Как извлечь данные из базы данных с помощью SelectOneMenu в Primefaces 3.2

Question

Я новичок в сетях 3.2. Мне нужно получить все имя отдела из базы данных в SelectOneMenu, но я этого не сделал!

<h:outputText value="Département : " /> 
<h:selectOneMenu value="#{departementBean.departement}" converter="#{departementConverter}"> 
    <f:selectItem itemLabel="Select One" itemValue="" noSelectionOption="true"/> 
    <f:selectItems var="dep" value="#{departementBean.list}" itemLabel="libelleDepartement" itemValue="#{departementBean.departement}" /> 
</h:selectOneMenu> 

Это DepartementConverter от этого Tuto How to populate options of h:selectOneMenu from database?

@ManagedBean(name = "departementConverter") 
@RequestScoped 
public class DepartementConverter implements Converter { 

    @ManagedProperty(value = "#{departementService}") 
    private DepartementService departementService; 

    @Override 
    public Object getAsObject(FacesContext context, UIComponent component, String value) { 

     Long id = Long.valueOf(value); 

     try { 
      return departementService.find(String.valueOf(id)); 
     } catch (Exception e) { 
      throw new ConverterException(new FacesMessage(String.format("Cannot convert %s to Departement", value)), e); 
     } 
    } 

    @Override 
    public String getAsString(FacesContext context, UIComponent component, Object value) { 
     Departement departement = (Departement) value; 
     return String.valueOf(departement.getIdDepartement()); 
    } 

    public DepartementService getDepartementService() { 
     return departementService; 
    } 

    public void setDepartementService(DepartementService departementService) { 
     this.departementService = departementService; 
    } 
} 

найти метод из DAOImpl выглядит следующим образом:

public Object find(String id) { 
    return this.getHibernateTemplate().find(id); 
} 

Но когда я запускаю проект, у меня есть это ОШИБКА:

INFO: Exception when handling error trying to reset the response. 
java.lang.ClassCastException: java.lang.String 
    at com.majustic.majemploi.converter.DepartementConverter.getAsString(DepartementConverter.java:43) 
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getFormattedValue(HtmlBasicRenderer.java:519) 
    at com.sun.faces.renderkit.html_basic.MenuRenderer.renderOption(MenuRenderer.java:534) 
    at com.sun.faces.renderkit.html_basic.MenuRenderer.renderOptions(MenuRenderer.java:792) 
    at com.sun.faces.renderkit.html_basic.MenuRenderer.renderSelect(MenuRenderer.java:844) 
    at com.sun.faces.renderkit.html_basic.MenuRenderer.encodeEnd(MenuRenderer.java:298) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:312) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:185) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:129) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) 
    at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:57) 
    at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:45) 
    at org.primefaces.component.panel.PanelRenderer.encodeContent(PanelRenderer.java:185) 
    at org.primefaces.component.panel.PanelRenderer.encodeMarkup(PanelRenderer.java:108) 
    at org.primefaces.component.panel.PanelRenderer.encodeEnd(PanelRenderer.java:55) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:312) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:185) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:129) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTab(AccordionPanelRenderer.java:218) 
    at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeTabs(AccordionPanelRenderer.java:147) 
    at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeMarkup(AccordionPanelRenderer.java:91) 
    at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeEnd(AccordionPanelRenderer.java:71) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1786) 
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:168) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1779) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1782) 
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:402) 
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:128) 
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:368) 
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109) 
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:101) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:79) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:55) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:36) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:178) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:189) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:106) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79) 
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:380) 
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:170) 
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:238) 
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:168) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:170) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:473) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:120) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:909) 
    at java.lang.Thread.run(Thread.java:662) 

Ошибка в этом Ligne: = значение

Département (департаментов) департаменте;

Пожалуйста, не могу исправить ошибку. Пожалуйста, помогите !!

Answer 1

Я думаю, проблема в том, что noSelectionOption.

Вы должны либо удалить ItemValue атрибут из этого параметра:

<f:selectItem itemLabel="Select one" 
     noSelectionOption="true"/> 

Или обработать itemValue="" случай в конверторе.

Answer 2

Вот общий GetAsString, которые вы можете использовать, если все объекты реализуют интерфейс с методом GetId() (который откровенно является хорошей идеей, если все ваши объекты имеют единый Id в качестве первичного ключа)

@Override 
public String getAsString(FacesContext facesContext, UIComponent component, Object object) { 
    if (object == null) { 
     return null; 
    } 
    if (object instanceof AbstractEntity) { 
     AbstractEntity e = (AbstractEntity) object; 
     return "" + e.getId(); 
    } 
    else 
     throw new IllegalArgumentException("object " + object + " is of type " + object.getClass().getName() + "; expected AbstractEntity"; 
}