JAVA实现CSV文件下载,后缀名错误

今天下了个类下载CSV文件的..但用弹出的对话框保存可以..但用迅雷保存后缀名就变成.do的了..不是.csv文件了..大家帮个忙..看看..代码如下:
public ActionForward downloadCSVFile(ActionMapping mapping,
ActionForm form, HttpServletRequest request,
HttpServletResponse response) {
String method = "downloadCSVFile";
String userId = (String) request.getSession().getAttribute("Portal"); PrintWriter pw = null;
response.setContentType("application/octet-stream;charset=GBK");
response.setHeader("Content-Disposition",
"attachment; filename=\"mealordering.csv\"");
List allOrderHistoryList = new LinkedList(); String strHead = Constant.RESTAURANT_NAME + "," + Constant.MEAL_NAME
+ "," + Constant.MEAL_PRICE + "," + Constant.NUM + ","
+ Constant.SUBSCRIBER_NAME + "," + Constant.ORDER_TIME; try {
pw = response.getWriter();
pw.println(strHead);

allOrderHistoryList = (List)request.getSession().getAttribute("addOrderHistory_list"); if (allOrderHistoryList == null || allOrderHistoryList.size() <= 0) { this.debug("'", method, Constant.MESSAGE_QUERY_NOELEMENT); } else {

for (Iterator iterator = allOrderHistoryList.iterator(); iterator
.hasNext();) {
OrderHistory orderHistory = (OrderHistory) iterator.next();
String restName = String.valueOf(orderHistory.getMeal()
.getRestaurant().getRestName());
String mealName = String.valueOf(orderHistory.getMeal()
.getMealName());
String mealPrice = String.valueOf(orderHistory.getMeal()
.getSinglePrice());
String num = String.valueOf(orderHistory.getNum());
String subscriber = String.valueOf(orderHistory
.getEmployee().getFullName());
String orderTime = String.valueOf(orderHistory.getTime()); String strLine = "\"" + restName + "\",\"" + mealName
+ "\",\"" + mealPrice + "\",\"" + num + "\",\""
+ subscriber + "\",\"" + orderTime + "\""; pw.println(strLine);
}
pw.flush();
pw.close();
}
} catch (IOException e) {
e.printStackTrace();
this.debug(userId, method, "IOException");
}
return null;
}