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Android 蓝牙开发浅析

發布時間：2024/4/15 Android 34 豆豆

生活随笔收集整理的這篇文章主要介紹了 Android 蓝牙开发浅析小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

Android Bluetooth API 翻譯http://wenku.baidu.com/view/518414b069dc5022aaea007b.html?from=rec&pos=2&weight=167&lastweight=111&count=5

由于近期正在開發一個通過藍牙進行數據傳遞的模塊，在參考了有關資料，并詳細閱讀了Android的官方文檔后，總結了Android中藍牙模塊的使用。

1. 使用藍牙的響應權限

查看源碼打印?

1	<STRONG>??? <uses-permission android:name="android.permission.BLUETOOTH" />??

2	????<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />? </STRONG>

2. 配置本機藍牙模塊

在這里首先要了解對藍牙操作一個核心類BluetoothAdapter

查看源碼打印?

01	BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();??

02	//直接打開系統的藍牙設置面板??

03	Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);??

04	startActivityForResult(intent, 0x1);??

05	//直接打開藍牙??

06	adapter.enable();??

//關閉藍牙??

08	adapter.disable();??

09	//打開本機的藍牙發現功能（默認打開120秒，可以將時間最多延長至300秒）??

10	discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);//設置持續時間（最多300秒）Intent discoveryIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);

3.搜索藍牙設備

使用BluetoothAdapter的startDiscovery()方法來搜索藍牙設備

startDiscovery()方法是一個異步方法，調用后會立即返回。該方法會進行對其他藍牙設備的搜索，該過程會持續12秒。該方法調用后，搜索過程實際上是在一個System Service中進行的，所以可以調用cancelDiscovery()方法來停止搜索（該方法可以在未執行discovery請求時調用）。

請求Discovery后，系統開始搜索藍牙設備，在這個過程中，系統會發送以下三個廣播：

ACTION_DISCOVERY_START：開始搜索

ACTION_DISCOVERY_FINISHED：搜索結束

ACTION_FOUND：找到設備，這個Intent中包含兩個extra fields：EXTRA_DEVICE和EXTRA_CLASS，分別包含BluetooDevice和BluetoothClass。

我們可以自己注冊相應的BroadcastReceiver來接收響應的廣播，以便實現某些功能

查看源碼打印?

01	// 創建一個接收ACTION_FOUND廣播的BroadcastReceiver??

02	private final BroadcastReceiver mReceiver = new BroadcastReceiver() {??

03	????public void onReceive(Context context, Intent intent) {??

04	????????String action = intent.getAction();??

05	????????// 發現設備??

06	????????if (BluetoothDevice.ACTION_FOUND.equals(action)) {??

07	????????????// 從Intent中獲取設備對象??

08	????????????BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);??

09	????????????// 將設備名稱和地址放入array adapter，以便在ListView中顯示??

10	????????????mArrayAdapter.add(device.getName() + "\n" + device.getAddress());??

11	????????}??

????}??

};??

14	// 注冊BroadcastReceiver??

15	IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);??

16	registerReceiver(mReceiver, filter); // 不要忘了之后解除綁定

4. 藍牙Socket通信

如果打算建議兩個藍牙設備之間的連接，則必須實現服務器端與客戶端的機制。當兩個設備在同一個RFCOMM channel下分別擁有一個連接的BluetoothSocket，這兩個設備才可以說是建立了連接。

服務器設備與客戶端設備獲取BluetoothSocket的途徑是不同的。服務器設備是通過accepted一個incoming connection來獲取的，而客戶端設備則是通過打開一個到服務器的RFCOMM channel來獲取的。

服務器端的實現

通過調用BluetoothAdapter的listenUsingRfcommWithServiceRecord(String, UUID)方法來獲取BluetoothServerSocket（UUID用于客戶端與服務器端之間的配對）

調用BluetoothServerSocket的accept()方法監聽連接請求，如果收到請求，則返回一個BluetoothSocket實例（此方法為block方法，應置于新線程中）

如果不想在accept其他的連接，則調用BluetoothServerSocket的close()方法釋放資源（調用該方法后，之前獲得的BluetoothSocket實例并沒有close。但由于RFCOMM一個時刻只允許在一條channel中有一個連接，則一般在accept一個連接后，便close掉BluetoothServerSocket）

查看源碼打印?

01	private class AcceptThread extends Thread {

02	????private final BluetoothServerSocket mmServerSocket;

04	????public AcceptThread() {

05	????????// Use a temporary object that is later assigned to mmServerSocket,

06	????????// because mmServerSocket is final

07	????????BluetoothServerSocket tmp = null;

08	????????try {

09	????????????// MY_UUID is the app's UUID string, also used by the client code

10	????????????tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);

11	????????} catch (IOException e) { }

12	????????mmServerSocket = tmp;

????}

15	????public void run() {

16	????????BluetoothSocket socket = null;

17	????????// Keep listening until exception occurs or a socket is returned

18	????????while (true) {

19	????????????try {

20	????????????????socket = mmServerSocket.accept();

21	????????????} catch (IOException e) {

22	????????????????break;

23	????????????}

24	????????????// If a connection was accepted

25	????????????if (socket != null) {

26	????????????????// Do work to manage the connection (in a separate thread)

27	????????????????manageConnectedSocket(socket);

