采用普通藍(lán)牙技術(shù)，也就是BluetoothSokcet相關(guān)API進(jìn)行數(shù)據(jù)傳輸。
思路：首先準(zhǔn)備，客戶端和服務(wù)端。兩臺手機(jī)即可。
藍(lán)牙需要服務(wù)端啟動accept監(jiān)聽是否有客戶端進(jìn)行相關(guān)鏈接，在這個模式下一個服務(wù)端僅僅允許鏈接一個客戶端，一對一。其他客戶端進(jìn)行鏈接都會報timeout錯誤。
上代碼
第一步，動態(tài)申請藍(lán)牙權(quán)限

    //1.清單文件增加以下權(quán)限
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    //2.代碼申請權(quán)限
     private void applyPermission() {
        if (Build.VERSION.SDK_INT >= 23) {
            int checkPermission = ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_FINE_LOCATION);
            if (checkPermission != PackageManager.PERMISSION_GRANTED) {
                Logger.print("request permission");
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);

            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            isPermission = true;
            Toaster.show("已授權(quán)");
        } else {
            isPermission = false;
            Toaster.show("拒絕授權(quán)");
        }
    }

第二步，獲取藍(lán)牙適配器bluetoothAdapter（客戶端服務(wù)端都需要，但是服務(wù)端不需要掃描）

//獲取藍(lán)牙適配器
BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
 public void searchBluetooth(View view) {
        applyPermission();//申請權(quán)限

        if (bluetoothAdapter == null) {
            Toaster.show("不支持藍(lán)牙");
            return;
        }

        if (!bluetoothAdapter.isEnabled()) {
            bluetoothAdapter.enable();
        }
        if (bluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
            Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
            discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);//設(shè)置300內(nèi)可見
            startActivity(discoverableIntent);
        }
        doDiscovery();//掃描藍(lán)牙 客戶端需要
    }

    //開始掃描
    public void doDiscovery() {
        if (bluetoothAdapter.isDiscovering()) {
            bluetoothAdapter.cancelDiscovery();
        } else {
            bluetoothAdapter.startDiscovery();
        }
    }

第三步，客戶端注冊廣播接收藍(lán)牙

   IntentFilter intentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);//注冊廣播信號
        registerReceiver(bluetoothReceiver, intentFilter);
    private final BroadcastReceiver bluetoothReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action != null && BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                Logger.print("名稱 : " + device.getName() + "地址 : " + device.getAddress());
                if (device != null && device.getName() != null && device.getAddress() != null) {
                    blueData.add(device);
                    adapter.notifyDataSetChanged();//適配器刷新list獲取已鏈接的藍(lán)牙列表
                }
            }
        }
    };

第四步，啟動一個子線程進(jìn)行鏈接服務(wù)器的socket

  ClientThread clientThread = new ClientThread(device);
        new Thread(clientThread).start();

    class ClientThread extends Thread {

        BluetoothDevice device;

        public BluetoothSocket socket;

        public ClientThread(BluetoothDevice device) {
            this.device = device;
        }

        @Override
        public void run() {
            super.run();
            try {
                socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
                //這里的UUID必須和服務(wù)端一致，否則肯定會鏈接失敗
                bluetoothAdapter.cancelDiscovery();
                socket.connect();
                Logger.print("客戶端已鏈接服務(wù)端.");

                InputStream inputStream = socket.getInputStream();
                InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "UTF-8");
                //鏈接成功后，再次啟動一個線程不斷讀取服務(wù)器發(fā)過來的消息
                new ClientInputStream(inputStreamReader,socket).start();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

class ClientInputStream extends Thread {

        InputStreamReader br;
        BluetoothSocket socket;
        public boolean isRunning = true;

        public ClientInputStream(InputStreamReader br, BluetoothSocket socket) {
            this.br = br;
            this.socket = socket;
        }

        @Override
        public void run() {
            super.run();
            while (isRunning) {
                try {
                    char[] data = new char[1024];
                    int read = br.read(data);
                    Logger.print("服務(wù)端的消息："+new String(data,0,read));
                } catch (IOException e) {
                    e.printStackTrace();
                    try {
                        br.close();
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                    isRunning = false;
                }
            }
            Logger.print("服務(wù)器已斷開");
        }
    }

第五步，服務(wù)端 服務(wù)端其他代碼和客戶端差不多。線程不一樣還有發(fā)送消息測試

    class ServerThread extends Thread {

        BluetoothAdapter adapter;

        public BluetoothServerSocket serverSocket;

        public BluetoothSocket socket;

        public OutputStreamWriter osw;

        public ServerThread(BluetoothAdapter adapter) {
            this.adapter = adapter;
        }
        
        @Override
        public void run() {
            super.run();
            try {
                Logger.print("服務(wù)端啟動");
                serverSocket = bluetoothAdapter.listenUsingRfcommWithServiceRecord(bluetoothAdapter.getDefaultAdapter().getName()
                        , UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));//生成服務(wù)端socket
                socket = serverSocket.accept();//等待客戶端鏈接，這里會進(jìn)行阻塞。
                osw = new OutputStreamWriter(socket.getOutputStream(),"UTF-8");
                Logger.print("服務(wù)端鏈接成功");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

第七步，發(fā)送消息測試,注意要用子線程進(jìn)行發(fā)送消息

  public void sendMsg(View view) {
      Runnable runnable = new Runnable() {
          @Override
          public void run() {
              try {
                  OutputStreamWriter os = ct.osw;
                  if(os ==null){
                     Logger.print("客戶端未鏈接");
                      return;
                  }
                  String msg = "服務(wù)端測試信息";
                  os.write(msg);
                  os.flush();
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
      };
      new Thread(runnable).start();
    }