Java JSF2：如何从SelectOneMenu将值刷新到支持bean中？

我使用漂亮的面孔和JSF2

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

我有一个选择菜单来选择一个值。 然后，我想通过命令按钮将所选值传递到第二个表单，然后再传递到另一个页面。我不想在URL中看到参数

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

我不希望url是这样的：addpartpant.xhtml或addparticipant.xhtml？study_name=TEST或/Addparticpant/New/TEST

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

我只想要这样的URL/Addparticipant/New，但如果我这样做，我就无法检索好的参数值，我只检索bean中默认设置的参数值，而不是页面刷新值

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

更令人不安的是，当我更改页面中的默认值时，会出现一个按钮。它可以工作，但看起来参数的bean值没有影响，仍然保持默认值

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

我该怎么做呢？谢谢你的帮助。我试着在ajax调用中设置bean中的值param，但实际上不起作用

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

/*表单，当您更改 选择OneMenu可将值作为参数添加到第二个表单中*/

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

/*第二种形式是从ajax注入要传递的参数 从下表中的移动事件调用*/

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

PrettyFaces配置文件：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

页面结果addParticipant.xhtml:

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

Prettyfaces模式来执行导航。因此，您可以在

h:commandButton

操作方法中调用托管bean方法，而不是返回导航结果本身并将参数放入：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

在托管bean中：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

公共字符串actionGoToadStudent（）{
FacesContext.getCurrentInstance（）.getExternalContext（）.getFlash（）.put（“参数1”，研究名称）；
返回“pretty:participant”；//或只返回“/addParticipant.xhtml”，Prettyfaces将转换为pretty url
}

之后，您可以从目标托管bean中检索

param1

。这是用于使用隐藏参数的

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

无论何时您想要使用标准的visible GET参数，您都会发现这些参数非常有用。使用GET参数需要将它们与GET请求一起发送，因此您的目标页面必须使用

捕捉它们，并将它们保存在目标托管bean属性中。在这里，您可以参考我的：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

源页面：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

目的地页面：

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

---

正如您之前所说的，另一个解决方案可能是简单地将forward与JSF导航结合使用。参数被隐藏在第一个导航url页面上（例如，我们可以说/Home）。但是好吧，您将不会有/Addparticpant/New/TEST样式

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

PrettyFaces提供的POST-REDIRECT-GET的优点是什么？而且f:param在使用PrettyFaces时实际上是毫无意义的，因为POST…除非您使用GET（这意味着您不使用PrettyFaces）&您将参数放在URL中。我将阅读您的链接，因为事实上，根据作用域、Post/get操作和位置（在JSF页面/backingbean中）检索参数时遇到了一些问题

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

替代解决方案：  

    <navigation-rule>
       <from-view-id>/home.xhtml</from-view-id> 
       <navigation-case>
          <from-outcome>participant</from-outcome>
          <to-view-id>/addParticipant.xhtml</to-view-id>
       </navigation-case>
    </navigation-rule>


    /*I use viewparam but if I don't use it it's working too, I clearly don't understand what viewparam is used for  */

    <f:metadata>
          <f:viewParam name="study_name" value="#{home.study_name}" required="true"/>
     </f:metadata>

   /* What is the best way to retrieve information? Then how i load param in a backing bean who this destination page ? */ 
   <h:outputFormat value="Hello,{0},{1},">
                <f:param value="#{home.study_name}" />
                <f:param value="#{param.studynameItem}" />
    </h:outputFormat>

/home.xhtml
参与者
/addParticipant.xhtml
/*我使用viewparam，但如果我不使用它，它也会工作，我显然不理解viewparam的用途*/
/*检索信息的最佳方式是什么？那么我如何在一个支持bean中加载param，这个目标页面是谁？*/

您基本上有两种选择。一种是不执行

重定向

，因此浏览器中的url不会更改。第二种方法是使用flash scope或类似工具，以某种方式将参数值从一个视图保留到另一个视图？不事实上，我必须让漂亮的面孔失望，并使用类似thaht的action=“addParticipant”，我不知道如何检索参数，是否必须在目标页面中使用#{home.study_name}或#{thenameofstudy}。（'home'是发件人页面中的bean）我提出了一个没有漂亮面孔的另一个解决方案，并向其他人提出了与主题相关的上述问题。谢谢.getFlash（）抛出一个错误-java.lang.NoSuchMethodError:javax.servlet.http.Cookie.IshtPonly（）。。。我从一个登录页面（Spring Security）来到my home.xhtml（会话范围，也许我会改为查看范围，我实际上正在阅读有关范围和如何使用范围的资料），然后我想去addParticipant.xhtml在我的数据库中添加一些东西（请求范围）。这是全局的想法。这取决于您的servlet api版本，您使用的是哪台服务器？此版本可以吗？Mojara是2.2.0。我还没有解决使用flash scope时的错误。在目标页面中使用

/Participant/New/#{Participant.study_name}

（注意，我在这里使用的是目标bean），并且仅将

/Participant/New/

与

f:viewParam

结合使用是多余的。这意味着，他们做同样的事情。看，与PrettyFaces的团队领导讨论。但是，我强烈建议您使用第二种方法，即不要在url映射中直接包含EL表达式。无论如何，很高兴看到它帮助解决了这个问题！你实际上是在混合param的概念。假设您有一个托管bean绑定到您的主页，另一个绑定到您的添加学生页面，

/addParticipant.xhtml

不必访问

主页

bean，决不。这就是视图参数的用途。还请记住，实际上，PrettyFaces用于执行GET请求，即获取内容页。我会更新我的答案给你一些提示。另外，POST-REDIRECT-GET也有它的优点，因为它是一种干净、清晰的模式，并且