1 public HttpServletResponse download(String path, HttpServletResponse response) { 2         try { 3             // path是指欲下载的文件的路径。 4             File file = new File(path); 5             // 取得文件名。 6             String filename = file.getName(); 7             // 取得文件的后缀名。 8             String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase(); 9 10             // 以流的形式下载文件。11             InputStream fis = new BufferedInputStream(new FileInputStream(path));12             byte[] buffer = new byte[fis.available()];13             fis.read(buffer);14             fis.close();15             // 清空response16             response.reset();17             // 设置response的Header18             response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));19             response.addHeader("Content-Length", "" + file.length());20             OutputStream toClient = new BufferedOutputStream(response.getOutputStream());21             response.setContentType("application/octet-stream");22             toClient.write(buffer);23             toClient.flush();24             toClient.close();25         } catch (IOException ex) {26             ex.printStackTrace();27         }28         return response;29     }30 31     public void downloadLocal(HttpServletResponse response) throws FileNotFoundException {32         // 下载本地文件33         String fileName = "Operator.doc".toString(); // 文件的默认保存名34         // 读到流中35         InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路径36         // 设置输出的格式37         response.reset();38         response.setContentType("bin");39         response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");40         // 循环取出流中的数据41         byte[] b = new byte[100];42         int len;43         try {44             while ((len = inStream.read(b)) > 0)45                 response.getOutputStream().write(b, 0, len);46             inStream.close();47         } catch (IOException e) {48             e.printStackTrace();49         }50     }51 52     public void downloadNet(HttpServletResponse response) throws MalformedURLException {53         // 下载网络文件54         int bytesum = 0;55         int byteread = 0;56 57         URL url = new URL("windine.blogdriver.com/logo.gif");58 59         try {60             URLConnection conn = url.openConnection();61             InputStream inStream = conn.getInputStream();62             FileOutputStream fs = new FileOutputStream("c:/abc.gif");63 64             byte[] buffer = new byte[1204];65             int length;66             while ((byteread = inStream.read(buffer)) != -1) {67                 bytesum += byteread;68                 System.out.println(bytesum);69                 fs.write(buffer, 0, byteread);70             }71         } catch (FileNotFoundException e) {72             e.printStackTrace();73         } catch (IOException e) {74             e.printStackTrace();75         }76     }