无法使用 JPA 创建无状态 EJB

Could not create stateless EJB with JPA

我正在尝试使用 EJB 和 JPA 将一些数据插入到数据库中。当我执行代码时,出现 serverError: class javax.faces.el.EvaluationException javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB 错误。这是我的代码。我通过改变各种东西尝试了很多。发生了什么错误?我认为我的实体管理器初始化有一些错误

 DesignationEntity de = new DesignationEntity();
        de.setDesignationName(this.designationName);
        de.setDesignationDescription(this.designationDescription);
        ds.addDesignationDb(de);

EJB 服务class

@Stateless
@LocalBean
public class DesignationService {

    @PersistenceUnit(unitName = "ecs2complainmanager")
    private EntityManager em;

    public DesignationService() {
    }



    public void addDesignationDb(DesignationEntity de){
        em.persist(de);
    }
}


Entity class

@Entity
public class DesignationEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private Integer designationId;

    private String designationName;

    private String designationDescription;

    @OneToOne(mappedBy = "designationId")
    private UserEntity user;

    public Long getId() {
        return id;
    }

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

    public Integer getDesignationId() {
        return designationId;
    }

    public void setDesignationId(Integer designationId) {
        this.designationId = designationId;
    }

    public String getDesignationName() {
        return designationName;
    }

    public void setDesignationName(String designationName) {
        this.designationName = designationName;
    }

    public String getDesignationDescription() {
        return designationDescription;
    }

    public void setDesignationDescription(String designationDescription) {
        this.designationDescription = designationDescription;
    }

    public UserEntity getUser() {
        return user;
    }

    public void setUser(UserEntity user) {
        this.user = user;
    }



}

@PersistenceUnit 是原因。我改成@PersistenceContext