory projectionFactory;
#Override
public List<VehicleStoppedAggregate> getStoppedVehiclesCount(Specification<VehicleStopped> spec) {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Tuple> query = builder.createTupleQuery();
Root<VehicleStopped> root = query.from(VehicleStopped.class);
Predicate predicate = spec.toPredicate(root, query, builder);
if (predicate != null) {
query.where(predicate);
}
Path<Number> duration = root.get("durationSeconds");
Path<CameraZone> zone = root.get("cameraZone");
query
.multiselect(zone,
builder.count(root).alias("totalVehicles"),
builder.min(duration).alias("minDuration"),
builder.avg(duration).alias("avgDuration"),
builder.max(duration).alias("maxDuration"))
.groupBy(zone);
List<Tuple> rawResultList = em.createQuery(query).getResultList();
return project(rawResultList, VehicleStoppedAggregate.class);
}
private <P> List<P> project(List<Tuple> results, Class<P> projectionClass) {
return results.stream()
.map(tuple -> {
Map<String, Object> mappedResult = new HashMap<>(tuple.getElements().size());
for (TupleElement<?> element : tuple.getElements()) {
String name = element.getAlias();
mappedResult.put(name, tuple.get(name));
}
return projectionFactory.createProjection(projectionClass, mappedResult);
})
.collect(Collectors.toList());
}
}
The interface-based projection I am trying to populate (using SpelAwareProxyProjectionFactory) is this:
public interface VehicleStoppedAggregate {
CameraZone getCameraZone();
Integer getTotalVehicles();
Double getMinDuration();
Double getAvgDuration();
Double getMaxDuration();
}
The call to getStoppedVehiclesCount() fails with the following error:
ERROR: column "camerazone1_.id" must appear in the GROUP BY clause or be used in an aggregate function
This error is coming from the PostgreSQL database, and rightly so because the SQL hibernate generates is incorrect:
select
vehiclesto0_.zone_id as col_0_0_,
count(*) as col_1_0_,
min(vehiclesto0_.duration_seconds) as col_2_0_,
avg(vehiclesto0_.duration_seconds) as col_3_0_,
max(vehiclesto0_.duration_seconds) as col_4_0_,
camerazone1_.id as id1_2_,
camerazone1_.name as name2_2_,
camerazone1_.type as type3_2_,
camerazone1_.uuid as uuid4_2_
from
vehicle_stopped vehiclesto0_
inner join
camera_zone camerazone1_
on vehiclesto0_.zone_id=camerazone1_.id cross
where
vehiclesto0_.start_ts>=?
and vehiclesto0_.start_ts<=?
and 1=1
and 1=1
and 1=1
group by
vehiclesto0_.zone_id
It is not grouping by the other fields it is requesting from the joined table.
If I had to use a normal class, instead of a Tuple, it would work, but it would mean I would have to create a class with a huge constructor for all fields for Hibernate to populate it.
Somehow, when I use Interface-based projections with Spring's repositories rather than my criteriaquery, the same scenario works. They manage to populate the one-to-many relationships just fine.
Is there a way to fix this and make Hibernate ask for the right fields?
I am using Hibernate 5.6.14.Final (as bundled with Spring Boot 2.7.8).
