Dupliquer lors du tri à l'aide de Pageable

Controller:

@Entity
@Data
@Table(name = "job")
public class Job {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(unique = true, nullable = false, columnDefinition = "serial")
    private Long id;

    @Column(name = "name", nullable = false)
    private String name;

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

    @ManyToMany(fetch = FetchType.EAGER, targetEntity = Competence.class)
    @JoinTable(name = "job_has_competence",
            joinColumns = { @JoinColumn(name = "job_id", referencedColumnName = "id")},
            inverseJoinColumns = { @JoinColumn(name = "competence_id", referencedColumnName = "id")}
    )
    private Set<Competence> competences = new HashSet<>();

    @ManyToMany(fetch = FetchType.EAGER, targetEntity = Material.class)
    @JoinTable(name = "job_has_material",
            joinColumns = { @JoinColumn(name = "job_id", referencedColumnName = "id")},
            inverseJoinColumns = { @JoinColumn(name = "material_id", referencedColumnName = "id")}
    )
    private Set<Material> materials = new HashSet<>();

    @ManyToMany(fetch = FetchType.EAGER, targetEntity = Mechanism.class)
    @JoinTable(name = "job_has_mechanism",
            joinColumns = { @JoinColumn(name = "job_id", referencedColumnName = "id")},
            inverseJoinColumns = { @JoinColumn(name = "mechanism_id", referencedColumnName = "id")}
    )
    private Set<Mechanism> mechanisms = new HashSet<>();

    @Column(name = "create_time", nullable = false, updatable = false)
    @JsonIgnore
    private Date createTime = new Date();

    @Column(name = "update_time", nullable = false)
    @JsonIgnore
    private Date updateTime = new Date();

    @PreUpdate
    @PrePersist
    public void onCreateOnUpdate() {
        updateTime = new Date();
    }

}

Service:

public Page<com.bitweb.syda.data.entity.service.Service> getServicesList(ServiceListRequest request, Pageable pageable) {
        Specification<com.bitweb.syda.data.entity.service.Service> spec = where(null);

        if (request.getSearch() != null) spec = spec.and(search(request.getSearch()));
        if (request.getName() != null) spec = spec.and(name(request.getName()));
        if (request.getJobs() != null) spec = spec.and(hasJobs(request.getJobs()));
        if (request.getNeedsPatrol() != null) spec = spec.and(needsPatrol(request.getNeedsPatrol()));

        return serviceRepository.findAll(spec, pageable);
    }

Un service peut avoir plusieurs tâches.

Ce que j'essaie de faire, c'est de trier ASC / DESC par le premier élément des travaux, mais actuellement, si un service a, disons 4 travaux, après le tri en utilisant:

localhost:8080/serviceslist?sort=jobs&sortDir=asc

il me donne le service 4 fois, mais j'ai besoin qu'il soit distinct. Est-ce que pageable a un moyen de supprimer les doublons et de résoudre mon problème de tri?

Fonction ServiceService getServicesList:

@Entity
@Data
@Table(name = "service")
public class Service {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(unique = true, nullable = false, columnDefinition = "serial")
    private Long id;

    @Column(name = "name", nullable = false)
    private String name;

    @Column(name = "price", nullable = false)
    private float price;

    @Column(name = "season", nullable = false, columnDefinition = "season_enum")
    @Enumerated(EnumType.STRING)
    @Type(type = "pgsql_enum")
    private SeasonEnum season;

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

    @Column(name = "needs_patrol")
    private boolean needsPatrol;

    @Column(name = "image_required")
    private boolean imageRequired;

    @ManyToOne
    @JoinColumn(name = "color_id", nullable = false)
    private Color color;

    @Column(name = "start_date")
    private Date startDate;

    @Column(name = "end_date")
    private Date endDate;

    @OneToMany(mappedBy = "service")
    @JsonIgnore
    private List<ObjectService> objectServices = new ArrayList<>();

    @ManyToMany(fetch = FetchType.EAGER, targetEntity = Job.class)
    @JoinTable(name = "service_has_job",
            joinColumns = { @JoinColumn(name = "service_id", referencedColumnName = "id")},
            inverseJoinColumns = { @JoinColumn(name = "job_id", referencedColumnName = "id")}
    )
    private Set<Job> jobs = new HashSet<>();

    @Column(name = "create_time", nullable = false, updatable = false)
    @JsonIgnore
    private Date createTime = new Date();

    @Column(name = "update_time", nullable = false)
    @JsonIgnore
    private Date updateTime = new Date();

    @PreUpdate
    @PrePersist
    public void onCreateOnUpdate() {
        updateTime = new Date();
    }

    public enum SeasonEnum {
        winter, summer, all_year
    }
}

Le tri par nom et par truc fonctionne bien, juste le la partie jobs est cassée: /

Edit 21.04.2019: Je suis désolé si je n'étais pas vraiment clair avant. Le résultat idéal serait de trier par ordre alphabétique du premier travail, puisque les travaux sont dans l'ordre où ils sont terminés. Est-ce possible d'une manière ou d'une autre? Merci d'avance!

Entité d'emploi:

@RequestMapping(path = "/serviceslist", method = RequestMethod.GET)
    public Page<ServiceResponse> getServicesList(
            @RequestParam(defaultValue = "0") Integer page,
            @RequestParam(defaultValue = "10") Integer size,
            @RequestParam(required = false) String search,
            @RequestParam(required = false) String name,
            @RequestParam(required = false) String jobs,
            @RequestParam(required = false) Boolean needsPatrol,
            @RequestParam(defaultValue = "createTime") String sort,
            @RequestParam(defaultValue = "asc") String sortDir
    ) {

        ServiceListRequest request = new ServiceListRequest(search, name, jobs, needsPatrol);

        Sort.Direction direction;

        if (sortDir.equals("asc")) {
            direction = Sort.Direction.ASC;
        } else {
            direction = Sort.Direction.DESC;
        }

        return serviceService.getServicesList(request, of(page, size, direction, sort))
                .map(ServiceResponse::new);
    }