Implementation of Bluetooth app Code by android

In this paper, we share the specific code of android to realize Bluetooth app for your reference. The specific contents are as follows

private BluetoothGatt bluetoothGatt;
private BluetoothGattService gattService;
private BluetoothGattCharacteristic gattCharacteristic;
private BluetoothManager bluetoothManager;
private BluetoothAdapter bluetoothAdapter;
private List<BluetoothDevice> devices = new ArrayList<>();

private UUID serviceUUID;  // Different equipment   Different uuid
private UUID characteristicUUID;   // Different equipment   Different uuid
private final UUID service4UUID= UUID.fromString("0000fff0-0000-1000-8000-00805f9b34fb");  
private final UUID charAUUID = UUID.fromString("0000fffa-0000-1000-8000-00805f9b34fb");

private LightReceiver lightReceiver;
private ScanReceiver scanReceiver;
private ListView listView;
private TextView tvrefresh;
private String lightAction;

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  Log.i("tag", "MainActivity  onCreate()");
  //
  listView = (ListView) findViewById(R.id.lv_bluetooth);
  tvrefresh = (TextView) findViewById(R.id.tv_refresh_bluetooth);
  tvrefresh.setOnClickListener(this);
  openBluetooth();
  registeLigthReceiver();
  registeScanReceiver();

}

@Override
protected void onStart() {
  super.onStart();
  Log.i("tag", "MainActivity  onStart()");
  bluetoothScan();
}

// Return 
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
  Log.i("tag", "MainActivity  onKeyUp()");
  this.finish();
  return super.onKeyUp(keyCode, event);
}

// Rescan Bluetooth 
@Override
public void onClick(View view) {
  switch (view.getId()) {
    case R.id.tv_refresh_bluetooth:
      // Bluetooth scanning 
      bluetoothScan();
      break;
    default:
      break;
  }
}

// Turn on local Bluetooth 
private void openBluetooth() {
  Log.i("tag", "openLocalBluetooth()");
  // Check whether your phone supports Bluetooth 4.0
  if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
    Toast.makeText(this, " Phone does not support Bluetooth 4.0", Toast.LENGTH_SHORT).show();
    finish();
  }
  // Call the way of system service and request to turn on Bluetooth 
  bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
  bluetoothAdapter = bluetoothManager.getAdapter();
  // Turn on Bluetooth 
  if (!bluetoothAdapter.isEnabled()) {
    bluetoothAdapter.enable();
  }
}

// Start Bluetooth scanning    Scan to 1 Add 1 A 
private void bluetoothScan() {
  Log.i("tag", "bluetoothScan()");
  if (bluetoothAdapter == null) {
    openBluetooth();
  }
  if (!bluetoothAdapter.isDiscovering()) {
    bluetoothAdapter.startDiscovery();  // Callback 
  } else {
    Toast.makeText(this, " Scanning ..", Toast.LENGTH_SHORT).show();
  }
}

// Update the data in the Bluetooth list 
private void updateUi() {
  Log.i("tag", "updateUi()");
  if (devices != null && devices.size() > 0) {
    BlueAdapter adapter = new BlueAdapter(this, devices);
    listView.setAdapter(adapter);
    adapter.notifyDataSetChanged();
  } else {
    Toast.makeText(this, " There is no Bluetooth nearby ", Toast.LENGTH_SHORT).show();
  }
}

// Acquire gatt  Corresponding service
private BluetoothGattService getGattService(BluetoothGatt gatt, UUID serviceUUID) {
  List<BluetoothGattService> gattServices = gatt.getServices();
  for (BluetoothGattService gattService : gattServices) {
    if (gattService.getUuid().equals(serviceUUID)) {
      return gattService;
    }
  }
  return null;
}

// Acquire service Corresponding characteristic
private BluetoothGattCharacteristic getGattCharacteristic(BluetoothGattService gattService, UUID characteristicUUID) {
  List<BluetoothGattCharacteristic> gattCharacteristics = gattService.getCharacteristics();
  for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
    if (gattCharacteristic.getUuid().equals(characteristicUUID)) {
      return gattCharacteristic;
    }
  }
  return null;
}

// Register Bluetooth Scan Monitor 
private void registeScanReceiver() {
  Log.i("tag", "registeScanReceiver()");
  scanReceiver = new ScanReceiver();
  IntentFilter filter = new IntentFilter();
  filter.addAction(BluetoothDevice.ACTION_FOUND);
  filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
  registerReceiver(scanReceiver, filter);
}

// Define Bluetooth Scan Listening Class   Add device  ,   Update interface 
class ScanReceiver extends BroadcastReceiver {