I believe the "solution" is two create two "independent" query roots and join them together:
CriteriaBuilder builder = session.getCriteriaBuilder();
CriteriaQuery<Tuple> query = builder.createTupleQuery();
Root<VehicleStopped> root = query.from(VehicleStopped.class);
// instead of Path<CameraZone> zone = root.get("cameraZone")
Root<CameraZone> zone = query.from(CameraZone.class);
query.where(builder.equal(zone, root.get("cameraZone")));
Path<Number> duration = root.get("durationSeconds");
query
.multiselect(zone,
builder.count(root).alias("totalVehicles"),
builder.min(duration).alias("minDuration"),
builder.avg(duration).alias("avgDuration"),
builder.max(duration).alias("maxDuration"))
.groupBy(zone);
session.createQuery(query).getResultList();
In that case Hibernate 5 produces following SQL (which actually looks weird from my perspective due to missing columns in group by clause):
select
naturalidc1_.id as col_0_0_,
count(*) as col_1_0_,
min(naturalidc0_.duration_seconds) as col_2_0_,
avg(naturalidc0_.duration_seconds) as col_3_0_,
max(naturalidc0_.duration_seconds) as col_4_0_,
naturalidc1_.id as id1_0_,
naturalidc1_.name as name2_0_,
naturalidc1_.type as type3_0_,
naturalidc1_.uuid as uuid4_0_
from
vehicle_stopped naturalidc0_ cross
join
camera_zone naturalidc1_
where
naturalidc1_.id=naturalidc0_.zone_id
group by
naturalidc1_.id
FYI. Your initial query does work in Hibernate 6 and produced SQL does look more correct but still weird:
select
c1_0.id,
c1_0.name,
c1_0.type,
c1_0.uuid,
count(*),
min(v1_0.duration_seconds),
avg(v1_0.duration_seconds),
max(v1_0.duration_seconds)
from
vehicle_stopped v1_0
join
camera_zone c1_0
on c1_0.id=v1_0.zone_id
group by
1,
2,
3,
4
JDK 17
SpringBoot latest
JPA latest
MySQL 8.0.31
I am trying to implement a strategy that makes sure that both the name and the email address of each user are unique.
User entity:
#Entity
public class User {
......
#EmbeddedId
protected UserId id;
......
}
User id:
#Embeddable
public class UserId implements Serializable {
#Serial
private static final long serialVersionUID = -622156255674132106L;
#Column(name = "name", nullable = false)
protected String name = "";
#Column(name = "email", nullable = false)
protected String email = "";
public UserId(String name, String email) {
setName(name);
setEmail(email);
}
public UserId() {}
public void setName(String name) {
this.name = name;
}
public String getName() {
return Objects.requireNonNullElse(name, "");
}
public void setEmail(String email) {
this.email = email;
}
public String getEmail() {
return Objects.requireNonNullElse(email, "");
}
}
Now, by default, it is marked as a conflict only if userA.name == userB.name && userA.email == userB.email, which means there can be two users having the same email address as long as they do not share one single name. How to stop this from happening? What I expect is userA.name == userB.name || userA.email == userB.email.
I've tried overriding equals() and hashcode() in the following way.
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof UserId userId)) return false;
if (Objects.equals(name, userId.name)) return true;
return Objects.equals(email, userId.email);
}
#Override
public int hashCode() {
int result = name != null ? name.hashCode() : 0;
result = 31 * result + (email != null ? email.hashCode() : 0);
return result;
}
However, it does not work. Also, breakpoints inside these two functions are not reached.
==========Edited==========
I've solved the original problem. But when it comes to UsersRepository.existsById(), it's still considered not to exist if either of the two columns does not match. How can I fix it?
Whether you do this via annotations and schema generation, or just by creating / modifying the schema directly, the answer is the same.
You will need to create a single unique constraint in the database naming both columns, not two separate constraints.
If you want a schema generation annotation to do this, supply the #UniqueConstraint annotation to the #Table annotation, e.g.
#Table(uniqueConstraints = {
#UniqueConstraint(columnNames = {
"name", "email"
})
})
public class UserId implements Serializable {
#Serial
private static final long serialVersionUID = -622156255674132106L;
#Column(name = "name", nullable = false, unique=true)
protected String name = "";
#Column(name = "email", nullable = false, unique=true)
protected String email = "";
So,
I am trying to do a many to many implementation through Spring JPA.
I tried to do an embedded key implementation.
But I am getting this error
{
"message": "Internal server error",
"details": "Could not set field value [26] value by reflection : [class com.domain.configuredview.model.RelationshipViewPersonPK.personId] setter of com.domain.configuredview.model.RelationshipViewPersonPK.personId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [26] value by reflection : [class com.domain.configuredview.model.RelationshipViewPersonPK.personId] setter of com.domain.configuredview.model.RelationshipViewPersonPK.personId"
}
I tried searching through all the answers but couldn't fix this.
