Question

我在EXPERIENCE和COMPETENCE_LEVEL之间有一个ManyToMany关系。

我试过了：

PROFIL.java：

@Entity
@Table(name="profil")
public class Profil {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="id_profil")
    private Long idProfil;

    public Profil() {
        super();
    }

    public Long getIdProfil() {
        return idProfil;
    }

    public void setIdProfil(Long idProfil) {
        this.idProfil = idProfil;
    }

    @Override
    public String toString() {
        //[...]
    }

}

EXPERIENCE.java：

@Entity
@Table(name="experience")
public class Experience {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="id_experience")
    private Long idExperience;

    @ManyToOne
    @JoinColumn(name="id_profil")
    private Profil idProfil;

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "experience_competence_level", joinColumns = @JoinColumn(name = "id_experience", referencedColumnName = "id_experience"), inverseJoinColumns = @JoinColumn(name = "id_competence_level", referencedColumnName = "id_competence_level"))
    private List<CompetenceLevel> competenceLevels;

    public Experience() {
        super();
        idProfil = new Profil();
    }

    public Long getIdExperience() {
        return idExperience;
    }

    public void setIdExperience(Long idExperience) {
        this.idExperience = idExperience;
    }

    public Profil getIdProfil() {
        return idProfil;
    }

    public void setIdProfil(Profil idProfil) {
        this.idProfil = idProfil;
    }


    public List<CompetenceLevel> getCompetenceLevels() {
        return competenceLevels;
    }

    public void setCompetenceLevels(List<CompetenceLevel> competenceLevels) {
        this.competenceLevels = competenceLevels;
    }

    @Override
    public String toString() {
        // [...]
    }

}

COMPETENCE_LEVEL.java：

@Entity
@Table(name="competence_level")
public class CompetenceLevel {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="id_competence_level")
    private Long idCompetenceLevel;

    @OneToOne
    @JoinColumn(name="id_level")
    private Level level;

    @OneToOne
    @JoinColumn(name="id_profil")
    private Profil profil;

    @ManyToMany(mappedBy = "competenceLevels")
    private List<Experience> experiences;

    public CompetenceLevel() {
        super();
    }

    public Long getIdCompetenceLevel() {
        return idCompetenceLevel;
    }

    public void setIdCompetenceLevel(Long idCompetenceLevel) {
        this.idCompetenceLevel = idCompetenceLevel;
    }

    public Level getLevel() {
        return level;
    }

    public void setLevel(Level level) {
        this.level = level;
    }

    public Profil getProfil() {
        return profil;
    }

    public void setProfil(Profil profil) {
        this.profil = profil;
    }


    public List<Experience> getExperiences() {
        return experiences;
    }

    public void setExperiences(List<Experience> experiences) {
        this.experiences = experiences;
    }

    @Override
    public String toString() {
        // [...]
    }

}

当我启动一个试图获得我所有经验的网络服务时，我的执行速度很快，感觉就像是一个stackoverflow问题（我不是专家）：/。但是，如果我删除了CompetenceLevel类中的List，它就可以了。

我不明白为什么。我按照这个tuto：https://hellokoding.com/jpa-many-to-many-relationship-mapping-example-with-spring-boot-maven-and-mysql/

你知道吗？感谢。

Spring JPA，关于ManyToMany的stackoverflow

0 个答案: