Android带进度条的文件上传示例（使用AsyncTask异步任务）

mTask = new MyTask(); 
mTask.execute(filePath, url); 

private class MyTask extends AsyncTask{ 
 
    @Override 
    protected void onPostExecute(String result) { 
      //最终结果的显示 
      mTvProgress.setText(result);   
    } 
 
    @Override 
    protected void onPreExecute() { 
      //开始前的准备工作 
      mTvProgress.setText("loading..."); 
    } 
 
    @Override 
    protected void onProgressUpdate(Integer... values) { 
      //显示进度 
      mPgBar.setProgress(values[0]); 
      mTvProgress.setText("loading..." + values[0] + "%"); 
    } 
 
    @Override 
    protected String doInBackground(String... params) { 
      //这里params[0]和params[1]是execute传入的两个参数 
      String filePath = params[0]; 
      String uploadUrl = params[1]; 
      //下面即手机端上传文件的代码 
      String end = "\r\n"; 
      String twoHyphens = "--"; 
      String boundary = "******"; 
      try { 
        URL url = new URL(uploadUrl); 
        HttpURLConnection httpURLCOnnection= (HttpURLConnection) url 
            .openConnection(); 
        httpURLConnection.setDoInput(true); 
        httpURLConnection.setDoOutput(true); 
        httpURLConnection.setUseCaches(false); 
        httpURLConnection.setRequestMethod("POST"); 
        httpURLConnection.setConnectTimeout(6*1000); 
        httpURLConnection.setRequestProperty("Connection", "Keep-Alive"); 
        httpURLConnection.setRequestProperty("Charset", "UTF-8"); 
        httpURLConnection.setRequestProperty("Content-Type", 
            "multipart/form-data;boundary=" + boundary); 
 
        DataOutputStream dos = new DataOutputStream(httpURLConnection 
            .getOutputStream()); 
        dos.writeBytes(twoHyphens + boundary + end); 
        dos 
            .writeBytes("Content-Disposition: form-data; name=\"file\"; filename=\"" 
                + filePath.substring(filePath.lastIndexOf("/") + 1) 
                + "\"" + end); 
        dos.writeBytes(end); 
 
        //获取文件总大小 
        FileInputStream fis = new FileInputStream(filePath); 
        long total = fis.available(); 
        byte[] buffer = new byte[8192]; // 8k 
        int count = 0; 
        int length = 0; 
        while ((count = fis.read(buffer)) != -1) { 
          dos.write(buffer, 0, count); 
          //获取进度，调用publishProgress() 
          length += count; 
          publishProgress((int) ((length / (float) total) * 100)); 
          //这里是测试时为了演示进度,休眠500毫秒，正常应去掉 
          Thread.sleep(500); 
        }     
        fis.close(); 
        dos.writeBytes(end); 
        dos.writeBytes(twoHyphens + boundary + twoHyphens + end); 
        dos.flush(); 
 
        InputStream is = httpURLConnection.getInputStream(); 
        InputStreamReader isr = new InputStreamReader(is, "utf-8"); 
        BufferedReader br = new BufferedReader(isr); 
        @SuppressWarnings("unused") 
        String result = br.readLine(); 
        dos.close(); 
        is.close(); 
        return "上传成功"; 
    }catch (Exception e) { 
      e.printStackTrace(); 
      return "上传失败"; 
    }   
  }