My classes are
import com.domain.person.model.Person;
import java.io.Serializable;
import javax.persistence.*;
import lombok.Data;
import lombok.NoArgsConstructor;
#Data
#NoArgsConstructor
#Entity
#Table(name = "relationship_view_person")
public class RelationshipViewPerson implements Serializable {
#EmbeddedId
private RelationshipViewPersonPK entryId;
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("viewId")
#JoinColumn(name = "view_id", nullable = false)
private ConfiguredView view;
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("personId")
#JoinColumn(name = "person_id", nullable = false)
private Person person;
public RelationshipViewPerson(ConfiguredView view, Person person) {
this.view = view;
this.person = person;
this.entryId = new RelationshipViewPersonPK(view.getId(), person.getWsGlobalId());
}
public void setEntryId(Long viewId, String personId) {
this.entryId.setViewId(viewId);
this.entryId.setPersonId(personId);
}
public void setView(ConfiguredView view) {
this.view = view;
}
public void setPerson(Person person) {
this.person = person;
}
public Person getPerson() {
return this.person;
}
public ConfiguredView getView() {
return this.view;
}
}
The relationship key is
import java.io.Serializable;
import javax.persistence.*;
import lombok.NoArgsConstructor;
#Embeddable
#NoArgsConstructor
public class RelationshipViewPersonPK implements Serializable {
#Column(name = "view_id")
private Long viewId;
#Column(name = "person_id")
private String personId;
public RelationshipViewPersonPK(Long viewId, String personId) {
this.viewId = viewId;
this.personId = personId;
}
// setters & getters
public void setViewId(Long viewId) {
this.viewId = viewId;
}
public void setPersonId(String personId) {
this.personId = personId;
}
public String getPersonId() {
return this.personId;
}
public Long getViewId() {
return this.viewId;
}
// Override equals and hashCode
#Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
RelationshipViewPersonPK that = (RelationshipViewPersonPK) o;
return this.viewId.equals(that.viewId) && this.personId.equals(that.personId);
}
#Override
public int hashCode() {
return this.viewId.hashCode() + this.personId.hashCode();
}
}
The ConfiguredView model has PK as id and Person model has field as wsGlobalId . The key on the Person table is not a PK.
I have the setters, getters, constructors, and pretty much everyting in place. Not sure whats happening with Hibernate here, it cannot find the getter or something? Not sure whats happening with this.
You should have a setter like below:
public void setEntryId(RelationshipViewPersonPK entryId) {
this.entryId.setViewId(entryId.getViewId());
this.entryId.setPersonId(entryId.getPersonId());
}
instead of (or in addition to) this:
public void setEntryId(Long viewId, String personId) {
this.entryId.setViewId(viewId);
this.entryId.setPersonId(personId);
}
I try to understand the purpose of #ShallowReference by creating a test case but I don't see any differences in the Javers changes. My application is a Spring Boot application with repository annotation.
I have a one to many bidirectional relationship between Customer and Project. The test case creates a Customer and a Project, then the project is added to the customer. I tried to run the test case with and without the #ShallowReference on the Set<Project> field to see the #ShallowReference behaviour. Then I query the changes but they are the same in both cases. I am looking for a test case to understand the #ShallowReference.
Test case:
#RunWith(SpringRunner.class)
#DataJpaTest
#Import({JaversSqlAutoConfiguration.class})
public class AuditTest {
#Autowired
private ProjectRepository projectRepository;
#Autowired
private Javers javers;
#Autowired
private CustomerRepository customerRepository;
#Test
public void testJavers() {
Customer customer = new Customer();
customer.setName("Stackoverflow");
customerRepository.save(customer);
Project project = new Project();
project.setName("Framework");
customer.addProject(project);
projectRepository.save(project);
QueryBuilder jqlQuery = QueryBuilder.anyDomainObject().withNewObjectChanges();
List<Change> changes = javers.findChanges(jqlQuery.build());
assertEquals(9, changes.size());
project.setName("Backend Framework");
projectRepository.save(project);
changes = javers.findChanges(jqlQuery.build());
assertEquals(10, changes.size());
}
}
Customer entity:
#Entity
#Table(name = "CUSTOMER")
#SQLDelete(sql = "UPDATE customer SET deleted = true WHERE id = ?")
