1:浏览器请求下载
public void listStockcodeUplaod(HttpServletRequest req, HttpServletResponse res) throws Exception { String urlPath = req.getParameter("url"); String name = req.getParameter("name"); URL url = new URL(urlPath); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); // 设置超时间为3秒 conn.setConnectTimeout(10 * 1000); // 防止屏蔽程序抓取而返回403错误 // conn.setRequestProperty("User-Agent", // "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)"); // 得到输入流 InputStream inputStream = conn.getInputStream(); // 获取自己数组 byte[] getData = new byte[1024]; int len = 0; ByteArrayOutputStream bos = new ByteArrayOutputStream(); while ((len = inputStream.read(getData)) != -1) { bos.write(getData, 0, len); } bos.close(); getData = bos.toByteArray(); // 以流的形式下载文件。 // byte[] buffer = new byte[fis.available()]; inputStream.read(getData); inputStream.close(); // 清空response res.reset(); // 设置response的Header res.addHeader("Content-Disposition", "attachment;filename=sss.pdf"); res.addHeader("Content-Length", "" + getData.length); OutputStream toClient = new BufferedOutputStream(res.getOutputStream()); res.setContentType("application/octet-stream"); toClient.write(getData); toClient.flush(); toClient.close(); System.out.println("info:" + url + " download success"); }
2.同上
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(); } }
3.支持在线打开文件的一种方式
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(); }
4 url下载到本地
/** * 从网络Url中下载文件 * @param urlStr * @param fileName * @param savePath * @throws IOException */ public static void downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{ URL url = new URL(urlStr); HttpURLConnection conn = (HttpURLConnection)url.openConnection(); //设置超时间为3秒 conn.setConnectTimeout(3*1000); //防止屏蔽程序抓取而返回403错误 conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)"); //得到输入流 InputStream inputStream = conn.getInputStream(); //获取自己数组 byte[] getData = readInputStream(inputStream); //文件保存位置 File saveDir = new File(savePath); if(!saveDir.exists()){ saveDir.mkdir(); } File file = new File(saveDir+File.separator+fileName); FileOutputStream fos = new FileOutputStream(file); fos.write(getData); if(fos!=null){ fos.close(); } if(inputStream!=null){ inputStream.close(); } System.out.println("info:"+url+" download success"); } /** * 从输入流中获取字节数组 * @param inputStream * @return * @throws IOException */ public static byte[] readInputStream(InputStream inputStream) throws IOException { byte[] buffer = new byte[1024]; int len = 0; ByteArrayOutputStream bos = new ByteArrayOutputStream(); while((len = inputStream.read(buffer)) != -1) { bos.write(buffer, 0, len); } bos.close(); return bos.toByteArray(); } public static void main(String[] args) { try{ downLoadFromUrl("http://101.95.48.97:8005/res/upload/interface/apptutorials/manualstypeico/6f83ce8f-0da5-49b3-bac8-fd5fc67d2725.png", "百度.jpg","d:/resource/images/diaodiao/country/"); }catch (Exception e) { // TODO: handle exception } }