java实现文件下载的两种方式

本文实例为大家分享了java实现文件下载的具体代码，供大家参考，具体内容如下

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

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();  }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。