  @Override
  public void onReceive(Context context, Intent intent) {
    Log.i("tag", " BluetoothReceiver / ScanReceiver onReceive()  action=" + intent.getAction());
    String scanAction = intent.getAction();
    if (scanAction.equals(BluetoothDevice.ACTION_FOUND)) {
      BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
      if (!devices.contains(device)) {
        devices.add(device);
        if (CacheUtils.getBlueDeviceString(MainActivity1.this, device.getAddress()).equals("")) {
          CacheUtils.putBlueDeviceString(MainActivity1.this, device.getAddress(), device.getName());
        }
        updateUi();
      }
    } else if (scanAction.equals(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)) {
      if (devices == null || devices.size() == 0) {
        Toast.makeText(MainActivity1.this, " No Bluetooth devices were found nearby ", Toast.LENGTH_SHORT).show();
      }
    }
  }
}

// Register light monitoring 
private void registeLigthReceiver() {
  Log.i("tag", "registeReceiver()");
  lightReceiver = new LightReceiver();
  IntentFilter filter = new IntentFilter();
  filter.addAction("openLight");
  filter.addAction("closeLight");
  registerReceiver(lightReceiver, filter);
}

// Define a light monitor class 
class LightReceiver extends BroadcastReceiver {

  @Override
  public void onReceive(Context context, Intent intent) {

    Log.i("tag", " BluetoothReceiver  /LightReceiver onReceive()  action=" + intent.getAction());
    //
    String address = intent.getStringExtra("bluetoothAddress");  // From adapter Data obtained 
    lightAction = intent.getAction();
    // if()    Different equipment    Different serviceUUID , different characteristicUUID  Determine for yourself 
    serviceUUID=service4UUID;
    characteristicUUID=charAUUID;

    if (bluetoothAdapter == null) {
      openBluetooth();
    }
    BluetoothDevice device = bluetoothAdapter.getRemoteDevice(address);  
    MyBluetoothGattCallback gattCallback = new MyBluetoothGattCallback();
    bluetoothGatt = device.connectGatt(MainActivity1.this, false, gattCallback);  // Callback 

  }
}

// Bluetooth connection / Communication callback 
class MyBluetoothGattCallback extends android.bluetooth.BluetoothGattCallback {
  @Override
  public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
    super.onConnectionStateChange(gatt, status, newState);
    Log.i("tag", "MyBluetoothGattCallback  onConnectionStateChange()  newState=" + newState);
    if (newState == BluetoothProfile.STATE_CONNECTED) {
      gatt.discoverServices();       // Connection succeeded, search service started, 1 You must call this method, or you will not get the service 
      Log.i("tag", "MyBluetoothGattCallback  STATE_CONNECTED  ");
    } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
      Log.i("tag", "MyBluetoothGattCallback  STATE_DISCONNECTED");
    }
  }

  @Override
  public void onServicesDiscovered(BluetoothGatt gatt, int status) {
    super.onServicesDiscovered(gatt, status);
    Log.i("tag", "MyBluetoothGattCallback  onServicesDiscovered() status=" + status);

    if (lightAction.equals("openLight") || lightAction.equals("closeLight")) {  // Avoid   Constantly updated 
      if (gattService == null || gattCharacteristic == null || !serviceUUID.equals(service4UUID) || !characteristicUUID.equals(charAUUID)) {
        gattService = getGattService(gatt, serviceUUID);
        if (gattService != null) {
          gattCharacteristic = getGattCharacteristic(gattService, characteristicUUID);
          if (gattCharacteristic != null) {
            gatt.setCharacteristicNotification(gattCharacteristic, true);
            gatt.connect();
          }
        }
      }
      if (lightAction.equals("openLight")) {
        gattCharacteristic.setValue("openLight"); // Set it yourself here   Data required by Bluetooth module 
        gatt.writeCharacteristic(gattCharacteristic);
      } else if (lightAction.equals("closeLight")) {
        gattCharacteristic.setValue("closeLight"); // Set it yourself here   Data required by Bluetooth module 
        gatt.writeCharacteristic(gattCharacteristic);
      }
      lightAction = "";
      gatt.readRemoteRssi();
    }
  }
}

@Override
protected void onDestroy() {
  super.onDestroy();
  Log.i("tag", "onDestroy()");
  if (bluetoothAdapter != null) {
    bluetoothAdapter.disable();
    bluetoothAdapter = null;
  }
  if (bluetoothGatt != null) {
    bluetoothGatt.disconnect();
    bluetoothGatt.close();
    bluetoothGatt = null;
  }

  if (lightReceiver != null) {
    unregisterReceiver(lightReceiver);
    lightReceiver = null;
  }
  if (scanReceiver != null) {
    unregisterReceiver(scanReceiver);
    scanReceiver = null;
  }
}