28	????????????????mmServerSocket.close();

29	????????????????break;

30	????????????}

????????}

????}

34	????/** Will cancel the listening socket, and cause the thread to finish */

35	????public void cancel() {

36	????????try {

37	????????????mmServerSocket.close();

38	????????} catch (IOException e) { }

????}

}

客戶端的實現

通過搜索得到服務器端的BluetoothService

調用BluetoothService的listenUsingRfcommWithServiceRecord(String, UUID)方法獲取BluetoothSocket（該UUID應該同于服務器端的UUID）

調用BluetoothSocket的connect()方法（該方法為block方法），如果UUID同服務器端的UUID匹配，并且連接被服務器端accept，則connect()方法返回

注意：在調用connect()方法之前，應當確定當前沒有搜索設備，否則連接會變得非常慢并且容易失敗

查看源碼打印?

01	<STRONG>??? private class ConnectThread extends Thread {??

02	????????private final BluetoothSocket mmSocket;??

03	????????private final BluetoothDevice mmDevice;??

????????

05	????????public ConnectThread(BluetoothDevice device) {??

06	????????????// Use a temporary object that is later assigned to mmSocket,??

07	????????????// because mmSocket is final??

08	????????????BluetoothSocket tmp = null;??

09	????????????mmDevice = device;??

????????

11	????????????// Get a BluetoothSocket to connect with the given BluetoothDevice??

12	????????????try {??

13	????????????????// MY_UUID is the app's UUID string, also used by the server code??

14	????????????????tmp = device.createRfcommSocketToServiceRecord(MY_UUID);??

15	????????????} catch (IOException e) { }??

16	????????????mmSocket = tmp;??

17	????????}??

????????

19	????????public void run() {??

20	????????????// Cancel discovery because it will slow down the connection??

21	????????????mBluetoothAdapter.cancelDiscovery();??

????????

23	????????????try {??

24	????????????????// Connect the device through the socket. This will block??

25	????????????????// until it succeeds or throws an exception??

26	????????????????mmSocket.connect();??

27	????????????} catch (IOException connectException) {??

28	????????????????// Unable to connect; close the socket and get out??

29	????????????????try {??

30	????????????????????mmSocket.close();??

31	????????????????} catch (IOException closeException) { }??

32	????????????????return;??

33	????????????}??

????????

35	????????????// Do work to manage the connection (in a separate thread)??

36	????????????manageConnectedSocket(mmSocket);??

37	????????}??

????????

39	????????/** Will cancel an in-progress connection, and close the socket */??

40	????????public void cancel() {??

41	????????????try {??

42	????????????????mmSocket.close();??

43	????????????} catch (IOException e) { }??

44	????????}??

45	????}? </STRONG>

連接管理（數據通信）

分別通過BluetoothSocket的getInputStream()和getOutputStream()方法獲取InputStream和OutputStream

使用read(bytes[])和write(bytes[])方法分別進行讀寫操作

注意：read(bytes[])方法會一直block，知道從流中讀取到信息，而write(bytes[])方法并不是經常的block（比如在另一設備沒有及時read或者中間緩沖區已滿的情況下，write方法會block）

查看源碼打印?

01	<STRONG>??? private class ConnectedThread extends Thread {??

02	????????private final BluetoothSocket mmSocket;??

03	????????private final InputStream mmInStream;??

04	????????private final OutputStream mmOutStream;??

????????

06	????????public ConnectedThread(BluetoothSocket socket) {??

07	????????????mmSocket = socket;??

08	????????????InputStream tmpIn = null;??

09	????????????OutputStream tmpOut = null;??

????????

11	????????????// Get the input and output streams, using temp objects because??

12	????????????// member streams are final??

13	????????????try {??

14	????????????????tmpIn = socket.getInputStream();??

15	????????????????tmpOut = socket.getOutputStream();??

16	????????????} catch (IOException e) { }??

????????

18	????????????mmInStream = tmpIn;??

19	????????????mmOutStream = tmpOut;??

20	????????}??

????????

22	????????public void run() {??

23	????????????byte[] buffer = new byte[1024];? // buffer store for the stream??

24	????????????int bytes; // bytes returned from read()??

????????

26	????????????// Keep listening to the InputStream until an exception occurs??

27	????????????while (true) {??

28	????????????????try {??

29	????????????????????// Read from the InputStream??

30	????????????????????bytes = mmInStream.read(buffer);??

31	????????????????????// Send the obtained bytes to the UI Activity??

32	????????????????????mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)??

33	????????????????????????????.sendToTarget();??

34	????????????????} catch (IOException e) {??

35	????????????????????break;??

36	????????????????}??

37	????????????}??

38	????????}??

????????

40	????????/* Call this from the main Activity to send data to the remote device */??

41	????????public void write(byte[] bytes) {??

42	????????????try {??

43	????????????????mmOutStream.write(bytes);??

44	????????????} catch (IOException e) { }??

45	????????}??

????????

47	????????/* Call this from the main Activity to shutdown the connection */??

48	????????public void cancel() {??

49	????????????try {??

50	????????????????mmSocket.close();??

51	????????????} catch (IOException e) { }??

52	????????}??

53	????}? </STRONG>

轉自：http://blog.csdn.net/gd920129/article/details/7487761

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