#Where(clause = "deleted = false")
public class Customer extends AbstractEntity {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long id;
private String name;
#OneToMany(mappedBy = "customer")
// #ShallowReference
private Set<Project> projects = new HashSet<>();
// Getter/Setter
public void addProject(Project project) {
projects.add(project);
project.setCustomer(this);
}
public void removeProject(Project project) {
projects.remove(project);
project.setCustomer(null);
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Customer customer = (Customer) o;
return Objects.equals(id, customer.id);
}
#Override
public int hashCode() {
return Objects.hash(id);
}
}
Project entity:
#Entity
#Table(name = "PROJECT")
#SQLDelete(sql = "UPDATE project SET deleted = true WHERE id = ?")
#Where(clause = "deleted = false")
#EntityListeners(AuditingEntityListener.class)
public class Project extends AbstractEntity {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long id;
private String name;
#ManyToOne(fetch = FetchType.EAGER)
private Customer customer;
// Getter/Setter
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Project)) return false;
Project project = (Project) o;
return Objects.equals(id, project.id);
}
#Override
public int hashCode() {
return Objects.hash(id);
}
}
#ShallowReference doesn't work for collections. We have an open issue for that https://github.com/javers/javers/issues/528
PR's are welcome.
I'm working with Spring, hibernate and MySql but I have some problem with seralization of query result.
First in my entity I added #JsonManagedReference on Set structure (#OneToMany side) and #JsonBackReference on single object reference (#ManyToOne side) and it works but I wasn't be able to retrieve all needed information (for example #ManyToOne reference).
So i swapping #JsonBackReference on set structure and #JsonManagedReference on single object but I retrieve
No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: com.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst744_f["handler"])
I tried also with #JsonIgnore on Set structure but it doesn't work for the same issues.
This is my spring configuration
private Properties getHibernateProperties() {
Properties properties = new Properties();
properties.put(PROPERTY_NAME_HIBERNATE_DIALECT, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
// properties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));
properties.put(PROPERTY_NAME_HIBERNATE_FORMAT_SQL, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_FORMAT_SQL));
properties.put("hibernate.enable_lazy_load_no_trans",true);
return properties;
and this is part of one of my several entities:
/**
* Car generated by hbm2java
*/
#Entity
#Table(name = "car", catalog = "ATS")
public class Car implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer idCar;
#JsonManagedReference
private CarType carType;
#JsonManagedReference
private Fleet fleet;
private String id;
private int initialKm;
private String carChassis;
private String note;
#JsonBackReference
private Set<Acquisition> acquisitions = new HashSet<Acquisition>(0);
public Car() {
}
public Car(CarType carType, Fleet fleet, int initialKm, String carChassis) {
this.carType = carType;
this.fleet = fleet;
this.initialKm = initialKm;
this.carChassis = carChassis;
}
public Car(CarType carType, Fleet fleet, String id, int initialKm, String carChassis, String note,
Set<Acquisition> acquisitions) {
this.carType = carType;
this.fleet = fleet;
this.id = id;
this.initialKm = initialKm;
this.carChassis = carChassis;
this.note = note;
this.acquisitions = acquisitions;
}
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id_car", unique = true, nullable = false)
public Integer getIdCar() {
return this.idCar;
}
public void setIdCar(Integer idCar) {
this.idCar = idCar;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id_carType", nullable = false)
public CarType getCarType() {
return this.carType;
}
public void setCarType(CarType carType) {
