Question

how to retrieve the printer response from the Bluetooth printer in android by using X-On and X-Off. I have tried but It is not working. I have tried with the following code but it is not working:

CommPortIdentifier portId  = CommPortIdentifier.getPortIdentifier("COM");
SerialPort sPort = (SerialPort)portId .open(this.getClass().getName(), 30000);
sPort.setSerialPortParams(9600, SerialPort.DATABITS_8,SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
                                            sPort.setFlowControlMode(SerialPort.FLOWCONTROL_XONXOFF_IN | SerialPort.FLOWCONTROL_XONXOFF_OUT);

 OutputStream os = sPort.getOutputStream();
 os=  sPort.getOutputStream();
 InputStream is = sPort.getInputStream(); 
os.write(baos.toByteArray(), 0, baos.toByteArray().length);
 StringBuffer inputBuffer = new StringBuffer();

do{
     for(int newData = is.read();newData != -1; newData = is.read())
      {
        inputBuffer.append((char)newData);
      }

      try
       {
         Thread.sleep(300);
       }
      catch
       {
       }
  }while(inputBuffer.length() <= 0);

String sDataIn = inputBuffer.toString();

在上面的程序中，当流程出现在以下行中时，它会出错： CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier（“COM”）;

错误是:: java.lang.ExceptionInInitializerError

Answer 1

咦？ Android中不存在CommPortIdentifier类。你是怎么得到这个来编译的？

此外，Android不是Windows，因此串口（如果存在）不会被称为“COM”。

如果您想与蓝牙打印机通话，请首先确保它支持RFCOMM，因为这是Android API中唯一可用的蓝牙协议，其次请参阅蓝牙教程：http://developer.android.com/guide/topics/wireless/bluetooth.html

使用Xon和Xoff从打印机获取响应

1 个答案: