```java
public HttpServletResponse downLoad(String path, String file_name, HttpServletResponse response) {
try {
// path是指欲下载的文件的路径。
//判断是否为tomcat路径下文件
if (path.startsWith(Globals.APP_BASE_NAME)) {
String[] paths = path.split(Globals.APP_BASE_NAME);
path = paths[1];
path = Mvcs.getServletContext().getRealPath(path);
}
File file = new File(path);
// 取得文件名。
String filename = "\"" + file_name + "\"";
// 取得文件的后缀名。
String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
// 以流的形式下载文件。
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 设置response的Header
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes("GB2312"), "iso8859-1"));
response.addHeader("Content-Length", "" + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
toClient.write(buffer);
toClient.flush();
toClient.close();
} catch (IOException ex) {
ex.printStackTrace();
}
return response;
}