最近项目里面需要集成一个蓝牙的连接功能，作为一枚刚刚毕业不久的新生，大学几年又白过的。只好在几天内搜搜百度，脑补一下。文章部分内容摘至各大Blog，加上本dust的见解，写了一份Client端和Service端的小呆毛。
这次的是Server端的实现
参考链接–Link:http://www.cnblogs.com/vir56k/p/6273241.html
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上次聊过Gatt协议，以及几个API的使用并实现了Client端的代码。这次实现的是Server端，不叨叨，show me the code
**
一、Server端概念了解
**
之前说了Client端，这次Server端，Server端的实现比较简单。只是多了一个类似广播的东西，叫BluetoothLeAdvertiser，翻译广告…我还是用广播感觉合适点。Server端需要发射出广播，同时Server会暴露一个数据包出去。当Client开始扫描，Client扫描到Server端的数据包之后，就会请求连接。Server就做出反应，然后连接，开始传输数据。
**
二、API分析
**
当前使用到的类包括：
BluetoothManager
BluetoothAdapter
BluetoothService
BluetoothGattCharacteristic
BluetoothServer
BluetoothAdvertiser
AdvertiseSetting
AdvertiseData
BluetoothGattServerCallback
BluetoothManager，BluetoothService，BluetoothAdapter，BluetoothGattCharacteristic之前都说过了，可能需要补充的是BluetoothManager的一个API。
BluetoothManager.openGattServer
其他的，忘了的童鞋可以参考上一章 Android Ble蓝牙开发（客户端）
那么我就说下下面四个新的API
BluetoothServer
我也想不到，Android是直接给出这样的一个Server的API可以供我们操作。这里的Server大家需要和Service区分，一个是服务器端，一个是Service服务。类似Android系统提供出形形色色的那些服务。
这里的猜测IPC其实是Application与蓝牙件程序的通信。我也没作深究了
BluetoothAdvertiser
服务器广播，用于开启服务器广播以供Client端扫描发现
AdvertiseSetting
这个类的创建需要用到Builder，其作用是设置Advertiser属性的，例如广播的Mode，连接时间，连接可用等等。
AdvertiseData
这个类的作用就是配置广播的数据的，例如设置服务的UUID，传输的等级TxPowerLevel，还有设置设备名是否包含在传输数据里面。
BluetoothGattServerCallback
这个接口里面实现的几个方法比较关键，里面有连接状态的回调,Client离服务器的距离RSSI，收到characteristic操作的请求回调，还有descriptor操作的请求回调等等。最关键的地方就是，我们收到了关于Characteristic和descriptor的操作请求的时候，都必须调用 BluetoothGattServer.sendResponse(BluetoothDevice device, int requestId,int status,int offset,byte[] value) 方法才能完成整个连接过程
**
三、代码实现
**
实现思路大概如下：
1.设置广播以及初始化广播数据
2.开始广播
3.配置Services以及Characteristic
4.Server回调以及操作
设置广播以及初始化广播数据
/**
* 1.初始化BLE蓝牙广播Advertiser，配置指定UUID的服务
*/
@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();
//通过UUID_SERVICE构建
AdvertiseData scanResponseData = new AdvertiseData.Builder()
.addServiceUuid(new ParcelUuid(Const.UUID_SERVICE))
.setIncludeTxPowerLevel(true)
.build();
//广播创建成功之后的回调
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");
//初始化服务
initServices(BleService.this);
}
@Override
public void onStartFailure(int errorCode) {
Log.e(TAG, "Failed to add BLE advertisement, reason: " + errorCode);
//showText("1. initGATTServer failure");
}
};
//部分设备不支持Ble中心
BluetoothLeAdvertiser bluetoothLeAdvertiser = mBlueToothAdapter.getBluetoothLeAdvertiser();
if (bluetoothLeAdvertiser == null) {
Log.i(TAG, "BluetoothLeAdvertiser为null");
}
//开始广播
if (bluetoothLeAdvertiser != null) {
bluetoothLeAdvertiser.startAdvertising(settings, advertiseData, scanResponseData, callback);
}
}配置Services以及Characteristic
/**
* 初始化Gatt服务，主要是配置Gatt服务各种UUID
*
* @param context
*/
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
private void initServices(Context context) {
//创建GattServer服务器
mGattServer = mBluetoothManager.openGattServer(context, bluetoothGattServerCallback);
//这个指定的创建指定UUID的服务
BluetoothGattService service = new BluetoothGattService(Const.UUID_SERVICE, BluetoothGattService.SERVICE_TYPE_PRIMARY);
//添加指定UUID的可读characteristic
characteristicRead = new BluetoothGattCharacteristic(
Const.UUID_CHARACTERISTIC_READ,
