如何从< ui:repeat>中的jsf页面获取参数到BackingBean [英] How to get parametrs to BackingBean from jsf page in <ui:repeat>

问题描述

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BackingBean:

My BackingBean:

 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 handelFileUpload 中的 id ，该如何实现?

c.voices is list of objects. Every object have attribute id. I need to know the id in handelFileUpload how can I achieve that?

推荐答案

我只是将v.id放在隐藏字段中:

I would simply put v.id in an hidden field :

您的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将其重新放入Bean中:

And then get it back in the bean using FacesContext :

您的BackingBean:

Your BackingBean:

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

更新

如注释中所述，每个迭代将拥有自己的<h:form和自己的<input type="hidden" name="vid".上传文件后，handleFileUpload会被附带表格的数据触发，因此vid参数将以正确的#{v.id}

As stated in the comments each iteration will have it's own <h:form with it's own <input type="hidden" name="vid". When a file is uploaded the handleFileUpload will be fired with the data of the enclosing form, thus the vid parameter will be sent with the correct #{v.id}

更新2

正如BalusC所说，您最好以这种方式获取vid参数:

As BalusC commented you should preferably get vid parameter this way :

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

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