Android 文件下载三种基本方式

 public void downloadFile1() {  try{    //下载路径，如果路径无效了，可换成你的下载路径    String url = "http://c.qijingonline.com/test.mkv";    String path = Environment.getExternalStorageDirectory().getAbsolutePath();    final long startTime = System.currentTimeMillis();    Log.i("DOWNLOAD","startTime="+startTime);    //下载函数    String filename=url.substring(url.lastIndexOf("/") + 1);    //获取文件名    URL myURL = new URL(url);    URLConnection conn = myURL.openConnection();    conn.connect();    InputStream is = conn.getInputStream();    int fileSize = conn.getContentLength();//根据响应获取文件大小    if (fileSize <= 0) throw new RuntimeException("无法获知文件大小 ");    if (is == null) throw new RuntimeException("stream is null");    File file1 = new File(path);    if(!file1.exists()){      file1.mkdirs();    }    //把数据存入路径+文件名    FileOutputStream fos = new FileOutputStream(path+"/"+filename);    byte buf[] = new byte[1024];    int downLoadFileSize = 0;    do{      //循环读取      int numread = is.read(buf);      if (numread == -1)      {        break;      }      fos.write(buf, 0, numread);      downLoadFileSize += numread;      //更新进度条    } while (true);    Log.i("DOWNLOAD","download success");    Log.i("DOWNLOAD","totalTime="+ (System.currentTimeMillis() - startTime));    is.close();  } catch (Exception ex) {    Log.e("DOWNLOAD", "error: " + ex.getMessage(), ex);  }}

private void downloadFile2(){  //下载路径，如果路径无效了，可换成你的下载路径  String url = "http://c.qijingonline.com/test.mkv";  //创建下载任务,downloadUrl就是下载链接  DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));  //指定下载路径和下载文件名  request.setDestinationInExternalPublicDir("", url.substring(url.lastIndexOf("/") + 1));  //获取下载管理器  DownloadManager downloadManager= (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);  //将下载任务加入下载队列，否则不会进行下载  downloadManager.enqueue(request);}

private void downloadFile3(){  //下载路径，如果路径无效了，可换成你的下载路径  final String url = "http://c.qijingonline.com/test.mkv";  final long startTime = System.currentTimeMillis();  Log.i("DOWNLOAD","startTime="+startTime);  Request request = new Request.Builder().url(url).build();  new OkHttpClient().newCall(request).enqueue(new Callback() {    @Override    public void onFailure(Call call, IOException e) {      // 下载失败      e.printStackTrace();      Log.i("DOWNLOAD","download failed");    }    @Override    public void onResponse(Call call, Response response) throws IOException {      Sink sink = null;      BufferedSink bufferedSink = null;      try {        String mSDCardPath= Environment.getExternalStorageDirectory().getAbsolutePath();        File dest = new File(mSDCardPath,  url.substring(url.lastIndexOf("/") + 1));        sink = Okio.sink(dest);        bufferedSink = Okio.buffer(sink);        bufferedSink.writeAll(response.body().source());        bufferedSink.close();        Log.i("DOWNLOAD","download success");        Log.i("DOWNLOAD","totalTime="+ (System.currentTimeMillis() - startTime));      } catch (Exception e) {        e.printStackTrace();        Log.i("DOWNLOAD","download failed");      } finally {        if(bufferedSink != null){          bufferedSink.close();        }      }    }  });}