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 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(); } |