app -- 系统服务 -- bluetooth.apk
关键：
GattService 承接服务注册和回调给服务端
源码
7.1
核心代码
frameworks/base/core/java/android/bluetooth
BluetoothAdapter
BluetoothLeAdvertiser
AdvertiseSettings
AdvertiseData
AdvertiseCallback
BluetoothManager
BluetoothGattServer
BluetoothGattServerCallback
BluetoothGattService
BluetoothGattCharacteristic
packages/apps/Bluetooth/src/com/android/bluetooth/gatt
GattService
AdvertiseManager
1.怎么设置广播
1)应用
private class BLEAdvertiser extends AdvertiseCallback {
private BluetoothLeAdvertiser mBluetoothLeAdvertiser;
public void startAdvertising() {
if(mBluetoothLeAdvertiser == null) {
mBluetoothLeAdvertiser = mBluetoothAdapter.getBluetoothLeAdvertiser();//广播者的来源
}
if (mBluetoothLeAdvertiser == null) {
Slog.w(TAG, "Failed to create advertiser");
return;
}
AdvertiseSettings settings = new AdvertiseSettings.Builder()
.setAdvertiseMode(AdvertiseSettings.ADVERTISE_MODE_LOW_LATENCY)
.setConnectable(true)
.setTimeout(0)
.setTxPowerLevel(AdvertiseSettings.ADVERTISE_TX_POWER_HIGH)
.build();//设置配置
AdvertiseData data = new AdvertiseData.Builder()
.setIncludeDeviceName(true)
.setIncludeTxPowerLevel(false)
.addServiceUuid(new ParcelUuid(SERVICE_UUID))
.build();//设置数据
mBluetoothLeAdvertiser.startAdvertising(settings, data, this);//开始广播。开始是否成功由回调方法给出答复
}
public void stopAdvertising() {
if(mBluetoothLeAdvertiser != null) {
mBluetoothLeAdvertiser.stopAdvertising(this);
}
}
@Override
public void onStartSuccess(AdvertiseSettings settingsInEffect) {//广播设置成功的回调
if(DBG) Slog.v(TAG, "start Advertise Success info="+(settingsInEffect == null ? null : settingsInEffect.toString()));
mState = STATE_ADVERTISE_SUCCESS;
if(mBLEGattServer != null) {
mBLEGattServer.startServer();
}
}
@Override
public void onStartFailure(int errorCode) {//广播设置失败的回调
mState = STATE_ADVERTISE_FAILED;
Slog.e(TAG, "start Advertise failed,errorCode="+errorCode);
}
}
2)源码分析。
案例：BluetoothLeAdvertiser.startAdvertising
a.startAdvertising
public void startAdvertising(AdvertiseSettings settings,
AdvertiseData advertiseData, AdvertiseData scanResponse,
final AdvertiseCallback callback) {
synchronized (mLeAdvertisers) {
······
IBluetoothGatt gatt;
try {
gatt = mBluetoothManager.getBluetoothGatt();
} catch (RemoteException e) {
Log.e(TAG, "Failed to get Bluetooth gatt - ", e);
postStartFailure(callback, AdvertiseCallback.ADVERTISE_FAILED_INTERNAL_ERROR);
return;
}
AdvertiseCallbackWrapper wrapper = new AdvertiseCallbackWrapper(callback, advertiseData,
scanResponse, settings, gatt);
wrapper.startRegisteration();//包装类的注册
}
}
b.AdvertiseCallbackWrapper.startRegisteration
private class AdvertiseCallbackWrapper extends BluetoothGattCallbackWrapper {
public void startRegisteration() {
synchronized (this) {
if (mClientIf == -1) return;
try {
UUID uuid = UUID.randomUUID();
mBluetoothGatt.registerClient(new ParcelUuid(uuid), this);//binder对象跨进程注册，注意回调
wait(LE_CALLBACK_TIMEOUT_MILLIS);//等待
} catch (InterruptedException | RemoteException e) {
Log.e(TAG, "Failed to start registeration", e);
}
······
}
}
/**
* Application interface registered - app is ready to go
*/
@Override
public void onClientRegistered(int status, int clientIf) {//registerClient成功与失败的回调方法
Log.d(TAG, "onClientRegistered() - status=" + status + " clientIf=" + clientIf);
synchronized (this) {
if (status == BluetoothGatt.GATT_SUCCESS) {
try {
if (mClientIf == -1) {
// Registration succeeds after timeout, unregister client.
mBluetoothGatt.unregisterClient(clientIf);
} else {
mClientIf = clientIf;
mBluetoothGatt.startMultiAdvertising(mClientIf, mAdvertisement,
mScanResponse, mSettings);//启动广播
}
return;
} catch (RemoteException e) {
Log.e(TAG, "failed to start advertising", e);
}
}
// Registration failed.
