这是代码，它不显示 .csv 文件：
public class ForwardAction extends MultiAction {
private static final String FILE_ERROR = "<h3><center>INVALID FILE</center></h3>";
public ActionForward doVizualizare(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
StringBuffer sb = new StringBuffer();
sb.append("Name,Email,Phone");
sb.append(System.getProperty("line.separator"));
sb.append("Naveen,naveen@ibm.com,111-111-111");
OutputStream resOut = response.getOutputStream();
try {
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment; filename=\"a.csv\"");
resOut.write(sb.toString().getBytes());
} catch (Exception e) {
resOut.write(FILE_ERROR.getBytes());
}
return null;
}
}