Question

我有一个测试.xhtml布局文件

. . .
<h:form rendered="#{departmentBean.editEmployee}">
  Employee name
  <h:inputText id="fullName" value="#{departmentBean.employee.fullName}" />
  <h:selectOneMenu label="Department" value="#{departmentBean.employee.department}" converter="departmentConverter">
    <f:selectItems value="#{departmentBean.departmentList}" var="department" 
                   itemLabel="#{department.name}" itemValue="#{department}" />
  </h:selectOneMenu>
  <h:commandButton value="Save" action="#{departmentBean.save()}" />
</h:form>
. . .

另外，我有两个Entity classess：Employee and Department：

@Entity
@Table(name = "departments")
public class Department implements Serializable {

  @Id
  @Column(name = "dep_pcode")
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private int id;

  @Column(name = "dep_name", nullable = false, length = 50)
  private String name;

  //. . . setters and getters
}

和

@Entity
@Table(name = "employee")
public class Employee implements Serializable {

  @Id
  @Column(name = "emp_pcode")
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private int id;

  @Column(name = "emp_fullname", nullable = false, length = 128)
  private String fullName;

  @ManyToOne
  @JoinColumn(name = "emp_depcode")
  private Department department;

  // . . . Setters and getters
}

所以我需要通过网络表单在一些具体的员工中设置部门。要从SelectOneMenu组件转换输入值，反之亦然，我使用自定义转换器：

@FacesConverter("departmentConverter")
public class DepartmentConverter implements Converter {

  @EJB
  DepartmentEJB ejb;

  @Override
  public Object getAsObject(FacesContext context, UIComponent component, String value) {
    Department result = null;
    try {
        int id = Integer.parseInt(value);
        result = ejb.get(id);
    } catch (Exception e) {
      throw new ConverterException("Can't convert into Department string value: " + value);
    }
    return result;
  }

  @Override
  public String getAsString(FacesContext context, UIComponent component, Object value) {
    if (value instanceof Department) {
      return ((Department) value).getId() + "";
    }
    throw new ConverterException("Can't use departmentConverter for " + value.getClass().getName());
  }
}

但是，提交表单时，我看到验证错误消息。

＆＃34;部门：验证错误：值无效＆＃34;。

我为Department类编写了自定义验证器

@FacesValidator("departmentValidator")
public class DepartmentValidator implements Validator {

  @Override
  public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
    if ((value instanceof Department)) {
      Department dep = (Department)value;
      if (dep.getId() == 0) {
        FacesMessage msg = new FacesMessage("Department's id = 0!",
                "Department validation failed.");
        msg.setSeverity(FacesMessage.SEVERITY_ERROR);
        throw new ValidatorException(msg);
      }
    } else {
        FacesMessage msg = new FacesMessage("Can't validate " + value.getClass().getName() + " as Department ",
                "Department validation failed.");
        msg.setSeverity(FacesMessage.SEVERITY_ERROR);
        throw new ValidatorException(msg);
    }
  }
}

我确信部门的验证值id实例。但我仍然得到验证错误，表示该值无效。

我可以在某处详细说明如何正确设置souch字段的值吗？我错过了什么？

感谢您的回答并浪费您的时间。最好的问候。

Answer 1

作为临时解决方案，我使用下面的内容：

在Employee类中创建@Transient字段（departmentCode）;
制作@PostLoad方法，该方法将链接的Department实例的id读入 departmentCode;
在.xhtml表单中，设置departmentCode的值而不是department;
在Managed Bean的save（）方法中，通过departmentCode值获取Department实例;
将获取的Department实例设置为Employee的department属性;

那么，任何人都知道更简单的方法吗？

如何从SelectOneMenu设置@ManyToOne注释字段？

1 个答案: