打印安卓二维码浓度低，无法使用和连接异常和断开连接异常的问题 about bluetooth_print HOT 2 CLOSED

    private byte[] buffer = new byte[100];

    public PrinterReader() {
        isRun = true;
    }

    @Override
    public void run() {
        try {
            while (isRun) {
                //读取打印机返回信息,打印机没有返回纸返回-1
                Log.e(TAG,"wait read ");
                **int len = readDataImmediately(buffer);**
                Log.e(TAG," read "+len);
                if (len > 0) {
                    Message message = Message.obtain();
                    message.what = READ_DATA;
                    Bundle bundle = new Bundle();
                    bundle.putInt(READ_DATA_CNT, len); //数据长度
                    bundle.putByteArray(READ_BUFFER_ARRAY, buffer); //数据
                    message.setData(bundle);
                    mHandler.sendMessage(message);
                }
            }
        } catch (Exception e) {//异常断开
            if (deviceConnFactoryManagers[id] != null) {
                closePort(id);
                mHandler.obtainMessage(Constant.abnormal_Disconnection).sendToTarget();
            }
        }
    }

    public void cancel() {
        isRun = false;
    }
}