struts2在配置文件中调用Action的方法返回值

//文件下载名
    public String getDownloadFileName(){
        String downloadFileName = "";
        String filename = fileName + ".xls";
        try {
            downloadFileName = URLEncoder.encode(filename,"UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return downloadFileName;
    }

<!-- 文件Excel模板下载 -->
        <action name="exportWebExcel" class="Action.Excel.ExportWebExcel">
            <result type="stream">
                <!-- 其他的参数在类中设置或者使用默认 -->
                <param name="contentType">application/octet-stream</param>
                <param name="inputName">inputStream</param>
                <param name="contentDisposition">attachment;filename="${downloadFileName}"</param>
                <param name="bufferSize">8192</param>
            </result>
        </action>