primefaces的fileUpload组件中fileUploadListener一直不执行是咋回事？求大神帮解

primefaces的fileUpload组件中fileUploadListener一直不执行是怎么回事？求大神帮解
如题。
1）web.xml配置如下：
<filter>
        <filter-name>PrimeFaces FileUpload Filter</filter-name>
        <filter-class>
            org.primefaces.webapp.filter.FileUploadFilter
        </filter-class>
        <init-param>
            <param-name>thresholdSize</param-name>
            <param-value>51200</param-value>
        </init-param>
        <init-param>
            <param-name>uploadDirectory</param-name>
            <param-value>/*</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>PrimeFaces FileUpload Filter</filter-name>
        <servlet-name>Faces Servlet</servlet-name>
    </filter-mapping>
    <mime-mapping>  
          <extension>pdf</extension>  
          <mime-type>application/pdf</mime-type>  
    </mime-mapping>
    <mime-mapping>  
          <extension>txt,log,conf,sql</extension>  
          <mime-type>text/plain</mime-type>  
    </mime-mapping>
 2） .xhtml中代码如下：
<h:form enctype="multipart/form-data">
            <p:fileUpload value="#{chartTestManager.ufile}" fileUploadListener="#{chartTestManager.upTest}"/>
            <p:commandButton actionListener="#{chartTestManager.test}" value="test"/>
        </h:form>
3） 受管bean中相关代码如下：
 public void upTest(FileUploadEvent event){
        this.ufile = event.getFile();
    }

困扰了三天了，查了一些资料，始终没有有效解决。求大神解。  
------解决思路----------------------
沙发