我在用servlet写了一个下载功能，先把文件打包成RAR，然后通过SERVLET下载，但遇到了无法下载的问题。
出现问题的截图：
代码是：
public void exportDown(HttpRequest request, HttpServletResponse response,
User user) throws ServletException, IOException {
ExportLogApp app = new ExportLogApp(
"from Test1 where 1=1 and id <1001 ");
int i = app.exportDownRAR(user.getId(), null, null);
if (i == app.LOG) {
user.addLog("数据交换", "导出下载数据", "用户[" + user.getId() + "]导出数据成功！");
String filePath = app.getRARpath_save() + File.separator
+ app.getRARname_save() + ".rar";
filePath = filePath.replaceAll("/", "\\\\");
// 定义输出类型(下载)
response.setContentType("application/force-download");
// 定义输出文件头
response.setHeader("Content-Disposition", "attachment;filename=\""
+ app.getRARname_save() + ".rar\"");
File file = new File(filePath);
int len = (int) file.length();
byte[] buf = new byte[len];
FileInputStream fis = new FileInputStream(file);
OutputStream out = response.getOutputStream();
len = fis.read(buf);
out.write(buf, 0, len);
out.flush();
out.close();
fis.close();
file.delete();
} else if (i == app.LOG_ERROR) {
user.addLog("数据交换", "导出下载数据", "用户[" + user.getId() + "]导出数据失败！");
PrintWriter out = response.getWriter();
out.println("<script language='javascript'>");
out.println("alert('导出数据出错，请联系管理员！');");
out.println("window.location.href='../expert/expert_account.jsp';");
out.println("window.close()");
out.println("</script>");
} else if (i == app.NO_DATA) {
}
}
请帮我解答下，为什么会这样，我测试用的浏览器是IE7.
