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Android ble低功耗蓝牙开发-服务端

Android ble低功耗蓝牙开发-服务端

作者: 流水潺湲 | 来源:发表于2017-12-04 14:18 被阅读372次

    BLE权限

    首先,需要在manifest中声明使用蓝牙和操作蓝牙的权限
    在应用程序清单文件中声明蓝牙权限。

         <uses-feature
            android:name="android.hardware.bluetooth_le"
            android:required="true"/>
        <uses-feature android:name="android.hardware.location.gps"/>
    
        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
        <uses-permission android:name="android.permission.BLUETOOTH"/>
        <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    

    如果您要声明自己的应用只适用于支持BLE的设备,请在应用清单中包含以下内容:

    <uses-feature android:name =“android.hardware.bluetooth_le”android:required =“true”/>
    

    在android 6.0 以后,要想获得蓝牙扫描结果,还需要下面的权限

         <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
         <!-- Needed only if your app targets Android 5.0 (API level 21) or higher.  -->
         <uses-feature android:name="android.hardware.location.gps" />
    

    设置蓝牙

    Get the BluetoothAdapter

            // Use this check to determine whether BLE is supported on the device.  Then
            // you can selectively disable BLE-related features.
            if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
                Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
                finish();
            }
    
            // Initializes Bluetooth adapter.
            mBluetoothManager =
                    (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            mBluetoothAdapter = mBluetoothManager.getAdapter();
    

    Enable Bluetooth

            // Ensures Bluetooth is available on the device and it is enabled.  If not,
            // displays a dialog requesting user permission to enable Bluetooth.
            if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
            }
    

    初始化广播

    (1)广播的设置
    (2)设置广播的数据
    (3)设置响应的数据
    (4)设置连接回调

     @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
        private void initGATTServer() {
            AdvertiseSettings settings = new AdvertiseSettings.Builder()
                    .setConnectable(true)
                    .build();
    
            AdvertiseData advertiseData = new AdvertiseData.Builder()
                    .setIncludeDeviceName(true)
                    .setIncludeTxPowerLevel(true)
                    .build();
    
            AdvertiseData scanResponseData = new AdvertiseData.Builder()
                    .addServiceUuid(new ParcelUuid(UUID_SERVER))
                    .setIncludeTxPowerLevel(true)
                    .build();
    
    
            AdvertiseCallback callback = new AdvertiseCallback() {
    
                @Override
                public void onStartSuccess(AdvertiseSettings settingsInEffect) {
                    Log.d(TAG, "BLE advertisement added successfully");
                    showText("1. initGATTServer success");
                    println("1. initGATTServer success");
                    initServices(getContext());
                }
    
                @Override
                public void onStartFailure(int errorCode) {
                    Log.e(TAG, "Failed to add BLE advertisement, reason: " + errorCode);
                    showText("1. initGATTServer failure");
                }
            };
    
            BluetoothLeAdvertiser bluetoothLeAdvertiser = mBluetoothAdapter.getBluetoothLeAdvertiser();
            bluetoothLeAdvertiser.startAdvertising(settings, advertiseData, scanResponseData, callback);
        }
    

    在被BLE设备连接后,将触发 AdvertiseCallback 的 onStartSuccess,我们在这之后,初始化GATT的服务

    初始化GATT的服务

    (1) 通过 mBluetoothManager.openGattServer() 获得 bluetoothGattServer

    (2) 添加 服务,特征,描述。这些内容要让客户端知道。

     private void initServices(Context context) {
            bluetoothGattServer = mBluetoothManager.openGattServer(context, bluetoothGattServerCallback);
            BluetoothGattService service = new BluetoothGattService(UUID_SERVER, BluetoothGattService.SERVICE_TYPE_PRIMARY);
    
            //add a read characteristic.
            characteristicRead = new BluetoothGattCharacteristic(UUID_CHARREAD, BluetoothGattCharacteristic.PROPERTY_READ, BluetoothGattCharacteristic.PERMISSION_READ);
            //add a descriptor
            BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(UUID_DESCRIPTOR, BluetoothGattCharacteristic.PERMISSION_WRITE);
            characteristicRead.addDescriptor(descriptor);
            service.addCharacteristic(characteristicRead);
    
