请求参数在servlet中不可用

Question

我无法从HttpServletRequest中读取参数：

我试过这种方法但没有工作。 public FormData readFormData（HttpServletRequest request，HttpServletResponse response，FilterChain chain）抛出IOException，ServletException，ParseException     {         FormData formData = null;         枚举paramNames = request.getParameterNames（）;

    if(paramNames.hasMoreElements())
        formData = new FormData();

    while(paramNames.hasMoreElements()) 
    {
        String paramValue = null; 
        String paramName = (String)paramNames.nextElement();
        //LOGGER.info("paramName :: " + paramName);
        String[] paramValues = request.getParameterValues(paramName);
        // Read single valued data
        if (paramValues.length == 1) {
            paramValue = paramValues[0];
            /*if (paramValue.length() == 0)
                LOGGER.info("<i>No Value</i>");
            else
                LOGGER.info("paramValue :: "+paramValue);*/
        } else {
            // Read multiple valued data
            /*for(int i=0; i < paramValues.length; i++) {
                LOGGER.info("<li>" + paramValues[i]+ "</li>");
            }*/
        }

        String key = paramName;
        if (key.equalsIgnoreCase("firstname"))
            formData.setFirstName(paramValue);
        if (key.equalsIgnoreCase("lastname"))
            formData.setLastName(paramValue);
        if (key.equalsIgnoreCase("username"))
            formData.setUserName(paramValue);
        if (key.equalsIgnoreCase("appusername"))
            formData.setAppUserName(paramValue);
        if (key.equalsIgnoreCase("time"))
        {
            Date time = dateFormatter.parse(paramValue);
            formData.setTime(time);
        }
        if (key.equalsIgnoreCase("authhash"))
            formData.setAuthHash(paramValue);
        if (key.equalsIgnoreCase("mandate"))
            formData.setMandate(paramValue);            
    }


    return formData;
}

paramNames.hasMoreElements()有假值!!

使用chrome检查器可以看到参数：