'null Converter'的转换错误设置值"UserID"

Question

尝试从我的应用程序中的表中删除或编辑用户时出现转换错误.该值将从元数据传递listUser.xhmtl到deleteUser.xhtml页面.该值正在元数据中传递,但出于某种原因,在调用delete操作时,我得到了Conversion Error setting value "someemail@somedomain.com" for 'null Converter'.用户标识是String.

这是请求userDelete.xhmtl后的url:

http://localhost:8080/lavpWebApp/user/deleteUser.xhtml?user=someemail%40somedomain.com

这是userList.xhmtl简化:

<h:column>
                            <f:facet name="header">Edit</f:facet>
                            <h:link outcome="/user/editUser.xhtml" value="Edit User">
                                <f:param name="user" value="#{item.email}"/>
                            </h:link>                            
                        </h:column>

                        <h:column>
                            <f:facet name="header">Delete</f:facet>
                            <h:link outcome="/user/deleteUser.xhtml" value="Delete User">
                                <f:param name="user" value="#{item.email}"/>
                            </h:link>
                        </h:column>

这是userDelete.xhtml简化:

<f:metadata>
        <f:viewParam name="user" value="#{userController.user}" converter="#{userConverter}"/>
    </f:metadata>

    <h:body>
        Do you want to delete #{userController.user.name}?
        <h:form>
            <h:commandButton action="#{userController.deleteUser()}"
                             value="Delete"/>
            <h:commandButton action="#{userController.doCancelDeleteUser()}"
                             value ="Cancel"/>
        </h:form>
    </h:body>

这是Converter类:

@ManagedBean
@FacesConverter(value="userConverter")
public class UserConverter implements Converter{

    @EJB
    private UserSellerEJB userEjb;

    @Override
    public Object getAsObject(FacesContext context, UIComponent component, String value) {
        if (value == null || value.isEmpty())
        {
            return null;
        }
        if(!value.matches("\\d+"))
        {
            throw new ConverterException("The value is not a valid email: " + value);
        }

        String id = value.toString();
        return userEjb.findUserById(id);

    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, Object value) {
        if(value == null)
        {
            return null;
        }

        if(!(value instanceof UserSeller))
        {
            throw new ConverterException("The value is not a User: " + value);            
        }

        String id = ((UserSeller) value).getEmail();
        return (id != null) ? id.toString() : null;
    }

}

这是userController类的简化:

@Named
@RequestScoped
public class UserController{

    @EJB
    private UserSellerEJB userEJB;

    private UserSeller user = new UserSeller(); 
    private List<UserSeller> usersList = new ArrayList<UserSeller>();

    // ------------------------------------------------------------- Constructor
    public UserController() {
    }

    // -------------------------------------------------------- Business Methods

    public String doCreateUser()
    {
        user = userEJB.createSeller(user);
        usersList = userEJB.findAllSellers();
        return "listUser?faces-redirect=true";        
    }

        // update user

        public void PreRenderView()
        {
            if(user == null)
            {
                user = new UserSeller();
            }            
        }

        public String doUpdateUser()
        {
            if(user.getEmail() != null)
            {
                userEJB.updateSeller(user);
            }
            else
            {
                userEJB.createSeller(user);
            }

            return "listUser?faces-redirect=true";
        }

    public String deleteUser()
    {
        userEJB.deleteSeller(user);
        return "listUser?faces-redirect=true";
    }

    public String doCancelDeleteUser()
    {
        return "listUser?faces-redirect=true";
    }


    @PostConstruct
    public void init()
    {
        usersList = userEJB.findAllSellers();       
    }

Answer 1

该null converter异常消息表明,该转换器实例无法找到.由于您将转换器引用为托管bean converter="#{userConverter},因此只有在对其进行注释时才能找到它@javax.faces.bean.ManagedBean并且该类是否位于WAR中(因此不在EJB/EAR或其他地方!).

的@FacesConverter只有混乱首发-注释在此构造,实际上是多余的被使用.删除该注释.这些@EJB作品确实只在托管bean中.

如果真的徒劳(我无法解释原因),请尝试通过CDI管理它:用@ManagedBeanCDI @Named注释替换JSF 注释.您显然已经成功地通过CDI管理前端控制器bean.

与具体问题无关,转换器似乎设计为基于技术ID(数据库主键)而不是电子邮件地址进行转换.电子邮件地址永远不会匹配\d+(这是"仅数字"的正则表达式).确保您不会将电子邮件地址与ID混淆.