public  class FileDownloadHelper {
     private  static  final String TAG = "FileDownloadHelper";
     /**  线程池  */
     private ThreadPool mPool =  new ThreadPool();
     /**  开始下载  */
     public  static  final  int MESSAGE_START = 0;
     /**  更新进度  */
     public  static  final  int MESSAGE_PROGRESS = 1;
     /**  下载结束  */
     public  static  final  int MESSAGE_STOP = 2;
     /**  下载出错  */
     public  static  final  int MESSAGE_ERROR = 3;
     /**  中途终止  */
     private  volatile  boolean mIsStop =  false;
     private Handler mHandler;
     public  volatile HashMap<String, String> mDownloadUrls =  new HashMap<String, String>();

     public FileDownloadHelper(Handler handler) {
         if (handler ==  null)
             throw  new IllegalArgumentException("handler不能为空!");

         this.mHandler = handler;
    }

     public  void stopALl() {
        mIsStop =  true;
        mPool.stop();
    }

     public  void newDownloadFile( final String url) {
        newDownloadFile(url, Environment.getExternalStorageDirectory() + "/" + FileUtils.getUrlFileName(url));
    }

     /**
     * 下载一个新的文件
     * 
     *  @param  url
     *  @param  savePath
      */
     public  void newDownloadFile( final String url,  final String savePath) {
         if (mDownloadUrls.containsKey(url))
             return;
         else
            mDownloadUrls.put(url, savePath);
        mPool.start( new Runnable() {

            @Override
             public  void run() {
                mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_START, url));
                HttpClient client =  new DefaultHttpClient();
                HttpGet get =  new HttpGet(url);
                InputStream inputStream =  null;
                FileOutputStream outputStream =  null;
                 try {
                    HttpResponse response = client.execute(get);
                    HttpEntity entity = response.getEntity();
                     final  int size = ( int) entity.getContentLength();
                    inputStream = entity.getContent();
                     if (size > 0 && inputStream !=  null) {
                        outputStream =  new FileOutputStream(savePath);
                         int ch = -1;
                         byte[] buf =  new  byte[1024];
                         // 每秒更新一次进度
                         new Timer().schedule( new TimerTask() {

                            @Override
                             public  void run() {
                                 try {
                                    FileInputStream fis =  new FileInputStream( new File(savePath));
                                     int downloadedSize = fis.available();
                                     if (downloadedSize >= size)
                                        cancel();
                                    mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_PROGRESS, downloadedSize, size, url));
                                }  catch (Exception e) {

                                }
                            }
                        }, 50, 1000);

                         while ((ch = inputStream.read(buf)) != -1 && !mIsStop) {
                            outputStream.write(buf, 0, ch);
                        }
                        outputStream.flush();
                    }
                }  catch (Exception e) {
                    Log.e(TAG, e.getMessage(), e);
                    mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_ERROR, url + ":" + e.getMessage()));
                }  finally {
                     try {
                         if (outputStream !=  null)
                            outputStream.close();
                    }  catch (IOException ex) {
                    }
                     try {
                         if (inputStream !=  null)
                            inputStream.close();
                    }  catch (IOException ex) {
                    }
                }
                mDownloadUrls.remove(url);
                mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_STOP, url));
            }
        });
    }

     public Handler mDownloadHandler =  new Handler() {
        @Override
         public  void handleMessage(Message msg) {
            PFile p;
            String url = msg.obj.toString();
             switch (msg.what) {
             case FileDownloadHelper.MESSAGE_START: // 开始下载
                p =  new PFile();
                p.path = mParent.mFileDownload.mDownloadUrls.get(url);
                p.title =  new File(p.path).getName();
                p.status = 0;
                p.file_size = 0;
                 if (mDownloadAdapter ==  null) {
                    mDownloadAdapter =  new FileAdapter(getActivity(),  new ArrayList<PFile>());
                    mDownloadAdapter.add(p, url);
                    mTempListView.setAdapter(mDownloadAdapter);
                    mTempListView.setVisibility(View.VISIBLE);
                }  else {
                    mDownloadAdapter.add(p, url);
                    mDownloadAdapter.notifyDataSetChanged();
                }
                 break;
             case FileDownloadHelper.MESSAGE_PROGRESS: // 正在下载
                p = mDownloadAdapter.getItem(url);
                p.temp_file_size = msg.arg1;
                p.file_size = msg.arg2;
                 int status = ( int) ((msg.arg1 * 1.0 / msg.arg2) * 10);
                 if (status > 10)
                    status = 10;
                p.status = status;
                mDownloadAdapter.notifyDataSetChanged();
                 break;
             case FileDownloadHelper.MESSAGE_STOP: // 下载结束
                p = mDownloadAdapter.getItem(url);
                FileBusiness.insertFile(getActivity(), p);
                 break;
             case FileDownloadHelper.MESSAGE_ERROR:
                Toast.makeText(getActivity(), url, Toast.LENGTH_LONG).show();
                 break;
            }
             super.handleMessage(msg);
        }

                 if (FileUtils.isVideoOrAudio(url)) {
                    Dialog dialog =  new AlertDialog.Builder(getActivity()).setIcon(android.R.drawable.btn_star).setTitle("播放/下载").setMessage(url).setPositiveButton("播放",  new OnClickListener() {
                        @Override
                         public  void onClick(DialogInterface dialog,  int which) {
                            Intent intent =  new Intent(getActivity(), VideoPlayerActivity. class);
                            intent.putExtra("path", url);
                            startActivity(intent);
                        }
                    }).setNeutralButton("下载",  new OnClickListener() {
                        @Override
                         public  void onClick(DialogInterface dialog,  int which) {
                            MainFragmentActivity activity = (MainFragmentActivity) getActivity();
                            activity.mFileDownload.newDownloadFile(url);
                            Toast.makeText(getActivity(), "正在下载 .." + FileUtils.getUrlFileName(url) + " ，可从本地视频查看进度！", Toast.LENGTH_LONG).show();
                        }
                    }).setNegativeButton("取消",  null).create();
                    dialog.show();
                     return  true;