Jsf 使用p:fileupload时，fileupload始终为空

使用primefaces5.0中的文件上载时，上载的文件始终为空

观点：

<h:form enctype="multipart/form-data"  style="text-align:center;">
    <p:fileUpload value="#{noteController.fileName}" mode="simple" skinSimple="true" />
    <p:commandButton  class="btn btn-success" value="Upload file" ajax="false"  actionListener="#{noteController.upload}" />
</h:form>

在web.xml中，我添加了以下内容：

<context-param>
    <param-name>primefaces.UPLOADER</param-name>
    <param-value>commons</param-value>
</context-param>

<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>
        org.primefaces.webapp.filter.FileUploadFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>

---

结果：fileName始终为null，并且视图不会重定向到错误视图。触发操作上载时，视图仍保持在同一页面上。

Remove skinSimple=true，这对我很有效。 不管怎样，我还在努力寻找原因

<context-param>
    <param-name>primefaces.UPLOADER</param-name>
    <param-value>commons</param-value>
</context-param>

<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>
        org.primefaces.webapp.filter.FileUploadFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>