spring mvc 用SmartUpload组建进行上传下载

Question

smu.initialize(this.getServletConfig(),request,response);这句的getServletConfig()怎么搞，我知道servlet是通过继承HttpServlet，哪spring mvc，我获取的时候总是返回一个null，求大神

String filepath=null;
String filename=null;
SmartUpload smu=new SmartUpload();
try {
smu.initialize(this.getServletConfig(),request,response);
} catch (Exception e) {
System.out.println(e.getMessage());
}
try {
smu.upload();
com.jspsmart.upload.File file=null;
file=smu.getFiles().getFile(0);
if(!file.isMissing()){
filepath="upload\";
filename=file.getFieldName();
filepath+=filename;
file.saveAs(filepath, SmartUpload.SAVE_VIRTUAL);
}