class org.hibernate.mapping.JoinedSubclass cannot be cast to class org.hibernate.mapping.RootClass

Question

I'm in the process of creating a CRM for my final training project. I have this error which appears when I run the application and I block completely.

My research says it's related to IDs between parents, children, etc. but I'm lost.

My parent class is "Personn" :

package fr.epsi.poec24.mspr.epsimspr.entities;

import jakarta.persistence.*;

import java.io.Serializable;

@Entity
@Table(name = "personnes")
@Inheritance(strategy = InheritanceType.JOINED)
public class Personne implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id_personne")
    private int id_personne;

    @Column(name = "prenom")
    private String prenom;

    @Column(name = "nom")
    private String nom;

    @Column(name = "numero_rue")
    private String numero_rue;

    @Column(name = "ville")
    private String ville;

    @Column(name = "code_postal")
    private int code_postal;

    @Column(name = "email")
    private String email;

    @Column(name = "telephone")
    private String telephone;

    @Column(name = "type_personne")
    private String type_personne;  // Ajout du champ pour indiquer le type de personne

    @OneToOne(mappedBy = "personne", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private Client client;

    @OneToOne(mappedBy = "personne", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private Employe employe;

    // Constructeurs
    public Personne() {
    }

    public Personne(String prenom, String nom) {
        this.prenom = prenom;
        this.nom = nom;
    }

    // Getters and setters
    public int getId() {
        return id_personne;
    }

    public void setId(int id) {
        this.id_personne = id;
    }

    public String getPrenom() {
        return prenom;
    }

    public void setPrenom(String prenom) {
        this.prenom = prenom;
    }

    public String getNom() {
        return nom;
    }

    public void setNom(String nom) {
        this.nom = nom;
    }

    public String getNumero_rue() {
        return numero_rue;
    }

    public void setNumero_rue(String numero_rue) {
        this.numero_rue = numero_rue;
    }

    public String getVille() {
        return ville;
    }

    public void setVille(String ville) {
        this.ville = ville;
    }

    public int getCode_postal() {
        return code_postal;
    }

    public void setCode_postal(int code_postal) {
        this.code_postal = code_postal;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getTelephone() {
        return telephone;
    }

    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }

    public String getType_personne() {
        return type_personne;
    }

    public void setType_personne(String type_personne) {
        this.type_personne = type_personne;
    }

    public Client getClient() {
        return client;
    }

    public void setClient(Client client) {
        this.client = client;
    }

    public Employe getEmploye() {
        return employe;
    }

    public void setEmploye(Employe employe) {
        this.employe = employe;
    }
}

I have two child classes :

package fr.epsi.poec24.mspr.epsimspr.entities;

import com.fasterxml.jackson.annotation.JsonAnyGetter;
import jakarta.persistence.*;

import java.io.Serializable;
import java.util.List;

@Entity
@Table(name = "clients", schema = "mspr-crm-acme")
public class Client extends Personne implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
//    @Column(name = "id")
    private int id_client;

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "id_personne",
            referencedColumnName = "id")
    private Personne personne;

    @Column(name = "type_personne")
    private String type_personne;

    @OneToMany(mappedBy = "client", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private List<Commande> commandes;

    // Constructors
    public Client() {
    }

    public Client(int id, String nom, String prenom) {
        super(nom, prenom);
        this.id_client = id;
    }

    // Getters and setters
    public int getId() {
        return id_client;
    }

    public void setId(int id) {
        this.id_client = id;
    }

    public String getType_personne() {
        return type_personne;
    }

    public void setType_personne(String type_personne) {
        this.type_personne = type_personne;
    }
}

package fr.epsi.poec24.mspr.epsimspr.entities;

import jakarta.persistence.*;

import java.io.Serializable;

@Entity
@Table(name = "employes")
public class Employe extends Personne implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id_employe;

    @Column(name = "type_personne")
    private String type_personne;

    @OneToOne (fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "id_personne", referencedColumnName = "id")
    private Personne personne;

    // Constructors
    public Employe() {
    }

    public Employe(String nom, String prenom) {
        super(nom, prenom);
    }

    // Getters and setters
    public int getId() {
        return id_employe;
    }

    public void setId(int id) {
        this.id_employe = id;
    }

    public String getType_personne() {
        return type_personne;
    }

    public void setType_personne(String type_personne) {
        this.type_personne = type_personne;
    }
}

Here are the extracts from my script, if that's any help:

[...]

