Java文件下载

Java文件下载的几种方式

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76

public HttpServletResponse download(String path, HttpServletResponse response) {          try {              // path是指欲下载的文件的路径。              File file = new File(path);              // 取得文件名。              String filename = file.getName();              // 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()));              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;      }        public void downloadLocal(HttpServletResponse response) throws FileNotFoundException {          // 下载本地文件          String fileName = "Operator.doc" .toString(); // 文件的默认保存名          // 读到流中          InputStream inStream = new FileInputStream( "c:/Operator.doc" ); // 文件的存放路径          // 设置输出的格式          response.reset();          response.setContentType( "bin" );          response.addHeader( "Content-Disposition" , "attachment; filename=\"" + fileName + "\"" );          // 循环取出流中的数据          byte [] b = new byte [ 100 ];          int len;          try {              while ((len = inStream.read(b)) > 0 )                  response.getOutputStream().write(b, 0 , len);              inStream.close();          } catch (IOException e) {              e.printStackTrace();          }      }        public void downloadNet(HttpServletResponse response) throws MalformedURLException {          // 下载网络文件          int bytesum = 0 ;          int byteread = 0 ;            URL url = new URL( "windine.blogdriver.com/logo.gif" );            try {              URLConnection conn = url.openConnection();              InputStream inStream = conn.getInputStream();              FileOutputStream fs = new FileOutputStream( "c:/abc.gif" );                byte [] buffer = new byte [ 1204 ];              int length;              while ((byteread = inStream.read(buffer)) != - 1 ) {                  bytesum += byteread;                  System.out.println(bytesum);                  fs.write(buffer, 0 , byteread);              }          } catch (FileNotFoundException e) {              e.printStackTrace();          } catch (IOException e) {              e.printStackTrace();          }      }

//支持在线打开文件的一种方式

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

public void downLoad(String filePath, HttpServletResponse response, boolean isOnLine) throws Exception {      File f = new File(filePath);      if (!f.exists()) {          response.sendError( 404 , "File not found!" );          return ;      }      BufferedInputStream br = new BufferedInputStream( new FileInputStream(f));      byte [] buf = new byte [ 1024 ];      int len = 0 ;        response.reset(); // 非常重要      if (isOnLine) { // 在线打开方式          URL u = new URL( "file:///" + filePath);          response.setContentType(u.openConnection().getContentType());          response.setHeader( "Content-Disposition" , "inline; filename=" + f.getName());          // 文件名应该编码成UTF-8      } else { // 纯下载方式          response.setContentType( "application/x-msdownload" );          response.setHeader( "Content-Disposition" , "attachment; filename=" + f.getName());      }      OutputStream out = response.getOutputStream();      while ((len = br.read(buf)) > 0 )          out.write(buf, 0 , len);      br.close();      out.close(); }

来自为知笔记(Wiz)