            //add a write characteristic.
            BluetoothGattCharacteristic characteristicWrite = new BluetoothGattCharacteristic(UUID_CHARWRITE,
                    BluetoothGattCharacteristic.PROPERTY_WRITE |
                            BluetoothGattCharacteristic.PROPERTY_READ |
                            BluetoothGattCharacteristic.PROPERTY_NOTIFY,
                    BluetoothGattCharacteristic.PERMISSION_WRITE);
            service.addCharacteristic(characteristicWrite);
    
            bluetoothGattServer.addService(service);
            Log.e(TAG, "2. initServices ok");
            showText("2. initServices ok");
        }
    
    

    在 openGattServer 方法中,我们需要传入个回调
    bluetoothGattServer = mBluetoothManager.openGattServer(context, bluetoothGattServerCallback);

    配置数据交互回调

    回调时间有:连接状态变化,收发消息,通知消息

     /**
         * 服务事件的回调
         */
        private BluetoothGattServerCallback bluetoothGattServerCallback = new BluetoothGattServerCallback() {
    
            /**
             * 1.连接状态发生变化时
             * @param device
             * @param status
             * @param newState
             */
            @Override
            public void onConnectionStateChange(BluetoothDevice device, int status, int newState) {
                Log.e(TAG, String.format("1.onConnectionStateChange:device name = %s, address = %s", device.getName(), device.getAddress()));
                Log.e(TAG, String.format("1.onConnectionStateChange:status = %s, newState =%s ", status, newState));
                super.onConnectionStateChange(device, status, newState);
                currentDevice = device;
            }
    
            @Override
            public void onServiceAdded(int status, BluetoothGattService service) {
                super.onServiceAdded(status, service);
                Log.e(TAG, String.format("onServiceAdded:status = %s", status));
            }
    
            @Override
            public void onCharacteristicReadRequest(BluetoothDevice device, int requestId, int offset, BluetoothGattCharacteristic characteristic) {
                Log.e(TAG, String.format("onCharacteristicReadRequest:device name = %s, address = %s", device.getName(), device.getAddress()));
                Log.e(TAG, String.format("onCharacteristicReadRequest:requestId = %s, offset = %s", requestId, offset));
                bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, characteristic.getValue());
                //            super.onCharacteristicReadRequest(device, requestId, offset, characteristic);
            }
    
            /**
             * 3. onCharacteristicWriteRequest,接收具体的字节
             * @param device
             * @param requestId
             * @param characteristic
             * @param preparedWrite
             * @param responseNeeded
             * @param offset
             * @param requestBytes
             */
            @Override
            public void onCharacteristicWriteRequest(BluetoothDevice device, int requestId, BluetoothGattCharacteristic characteristic, boolean preparedWrite, boolean responseNeeded, int offset, byte[] requestBytes) {
                Log.e(TAG, String.format("3.onCharacteristicWriteRequest:device name = %s, address = %s", device.getName(), device.getAddress()));
                bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, requestBytes);
                //4.处理响应内容
                onResponseToClient(requestBytes, device, requestId, characteristic);
            }
    
            /**
             * 2.描述被写入时,在这里执行 bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS...  收,触发 onCharacteristicWriteRequest
             * @param device
             * @param requestId
             * @param descriptor
             * @param preparedWrite
             * @param responseNeeded
             * @param offset
             * @param value
             */
            @Override
            public void onDescriptorWriteRequest(BluetoothDevice device, int requestId, BluetoothGattDescriptor descriptor, boolean preparedWrite, boolean responseNeeded, int offset, byte[] value) {
                Log.e(TAG, String.format("2.onDescriptorWriteRequest:device name = %s, address = %s", device.getName(), device.getAddress()));
                //            Log.e(TAG, String.format("2.onDescriptorWriteRequest:requestId = %s, preparedWrite = %s, responseNeeded = %s, offset = %s, value = %s,", requestId, preparedWrite, responseNeeded, offset, OutputStringUtil.toHexString(value)));
    
