java - 冬眠します。多対多関連でリンクしない

Question

Candidate と Vacancy エンティティ (多対多の注釈) があります。

候補マッピング:

@ManyToMany(mappedBy = "candidates", fetch = FetchType.EAGER)
    @XmlTransient
    public Set<Vacancy> getVacancies() {
        return vacancies;
    }

空室マッピング:

@ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinTable(name = "vacancy_candidate", joinColumns = @JoinColumn(name = "vacancy_id"), inverseJoinColumns = @JoinColumn(name = "candidate_id"))
    public Set<Candidate> getCandidates() {
        return candidates;
    }

呼び出しコード:

@RequestMapping("/saveCandidate")
    public String saveCandidate(Model model,HttpServletRequest request,HttpResponse response
            ,@ModelAttribute("candidateFromRequest") Candidate candidateFromRequest
            ,@ModelAttribute("skillsIdList") Set<Skill> skills
           ,@ModelAttribute("vacanciesForCandidate") Set<Vacancy> vacanciesForCandidate
           ,RedirectAttributes redirectAttributes
            )
    {
        candidateFromRequest.setSkills(skills);
        candidateFromRequest.setVacancies(vacanciesForCandidate);//In debug I saw that here exist vacancy
        for(Vacancy vacancy:vacanciesForCandidate){
            vacancy.getCandidates().add(candidateFromRequest);
        }
        candidateService.update(candidateFromRequest);//invoke  session.update();
        redirectAttributes.addAttribute("message", "Submitted Correctly");
        redirectAttributes.addAttribute("id",candidateFromRequest.getId());
        return "redirect:loadCandidateById";
    } 

しかし、実際には、このトランザクションの後にデータベースにメモがありません。なぜ？