java 网络文件下载（并命中文名）

public void download(HttpServletRequest request, HttpServletResponse response){
        //获取服务器文件
        String file_url = "http//:www.baidu.com/201811239413.doc";

        InputStream ins = null;
        try {
            ins = new URL(file_url).openStream();
            /* 设置文件ContentType类型，这样设置，会自动判断下载文件类型 */
            response.setContentType("multipart/form-data");
            /* 设置文件头：最后一个参数是设置下载文件名 */
            response.setHeader("Content-Disposition", "attachment;filename*=UTF-8''" + URLEncoder.encode("江苏南京.doc","UTF-8"));//适应中文名称
            OutputStream os = response.getOutputStream();
            byte[] b = new byte[1024];
            int len;
            while((len = ins.read(b)) > 0){
                os.write(b,0,len);
            }
            os.flush();
            os.close();
            ins.close();
        } catch (FileNotFoundException e) {
            System.out.println("没有该文件");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }