Mapeamento ManyToMany com colunas adicionais na JPA

Estudante.java

@Entity
@Table(name = "estudantes")
public class Estudante {
  
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;
  private String nome;
  //outros atributos...
  
  @OneToMany(mappedBy = "estudante", cascade = CascadeType.ALL, orphanRemoval = true)
  private List<Matricula> matriculas = new ArrayList<>();
  
  public void registrarMatricula(Turma turma) {
    Matricula matricula = new Matricula(this, turma);
    matriculas.add(matricula);
    turma.getMatriculas().add(matricula);
  }
  
  public void removerMatricula(Turma turma) {
    for (Iterator<Matricula> iterator = matriculas.iterator(); iterator.hasNext();) {
      Matricula matricula = iterator.next();
      if (matricula.getEstudante().equals(this) && matricula.getTurma().equals(turma)) {
        iterator.remove();
        matricula.getTurma().getMatriculas().remove(matricula);
        matricula.setEstudante(null);
        matricula.setTurma(null);
      }
    }
  }
  
  //getters, setters, equals, hashCode, etc.
}

Matricula.java

@Entity
@Table(name = "matriculas")
public class Matricula {
 
  @EmbeddedId
  private MatriculaId id;

  @ManyToOne(fetch = FetchType.LAZY)
  @MapsId("estudanteId")
  private Estudante estudante;

  @ManyToOne(fetch = FetchType.LAZY)
  @MapsId("turmaId")
  private Turma turma;

  private LocalDateTime data = LocalDateTime.now();

  //outros atributos

  private Matricula() {}

  public Matricula(Estudante estudante, Turma turma) {
      this.estudante = estudante;
      this.turma = turma;
      this.id = new MatriculaId(estudante.getId(), turma.getId());
  }

  //getters, setters, equals, hashCode, etc.
}

MatriculaId.java

@Embeddable
public class MatriculaId implements Serializable {
 
    @Column(name = "estudante_id")
    private Long estudanteId;
 
    @Column(name = "turma_id")
    private Long turmaId;
 
    private MatriculaId() {}
 
    public MatriculaId(Long estudanteId, Long turmaId) {
        this.estudanteId = estudanteId;
        this.turmaId = turmaId;
    }
 
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
 
        if (o == null || getClass() != o.getClass())
            return false;
 
        MatriculaId that = (MatriculaId) o;
        return Objects.equals(estudanteId, that.estudanteId) &&
               Objects.equals(turmaId, that.turmaId);
    }
 
    @Override
    public int hashCode() {
        return Objects.hash(estudanteId, turmaId);
    }
  
    //getters, setters, etc.
}

Turma.java

@Entity
@Table(name = "turmas")
public class Turma {
  
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;
  private String codigo;
  //outros atributos...
  
  @OneToMany(mappedBy = "turma", cascade = CascadeType.ALL, orphanRemoval = true)
  private List<Matricula> matriculas = new ArrayList<>();
  
  //getters, setters, equals, hashCode, etc.
}