BluetoothAdapter myBluetoothAdapter = null;//蓝牙适配器 
BluetoothServerSocket mBThServer = null;//上位机<span style="font-family: Arial, Helvetica, sans-serif;">ServerSocket</span> 
BluetoothSocket mBTHSocket = null;//下位机的socket 
InputStream mmInStream = null;//输入流 
OutputStream mmOutStream = null;//输出流 
<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">    </span>

myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();//获取适配器 
Set<BluetoothDevice> pairedDevices = myBluetoothAdapter 
    .getBondedDevices();//获取适配器下的所有蓝牙设备 
if (pairedDevices.size() > 0) { 
  for (Iterator<BluetoothDevice> iterator = pairedDevices 
      .iterator(); iterator.hasNext();) { 
    BluetoothDevice device = (BluetoothDevice) iterator 
        .next(); 
    if (DEVICE_NAME1.equals(device.getName()) 
        || DEVICE_NAME2.equals(device.getName()) 
        || DEVICE_NAME3.equals(device.getName()) 
        || DEVICE_NAME4.equals(device.getName())) { 
      try { 
        myBluetoothAdapter.enable();//将适配器设置可用 
        Intent discoverableIntent = new Intent( 
            BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);// 使得蓝牙处于可发现模式，持续时间150s 
        discoverableIntent 
            .putExtra( 
                BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 
                150); 
        mBTHSocket = device 
            .createRfcommSocketToServiceRecord(MY_UUID);//获取下位机的socket 
 
        int sdk = Integer.parseInt(Build.VERSION.SDK); 
        if (sdk >= 10) { 
          mBTHSocket = device 
              .createInsecureRfcommSocketToServiceRecord(MY_UUID); 
        } else { 
          mBTHSocket = device 
              .createRfcommSocketToServiceRecord(MY_UUID); 
        } 
 
        mBThServer = myBluetoothAdapter 
            .listenUsingRfcommWithServiceRecord( 
                "myServerSocket", MY_UUID);监听可用的设备 
        mBTHSocket.connect(); // 建立连接 
        mmInStream = mBTHSocket.getInputStream();// 获取输入流 
        mmOutStream = mBTHSocket.getOutputStream();// 获取输出流 
 
      } catch (IOException e) { 
        ett.setText("设备连接异常！"); 
      } 
      if ((mmInStream != null) && (mmInStream != null))// 二者不为空时，表示连接成功，否则连接失败 
      { 
        ett.setText("设备连接成功！"); 
      } else { 
        ett.setText("设备连接失败！"); 
      } 
      break; 
    } 
  } 
} 

 if ((mmInStream == null) || (mmInStream == null)) { 
  Readflage = -2;// 连接异常 
  return; 
} 
mmOutStream.write(cmd_find);//写入查找指令 
Thread.sleep(200); 
int datalen = mmInStream.read(recData);//读取数据 

if ((mmInStream == null) || (mmInStream == null)) { 
  return; 
} 
//关闭流和socket 
mmOutStream.close(); 
mmInStream.close(); 
mBTHSocket.close(); 
mBThServer.close();