jsf-2 - 如何从中的jsf页面获取Backing Bean的参数

Question

我的 xhtml:

<ui:repeat value="#{c.voices}" var="v"> 
    <h:form enctype="multipart/form-data">  
        <p:fileUpload fileUploadListener="#{AddNote.handleFileUpload}"
            converterMessage="converterMessage"
            mode="advanced"  
            update="messages"  
            sizeLimit="100000"                                                 
            allowTypes="/(\.|\/)(gif|jpe?g|png)$/">
        </p:fileUpload>  
        <p:growl id="messages" showDetail="true"/>                                     
    </h:form> 
</ui:repeat>

我的后台 bean :

 public void handleFileUpload(FileUploadEvent event) {
    //int v.id= here i need to know the v.id value from ui:repeater
    FacesMessage msg = new FacesMessage("Succesful", event.getFile().getFileName() + " is uploaded.");
    FacesContext.getCurrentInstance().addMessage(null, msg);
}

c.voices 是对象列表。每个对象都有属性 id .我需要知道 id 在 处理文件上传我怎样才能做到这一点？

Answer 1

我只想把 v.id在隐藏字段中:

你的 xhtml:

<ui:repeat value="#{c.voices}" var="v">
    <h:form enctype="multipart/form-data">
        <input type="hidden" name="vid" value="#{v.id}" />
        <p:fileUpload fileUploadListener="#{AddNote.handleFileUpload}"
            converterMessage="converterMessage"
            mode="advanced"
            update="messages"
            sizeLimit="100000"
            allowTypes="/(\.|\/)(gif|jpe?g|png)$/">
        </p:fileUpload>
        <p:growl id="messages" showDetail="true"/>
    </h:form> 
</ui:repeat>

然后使用 FacesContext 将其取回 bean 中:

您的 BackingBean:

public void handleFileUpload(FileUploadEvent event) {
    HttpServletRequest request = (HttpServletRequest) 
        FacesContext.getCurrentInstance().getExternalContext().getRequest();
    request.getParameter("vid"); // <= Here you are!
}

更新

正如评论中所述，每次迭代都有自己的 <h:form用它自己的 <input type="hidden" name="vid" .当文件上传时 handleFileUpload将使用封闭表单的数据触发，因此 vid参数将与正确的 #{v.id} 一起发送

更新 2

正如 BalusC 评论的，你最好得到 vid参数这样:

public void handleFileUpload(FileUploadEvent event) {
     FacesContext.getCurrentInstance().getExternalContext()
        .getRequestParameterMap().get("vid") // <= Here you are!
}