Android上传文件到服务端并显示进度条

private ProgressBar mPgBar; 
class UploadTask extends AsyncTask{ 
  private DataOutputStream outputStream = null; 
  private String fileName; 
  private String uri; 
  private String mLineEnd = "\r\n"; 
  private String mTwoHyphens = "--"; 
  private String boundary = "*****"; 
  File uploadFile ; 
  long mTtotalSize ; // Get size of file, bytes 
  public UploadTask(String fileName,String uri){ 
   this.fileName = fileName; 
   this.uri = uri; 
   uploadFile= new File(fileName); 
    mTtotalSize = uploadFile.length(); 
  } 
 
  /** 
   * 开始上传文件 
   * @param objects 
   * @return 
   */ 
  @Override 
  protected Void doInBackground(Object... objects) { 
   long length = 0; 
   int mBytesRead, mbytesAvailable, mBufferSize; 
   byte[] buffer; 
   int maxBufferSize = 256 * 1024;// 256KB 
   try{ 
 
    FileInputStream fileInputStream = new FileInputStream(new File(fileName)); 
 
    URL url = new URL(uri); 
 
    HttpURLConnection con = (HttpURLConnection) url.openConnection(); 
 
    //如果有必要则可以设置COOKIE 
//    conn.setRequestProperty("COOKIE","JSESSIOnID="+COOKIE); 
 
    // Set size of every block for post 
 
    con.setChunkedStreamingMode(256 * 1024);// 256KB 
 
    // Allow Inputs & Outputs 
    con.setDoInput(true); 
    con.setDoOutput(true); 
    con.setUseCaches(false); 
 
    // Enable POST method 
    con.setRequestMethod("POST"); 
    con.setRequestProperty("Connection", "Keep-Alive"); 
    con.setRequestProperty("Charset", "UTF-8"); 
    con.setRequestProperty("Content-Type", 
      "multipart/form-data;boundary=" + boundary); 
 
    outputStream = new DataOutputStream( 
      con.getOutputStream()); 
    outputStream.writeBytes(mTwoHyphens + boundary + mLineEnd); 
    outputStream.writeBytes("Content-Disposition: form-data; name=\"file\"; filename=\"" + fileName + "\"" + mLineEnd); 
    outputStream.writeBytes("Content-Type:application/octet-stream \r\n"); 
    outputStream.writeBytes(mLineEnd); 
 
    mbytesAvailable = fileInputStream.available(); 
    mBufferSize = Math.min(mbytesAvailable, maxBufferSize); 
    buffer = new byte[mBufferSize]; 
 
    // Read file 
    mBytesRead = fileInputStream.read(buffer, 0, mBufferSize); 
 
    while (mBytesRead > 0) { 
     outputStream.write(buffer, 0, mBufferSize); 
     length += mBufferSize; 
 
     publishProgress((int) ((length * 100) / mTtotalSize)); 
 
     mbytesAvailable = fileInputStream.available(); 
 
     mBufferSize = Math.min(mbytesAvailable, maxBufferSize); 
 
     mBytesRead = fileInputStream.read(buffer, 0, mBufferSize); 
    } 
    outputStream.writeBytes(mLineEnd); 
    outputStream.writeBytes(mTwoHyphens + boundary + mTwoHyphens 
      + mLineEnd); 
    publishProgress(100); 
 
    // Responses from the server (code and message) 
    int serverRespOnseCode= con.getResponseCode(); 
    String serverRespOnseMessage= con.getResponseMessage(); 
    fileInputStream.close(); 
    outputStream.flush(); 
    outputStream.close(); 
 
   } catch (Exception ex) { 
    ex.printStackTrace(); 
    Log.v(TAG,"uploadError"); 
   } 
   return null; 
  } 
 
  @Override 
  protected void onProgressUpdate(Integer... progress) { 
   mPgBar.setProgress(progress[0]); 
  } 
 } 

//上传文件集合 
 private List file; 
 //上传文件名集合 
 private List fileFileName; 
 //上传文件内容类型集合 
 private List fileContentType; 
 
 public List getFile() { 
  return file; 
 } 
 
 public void setFile(List file) { 
  this.file = file; 
 } 
 
 public List getFileFileName() { 
  return fileFileName; 
 } 
 
 public void setFileFileName(List fileFileName) { 
  this.fileFileName = fileFileName; 
 } 
 
 public List getFileContentType() { 
  return fileContentType; 
 } 
 
 public void setFileContentType(List fileContentType) { 
  this.fileCOntentType= fileContentType; 
 } 

public String testUpload()throws Exception{ 
  System.out.println("success"); 
  uploadFile(0); 
  return SUCCESS; 
 } 

/** 
  * 上传功能 
  * @param i 
  * @return 
  * @throws FileNotFoundException 
  * @throws IOException 
  */ 
 private String uploadFile(int i) throws FileNotFoundException, IOException { 
   
  try { 
   InputStream in = new FileInputStream(file.get(i)); 
 
   //String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR); 
    
   String dir = "D://UploadData/"; 
 
   File uploadFile = new File(dir,StringUtils.getUUID()+getFile( this.getFileFileName().get(i))); 
 
   OutputStream out = new FileOutputStream(uploadFile); 
 
   byte[] buffer = new byte[1024 * 1024]; 
 
   int length; 
   while ((length = in.read(buffer)) > 0) { 
    out.write(buffer, 0, length); 
   } 
 
   in.close(); 
   out.close(); 
   //然后进行计算 
   return uploadFile.getAbsolutePath(); 
  } catch (FileNotFoundException ex) { 
   ex.printStackTrace(); 
  } catch (IOException ex) { 
   ex.printStackTrace(); 
  } 
  return null; 
 }