带Eclipselink的eclipselink尝试插入父表，

Question

我被困在以下问题上：

每次我尝试创建一个块时，eclipselink都会尝试插入一个condominio记录(应该为null )，当我在一个简单的java项目中运行相同的代码(没有spring)时，它可以正常工作，但是在web项目中，它一直试图插入“父”表中。

有什么原因可以解释为什么eclipselink试图强制建立双向关系呢？

实体

鸡奸

private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "idcondominio")
private Integer idcondominio;
@Basic(optional = false)
@Column(name = "nomecond")
private String nomecond;
@Column(name = "cnpjcond")
private Integer cnpjcond;
@OneToMany(mappedBy = "condominio")
private Collection<Bloco> blocoCollection;

布洛克

private static final long serialVersionUID = 1L;
@EmbeddedId
protected BlocoPK blocoPK;
@Basic(optional = false)
@Column(name = "nomebloco")
private String nomebloco;
@Column(name = "numero")
private String numero;
@JoinColumn(name = "condominio_idcondominio", referencedColumnName = "idcondominio", insertable = false, updatable = false)
@ManyToOne(optional = false)
private Condominio condominio;

==============================创建方法

public void create(Bloco bloco) throws PreexistingEntityException, Exception {
    if (bloco.getBlocoPK() == null) {
        bloco.setBlocoPK(new BlocoPK());
    }
    bloco.getBlocoPK().setCondominioIdcondominio(bloco.getCondominio().getIdcondominio());
    EntityManager em = null;
    try {
        em = getEntityManager();
        em.getTransaction().begin();
        Condominio condominio = bloco.getCondominio();
        if (condominio != null) {
            condominio = em.getReference(condominio.getClass(), condominio.getIdcondominio());
            bloco.setCondominio(condominio);
        }
        em.persist(bloco);
        if (condominio != null) {
            condominio.getBlocoCollection().add(bloco);
            condominio = em.merge(condominio);
        }
        em.getTransaction().commit();
    } catch (Exception ex) {
        if (findBloco(bloco.getBlocoPK()) != null) {
            throw new PreexistingEntityException("Bloco " + bloco + " already exists.", ex);
        }
        throw ex;
    } finally {
        if (em != null) {
            em.close();
        }
    }
}

=========================控制器方法

@RequestMapping(value = "cadbloco", method = RequestMethod.POST)
public String cadbloco(@ModelAttribute(value = "Bloco") Bloco bloco, @RequestParam("condid") int idcond ) throws Exception {

    BlocoJpaController jpa = new BlocoJpaController();
    Condominio c = new Condominio();
    c.setIdcondominio(idcond);
    jpa.create(bloco);

    return ("redirect:bloco.htm");

}

=====================

ype异常报告

消息请求处理失败；嵌套异常为javax.persistence.RollbackException: exception EclipseLink-4002：EclipseLink-4002

说明服务器遇到一个内部错误，无法满足此请求。

异常

org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常为javax.persistence.RollbackException: exception EclipseLink-4002：org.eclipse.persistence.exceptions.DatabaseException内部异常: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:列'nomecond‘不能为空错误代码: 1048调用:插入condominio (cnpjcond，nomecond)值(?，?)绑定org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) javax.servlet.http.HttpServlet.service(HttpServlet.java:648) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) javax.servlet.http.HttpServlet.service(HttpServlet.java:729) org.apache.tomcat.websocket绑定=> 2参数绑定查询: InsertObjectQuery(Entity.Condominio idcondominio=null )org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393) ( server.WsFilter.doFilter(WsFilter.java:52) )

Answer 1

这是正确的方法，我没有在块中设置condominio，所以当我尝试创建一个新的块时，它没有一个condominio。

我有时会犯这样的错误，但还是要感谢你的帮助。

==================================================================

@RequestMapping(value = "cadbloco"，method = RequestMethod.POST)公共字符串cadbloco(@ModelAttribute(value = " Bloco ") bloco，@RequestParam("condid") int idcond )引发异常{

    BlocoJpaController jpa = new BlocoJpaController();
    Condominio c = new Condominio();
    c.setIdcondominio(idcond);
    bloco.setCondominio(c);
    jpa.create(bloco);

    return ("redirect:bloco.htm");

}

Answer 2

异常显示"nomecond“值为null。因此，在控制器中，如果添加以下代码

C.setNomeCond(“某些值”)；

这应该能解决问题。