java下载文件

 1 public void downloadTmp(HttpServletRequest request,HttpServletResponse response){
 2         try {
 3             request.setCharacterEncoding("UTF-8"); 5             //第一步：设置响应类型
 6             response.setContentType("application/force-download");//应用程序强制下载
 7             //第二读取文件
 8             String path = request.getServletContext().getRealPath(File.separator+"source"+File.separator+"tmp.txt");
 9             InputStream in = new FileInputStream(path);
10             //设置响应头，对文件进行url编码
11             //name = URLEncoder.encode(name, "UTF-8");
12             response.setHeader("Content-Disposition", "attachment;filename=tmp.txt");
13             response.setContentLength(in.available());
14 
15             OutputStream out = response.getOutputStream();
16             byte[] b = new byte[1024];
17             int len = 0;
18             while((len = in.read(b))!=-1){
19                 out.write(b, 0, len);
20             }
21             out.flush();
22             out.close();
23             in.close();
24         }catch (Exception e){
25             e.printStackTrace();
26         }
27     }