BluetoothGattCharacteristic.PROPERTY_READ,
BluetoothGattCharacteristic.PERMISSION_READ);
//添加可读characteristic的descriptor
BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(UUID_DESCRIPTOR, BluetoothGattCharacteristic.PERMISSION_WRITE);
characteristicRead.addDescriptor(descriptor);
service.addCharacteristic(characteristicRead);
//添加指定UUID的可写characteristic
BluetoothGattCharacteristic characteristicWrite = new BluetoothGattCharacteristic(Const.UUID_CHARACTERISTIC_WRITE,
BluetoothGattCharacteristic.PROPERTY_WRITE |
BluetoothGattCharacteristic.PROPERTY_READ |
BluetoothGattCharacteristic.PROPERTY_NOTIFY,
BluetoothGattCharacteristic.PERMISSION_WRITE);
service.addCharacteristic(characteristicWrite);
mGattServer.addService(service);
Log.e(TAG, "2. initServices ok");
//showText("2. initServices ok");
}到这里，Server的配置算是完成了。之后就是等待BluetoothGattServerCallback的回调了
Server回调以及操作
/**
* 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);
}
@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));
mGattServer.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()));
Log.e(TAG, String.format("3.onCharacteristicWriteRequest：requestId = %s, preparedWrite=%s, responseNeeded=%s, offset=%s, value=%s", requestId, preparedWrite, responseNeeded, offset, requestBytes.toString()));
mGattServer.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, value.toString()));
// now tell the connected device that this was all successfull
mGattServer.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);
mGattServer.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));
}
};
/**
* 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);
Log.e(TAG, "4.收到：");
//println("4.收到:" + msg);
//showText("4.收到:" + msg);
String str = new String(reqeustBytes) + " hello>";
characteristicRead.setValue(str.getBytes());
mGattServer.notifyCharacteristicChanged(device, characteristicRead, false);
Log.i(TAG, "4.响应：" + str);
MainActivity.handler.obtainMessage(MainActivity.DEVICE, new String(reqeustBytes)).sendToTarget();
//println("4.响应:" + str);
//showText("4.响应:" + str);
}上面代码中需要注意的地方是，当我们收到了Characteristic和Descriptor操作请求后，一定需要调用BluetoothGattServer.sendResponse(BluetoothDevice device, int requestId,int status,int offset,byte[] value) 方法才能完成整个连接过程。
onResponseToClient
我们在onCharacteristicWriteRequest回调里面对数据进行了提取，然后还需要调用BluetoothGattServer.notifyCharacteristicChanged(device, characteristic, false) 通知Client端Characteristic已经发生了变化。
/**
* 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);
Log.e(TAG, "4.收到：");
//println("4.收到:" + msg);
//showText("4.收到:" + msg);
String str = new String(reqeustBytes) + " hello>";
/* characteristicRead.setValue(str.getBytes());
mGattServer.notifyCharacteristicChanged(device, characteristicRead, false);*/
characteristic.setValue(str.getBytes());
mGattServer.notifyCharacteristicChanged(device, characteristic, false);
Log.i(TAG, "4.响应：" + str);
MainActivity.handler.obtainMessage(MainActivity.DEVICE, new String(reqeustBytes)).sendToTarget();
//println("4.响应:" + str);
//showText("4.响应:" + str);
}
到上面为止，BLE两demo已经完成了，不过服务器端的Manifest也需要配置，和BleClient一样就好了。同时注意操作最好都放到Service中完成。下面放个源码，希望大家多多支持吧~
源码下载