CREATE TABLE IF NOT EXISTS personnes (
  `id_personne` bigint NOT NULL AUTO_INCREMENT,
  `prenom` varchar(50) DEFAULT NULL,
  `nom` varchar(50) DEFAULT NULL,
  `numero_rue` varchar(10) DEFAULT NULL,
  `rue` varchar(255) DEFAULT NULL,
  `ville` varchar(255) DEFAULT NULL,
  `code_postal` mediumint(10) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `telephone` varchar(20) DEFAULT NULL,
  `type_personne` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id_personne`)
);

[...]

CREATE TABLE IF NOT EXISTS clients (
  `id_client` bigint NOT NULL AUTO_INCREMENT,
  `id_personne` bigint NOT NULL,
  `type_personne` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id_client`),
  FOREIGN KEY (`id_personne`) REFERENCES personnes(`id_personne`)
);

CREATE TABLE IF NOT EXISTS employes (
  `id_employe` bigint NOT NULL AUTO_INCREMENT,
  `login` VARCHAR(50) NOT NULL UNIQUE,
  `mot_de_passe` VARCHAR(255) NOT NULL,
  `id_personne` bigint NOT NULL,
  `type_personne` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id_employe`),
  FOREIGN KEY (`id_personne`) REFERENCES personnes(`id_personne`)
);

Thanks you so much !

Here's the error message:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: class org.hibernate.mapping.JoinedSubclass cannot be cast to class org.hibernate.mapping.RootClass (org.hibernate.mapping.JoinedSubclass and org.hibernate.mapping.RootClass are in unnamed module of loader 'app')
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1773) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:599) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1231) ~[spring-context-6.1.3.jar:6.1.3]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:949) ~[spring-context-6.1.3.jar:6.1.3]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:624) ~[spring-context-6.1.3.jar:6.1.3]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.2.2.jar:3.2.2]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-3.2.2.jar:3.2.2]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[spring-boot-3.2.2.jar:3.2.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:334) ~[spring-boot-3.2.2.jar:3.2.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1354) ~[spring-boot-3.2.2.jar:3.2.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-3.2.2.jar:3.2.2]
    at fr.epsi.poec24.mspr.epsimspr.EpsiMsprApplication.main(EpsiMsprApplication.java:26) ~[classes/:na]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:50) ~[spring-boot-devtools-3.2.2.jar:3.2.2]
Caused by: java.lang.ClassCastException: class org.hibernate.mapping.JoinedSubclass cannot be cast to class org.hibernate.mapping.RootClass (org.hibernate.mapping.JoinedSubclass and org.hibernate.mapping.RootClass are in unnamed module of loader 'app')
    at org.hibernate.boot.model.internal.PropertyBinder.bind(PropertyBinder.java:306) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.makePropertyValueAndBind(PropertyBinder.java:297) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.createBasicBinder(PropertyBinder.java:1169) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.bindBasic(PropertyBinder.java:1071) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.bindProperty(PropertyBinder.java:890) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.buildProperty(PropertyBinder.java:788) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.PropertyBinder.processElementAnnotations(PropertyBinder.java:709) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.EntityBinder.processIdPropertiesIfNotAlready(EntityBinder.java:1026) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.EntityBinder.handleIdentifier(EntityBinder.java:354) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.EntityBinder.bindEntityClass(EntityBinder.java:234) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.internal.AnnotationBinder.bindClass(AnnotationBinder.java:423) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:256) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:279) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:322) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1432) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1503) ~[hibernate-core-6.4.1.Final.jar:6.4.1.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:75) ~[spring-orm-6.1.3.jar:6.1.3]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:376) ~[spring-orm-6.1.3.jar:6.1.3]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-6.1.3.jar:6.1.3]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-6.1.3.jar:6.1.3]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:352) ~[spring-orm-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1820) ~[spring-beans-6.1.3.jar:6.1.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1769) ~[spring-beans-6.1.3.jar:6.1.3]
    ... 19 common frames omitted