java 文件下载

@RequestMapping("/download")
@ResponseBody
//filename 为上传存的文件名称，例如：201601011111_2345.png
public  void downloadFile(String filename, HttpServletResponse response,HttpServletRequest request)
throws IOException {
String destpath = "";
destpath = request.getRealPath("/upload/images") + File.separator;
filepath = destpath + filename;
File file = new File(filepath);

response.setContentType("multipart/form-data;charset=utf-8");
//防止乱码
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes("GBK"), "ISO8859-1"));
response.setCharacterEncoding("utf-8");
InputStream fis = new BufferedInputStream(new FileInputStream(file));
byte[] b = new byte[fis.available()];
fis.read(b);
response.getOutputStream().write(b);
response.getOutputStream().flush();
response.getOutputStream().close();
response.flushBuffer();
fis.close();
}