                // now tell the connected device that this was all successfull
                bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, value);
            }
    
            /**
             * 5.特征被读取。当回复响应成功后,客户端会读取然后触发本方法
             * @param device
             * @param requestId
             * @param offset
             * @param descriptor
             */
            @Override
            public void onDescriptorReadRequest(BluetoothDevice device, int requestId, int offset, BluetoothGattDescriptor descriptor) {
                Log.e(TAG, String.format("onDescriptorReadRequest:device name = %s, address = %s", device.getName(), device.getAddress()));
                Log.e(TAG, String.format("onDescriptorReadRequest:requestId = %s", requestId));
                //            super.onDescriptorReadRequest(device, requestId, offset, descriptor);
                bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, null);
            }
    
            @Override
            public void onNotificationSent(BluetoothDevice device, int status) {
                super.onNotificationSent(device, status);
                Log.e(TAG, String.format("5.onNotificationSent:device name = %s, address = %s", device.getName(), device.getAddress()));
                Log.e(TAG, String.format("5.onNotificationSent:status = %s", status));
            }
    
            @Override
            public void onMtuChanged(BluetoothDevice device, int mtu) {
                super.onMtuChanged(device, mtu);
                Log.e(TAG, String.format("onMtuChanged:mtu = %s", mtu));
            }
    
            @Override
            public void onExecuteWrite(BluetoothDevice device, int requestId, boolean execute) {
                super.onExecuteWrite(device, requestId, execute);
                Log.e(TAG, String.format("onExecuteWrite:requestId = %s", requestId));
            }
        };
    

    接收数据

    /**
         * 4.处理响应内容
         *
         * @param reqeustBytes
         * @param device
         * @param requestId
         * @param characteristic
         */
        private void onResponseToClient(byte[] reqeustBytes, BluetoothDevice device, int requestId, BluetoothGattCharacteristic characteristic) {
            Log.e(TAG, String.format("4.onResponseToClient:device name = %s, address = %s", device.getName(), device.getAddress()));
            Log.e(TAG, String.format("4.onResponseToClient:requestId = %s", requestId));
            //        String msg = OutputStringUtil.transferForPrint(reqeustBytes);
            String msg = new String(reqeustBytes);
            println("4.收到:" + msg);
            showText("4.收到:" + msg);
            currentDevice = device;
        }
    

    发送数据

     BluetoothDevice currentDevice;
    
        private void sendMessage(String message) {
            characteristicRead.setValue(message.getBytes());
            if (currentDevice != null)
                bluetoothGattServer.notifyCharacteristicChanged(currentDevice, characteristicRead, false);
    
            println("4.发送:" + message);
            showText("4.发送:" + message);
        }
    

    交互流程:

    (1) 当客户端开始写入数据时: 触发回调方法 onDescriptorWriteRequest

    (2) 在 onDescriptorWriteRequest 方法中,执行下面的方法表示 写入成功 BluetoothGatt.GATT_SUCCESS

       bluetoothGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, value);
    

    执行 sendResponse后,会触发回调方法 onCharacteristicWriteRequest
    (3) 在 onCharacteristicWriteRequest方法中

        public void onCharacteristicWriteRequest(BluetoothDevice device, int requestId, BluetoothGattCharacteristic characteristic, boolean preparedWrite, boolean responseNeeded, int offset, byte[] requestBytes) {
    

    这个里可以获得 来自客户端发来的数据 requestBytes
    (4) 处理响应内容,我写了这个方法:

    onResponseToClient(requestBytes, device, requestId, characteristic);
    

    在这个方法中,通过 bluetoothGattServer.notifyCharacteristicChanged()方法 回复数据

    Android ble低功耗蓝牙开发-客户端
    Android ble低功耗蓝牙开发-服务端
    源码传送门

    参考文章:

    Android BLE 蓝牙开发入门
    Android BLE开发之Android手机与BLE终端通信
    GitHub参考

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