通过蓝牙发送字符串

Question

我正在使用此代码将字符串发送到其他Android配对设备。输出是我需要发送的字符串，它被声明为public，但此代码无效。请帮我纠正这段代码

try{
    BluetoothDevice[] devices = (BluetoothDevice[]) bondedDevices.toArray();
    BluetoothDevice device = devices[0];
    ParcelUuid[] uuids = device.getUuids();

    BluetoothSocket socket= device.createRfcommSocketToServiceRecord(uuids[0].getUuid());
    socket.connect();
    OutputStream outputStream = socket.getOutputStream();
    outputStream.write(output.getBytes());
    Toast.makeText(getApplicationContext(), "Data Sent...", Toast.LENGTH_SHORT);
}
catch(Exception e){
    Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG);
}