还是关于蓝牙发送和接受数据的问题

Question

为什么我30秒的发送下数据给外部蓝牙，程序调试到   mmOutStream.write(data)，就出现socket.close();
private class GetDataThread extends Thread {
        private final BluetoothSocket iSocket;
        private InputStream mmInStream;
        public GetDataThread(BluetoothSocket socket) {
            iSocket = socket; 
        }        public void run() {
         try {
mmInStream = iSocket.getInputStream();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return;
}
         if(!mBTConnect)
         return;        
         {
            try {
             byte[] data = ｛1,2,3,4,5,6｝
                mmOutStream.write(data);
            } catch (IOException e) {
                Log.e("print", "Exception during write", e);
            }
         }
        Log.e(TAG, "BEGIN mConnectedThread");
        int Err = ConstDefine.enumNetPromptMsg.ErrOK;
        final int len = 9;
byte b[] = new byte[len];
Calendar now = Calendar.getInstance();
mBeginMillsecond  = now.getTimeInMillis();
        while (readflag) {
         if(!mBTConnect)
         {  
         return;
         }
            try {                     
                if(mmInStream.read(b) != -1){         
             
                }
            }catch (IOException e) {
                Log.e(TAG, "disconnected", e);
                cancel();
                break;
            }        
         }            
        }
       
        public void cancel() {
            try {
            
             if(mmOutStream != null){mmOutStream.close();}
                    if(mmInStream != null){mmInStream.close();}
                   // if(mmSocket != null){mmSocket.close();}
            } catch (IOException e) {
                //Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }