You can. Set the reponse header with your file name. Something like this
fileName = dateString+"_マイページ情報.xls";
fileName = URLEncoder.encode(fileName,"UTF-8");
try {
response.setContentType("application/ms-excel; charset=UTF-8");
response.setCharacterEncoding("UTF-8");
if(browserType.equals("IE")||browserType.equals("Chrome"))
response.setHeader("Content-Disposition","attachment; filename="+fileName);
if(browserType.endsWith("Firefox"))
response.setHeader("Content-Disposition","attachment; filename*=UTF-8''"+fileName);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}