this.carType = carType;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "id_fleet", nullable = false)
public Fleet getFleet() {
return this.fleet;
}
public void setFleet(Fleet fleet) {
this.fleet = fleet;
}
#Column(name = "id", length = 5)
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
#Column(name = "initialKm", nullable = false)
public int getInitialKm() {
return this.initialKm;
}
public void setInitialKm(int initialKm) {
this.initialKm = initialKm;
}
#Column(name = "carChassis", nullable = false, length = 20)
public String getCarChassis() {
return this.carChassis;
}
public void setCarChassis(String carChassis) {
this.carChassis = carChassis;
}
#Column(name = "note", length = 100)
public String getNote() {
return this.note;
}
public void setNote(String note) {
this.note = note;
}
#OneToMany(fetch = FetchType.LAZY, mappedBy = "car")
public Set<Acquisition> getAcquisitions() {
return this.acquisitions;
}
public void setAcquisitions(Set<Acquisition> acquisitions) {
this.acquisitions = acquisitions;
}
}
one method that uses the query:
#Override
#RequestMapping(value = { "/cars/{idFleet}"}, method = RequestMethod.GET)
public #ResponseBody TableUI getCars(#PathVariable int idFleet) {
TableUI ajaxCall=new TableUI();
try {
ajaxCall.setData(fleetAndCarService.findCarsByIdFleet(idFleet));
return ajaxCall;
} catch (QueryException e) {
ErrorResponse errorResponse= ErrorResponseBuilder.buildErrorResponse(e);
LOG.error("Threw exception in FleetAndCarControllerImpl::addCar :" + errorResponse.getStacktrace());
return ajaxCall;
}
}
two class for the query:
public interface DefRdiRepository extends JpaRepository<DefRdi, Integer>{
//#Query("SELECT CASE WHEN COUNT(c) > 0 THEN true ELSE false END FROM DefRdi c WHERE c.parName = ?1 AND c.description= ?2")
//Boolean existsByParNameAndDescription(String parName, String description);
//Query method of spring, I put findBy and then the key of research
DefRdi findByParNameAndDescription(String parName, String description);
}
public interface CarRepository extends JpaRepository<Car, Integer>, CarRepositoryCustom {
//Query method of spring, I put findBy and then the key of research
List<Car> findByFleetIdFleet(int idFleet);
}
Where is my error? I don't want Set object but only the single reference. The problem is only when I serialize. Thanks
UPDATE:
I use #JSonIgnore on all set collectionts and Eager instead lazy ad all works fine, but is there a way to retrieve all the information only when I want, for example having two different query?
So it doesn't work
#Override
#Transactional
public List<Car> findByFleetIdFleet(int idFleet) {
List<Car> carList= carRepository.findByFleetIdFleet(idFleet);
for (Car car:carList){
Hibernate.initialize(car.getCarType());
Hibernate.initialize(car.getFleet());
}
return carList;
// return carRepository.findByFleetIdFleet(idFleet);
}
All collections need to be fetched eagerly when loading them from data base, in order to get serialized by Spring. Make sure you fetch them eagerly (e.g. FetchMode.JOIN). You could also swap #JsonManagedReference from wanted fields with #JsonIgnore to black listed fields, Spring automatically serialises every field without annotation.
Update:
Changing the data repository to something like that should work, I am not sure it compiles, but I think you will get the point:
#EntityGraph(value = "some.entity.graph", type = EntityGraph.EntityGraphType.FETCH)
#Query(
value = "SELECT c FROM Car c INNER JOIN FETCH c.acquisitions WHERE c.id = :idFleet"
)
public interface CarRepository extends JpaRepository<Car, Integer>, CarRepositoryCustom {
//Query method of spring, I put findBy and then the key of research
List<Car> findByFleetIdFleet(int idFleet);
}
For more information look at this post and read the official documentation.
Workaround:
There seems to be a workaround, however fetching those collections eager like shown above should have a positive performance impact, since there is no need for loading proxies afterwards. Also no open transactions are needed at controller level.