如何在JSF 2中获得当前结果

Question

我想从导航规则中获得结果值到请求范围的JSF 2 bean.我怎样才能做到这一点？

例如,当我按下a <h:link outcome="contacts">并最终进入联系人页面时,我希望得到"contacts"与导航菜单相关联的支持bean 的结果.

faces-config.xml中

<navigation-rule>
    ...
    <navigation-case>
        <from-outcome>contacts</from-outcome>
        <to-view-id>/pages/contacts.xhtml</to-view-id>
    </navigation-case>
    ...
</navigation-rule>

Answer 1

在JSF,AFAIK中,只有ConfigurableNavigationHandler会有这些信息.因此,创建一个自定义项ConfigurableNavigationHandler,将结果存储在请求参数中,供您在目标页面中使用.

1. 自定义导航处理程序

   public class NavigationHandlerTest extends ConfigurableNavigationHandler {
   
   private NavigationHandlerTest concreteHandler;
   
      public NavigationHandlerTest(NavigationHandler concreteHandler) {
       this.concreteHandler = concreteHandler;
      }
   
   
   @Override
      public void handleNavigation(FacesContext context, String fromAction, String    outcome){
       //Grab a hold of the request parameter part and save the outcome in it for
       //later retrieval
        FacesContext context = FacesContext.getCurrentInstance();
        ExternalContext ctx = context.getExternalContext();
        ctx.getRequestMap().put("currentOutcome", outcome);
   
       //resume normal navigation
        concreteHandler.handleNavigation(context, fromAction, outcome);   
       }   
     } 
   

2. 在faces-config.xml中配置处理程序

     <application>
        <navigation-handler>com.foo.bar.NavigationHandlerTest</navigation-handler>
     </application>
   

3. 检索目标bean

     @ManagedProperty(value="#{param.currentOutcome}")
     String outcome;
     //getter and setter