mClientIf = -1;
notifyAll();
}
}
@Override
public void onMultiAdvertiseCallback(int status, boolean isStart,
AdvertiseSettings settings) {
synchronized (this) {
if (isStart) {
if (status == AdvertiseCallback.ADVERTISE_SUCCESS) {
// Start success
mIsAdvertising = true;
postStartSuccess(mAdvertiseCallback, settings);
} else {
// Start failure.
postStartFailure(mAdvertiseCallback, status);
}
} else {
// unregister client for stop.
try {
mBluetoothGatt.unregisterClient(mClientIf);
mClientIf = -1;
mIsAdvertising = false;
mLeAdvertisers.remove(mAdvertiseCallback);
} catch (RemoteException e) {
Log.e(TAG, "remote exception when unregistering", e);
}
}
notifyAll();
}
}
}
c.进入Bluetooth.apk的GattService.registerClient
packages/apps/Bluetooth/
com.android.bluetooth.gatt.GattService
void registerClient(UUID uuid, IBluetoothGattCallback callback) {
enforceCallingOrSelfPermission(BLUETOOTH_PERM, "Need BLUETOOTH permission");
if (DBG) Log.d(TAG, "registerClient() - UUID=" + uuid);
mClientMap.add(uuid, callback, this);
gattClientRegisterAppNative(uuid.getLeastSignificantBits(),
uuid.getMostSignificantBits());//回调的方法，通过jni触发
}
void onClientRegistered(int status, int clientIf, long uuidLsb, long uuidMsb)
throws RemoteException {//jni调用回来的回调方法
UUID uuid = new UUID(uuidMsb, uuidLsb);
if (DBG) Log.d(TAG, "onClientRegistered() - UUID=" + uuid + ", clientIf=" + clientIf);
ClientMap.App app = mClientMap.getByUuid(uuid);
if (app != null) {
if (status == 0) {
app.id = clientIf;
app.linkToDeath(new ClientDeathRecipient(clientIf));
} else {
mClientMap.remove(uuid);
}
app.callback.onClientRegistered(status, clientIf);//binder对象跨进程调回注册app
}
}
d.进入Bluetooth.apk的GattService.startMultiAdvertising
packages/apps/Bluetooth/
com.android.bluetooth.gatt.GattService
void startMultiAdvertising(int clientIf, AdvertiseData advertiseData,
AdvertiseData scanResponse, AdvertiseSettings settings) {
enforceAdminPermission();
mAdvertiseManager.startAdvertising(new AdvertiseClient(clientIf, settings, advertiseData,
scanResponse));
}
packages/apps/Bluetooth/
com.android.bluetooth.gatt.AdvertiseManager
void startAdvertising(AdvertiseClient client) {
if (client == null) {
return;
}
Message message = new Message();
message.what = MSG_START_ADVERTISING;
message.obj = client;
mHandler.sendMessage(message);
}
private void handleStartAdvertising(AdvertiseClient client) {
Utils.enforceAdminPermission(mService);
int clientIf = client.clientIf;
······
if (!mAdvertiseNative.startAdverising(client)) {//jni注册
postCallback(clientIf, AdvertiseCallback.ADVERTISE_FAILED_INTERNAL_ERROR);
return;
}
mAdvertiseClients.add(client);
postCallback(clientIf, AdvertiseCallback.ADVERTISE_SUCCESS);//回调成功
}
// Post callback status to app process.
private void postCallback(int clientIf, int status) {
try {
AdvertiseClient client = getAdvertiseClient(clientIf);
AdvertiseSettings settings = (client == null) ? null : client.settings;
boolean isStart = true;
mService.onMultipleAdvertiseCallback(clientIf, status, isStart, settings);//回调到GattService
} catch (RemoteException e) {
loge("failed onMultipleAdvertiseCallback", e);
}
}
packages/apps/Bluetooth/
com.android.bluetooth.gatt.GattService
// callback from AdvertiseManager for advertise status dispatch.
void onMultipleAdvertiseCallback(int clientIf, int status, boolean isStart,
AdvertiseSettings settings) throws RemoteException {
ClientMap.App app = mClientMap.getById(clientIf);
if (app == null || app.callback == null) {
Log.e(TAG, "Advertise app or callback is null");
return;
}
app.callback.onMultiAdvertiseCallback(status, isStart, settings);//binder通信调进注册app
}
e.小结
亮点1：
Bluetooth.apk中的GattService既作为app跨进程调用的接收方，也作为回调方法回调的处理方。这种接收和回调处理集中处理，方便了代码阅读。点赞
亮点2：
IBluetoothGattCallback中涉及的方法很多，在客户端调用时，采用了BluetoothGattCallbackWrapper模式，这样继承BluetoothGattCallbackWrapper的类，就不用全部把方法类出来。点赞
class BluetoothGattCallbackWrapper extends IBluetoothGattCallback.Stub
class AdvertiseCallbackWrapper extends BluetoothGattCallbackWrapper