android藍(lán)牙簡(jiǎn)單開(kāi)發(fā)示例教程

更新時(shí)間：2021年12月08日 14:12:29 作者：東東旭huster

大家好，本篇文章主要講的是android藍(lán)牙簡(jiǎn)單開(kāi)發(fā)示例教程，感興趣的同學(xué)趕快來(lái)看一看吧，對(duì)你有幫助的話記得收藏一下

概述

前段時(shí)間學(xué)習(xí)了一些藍(lán)牙開(kāi)發(fā)的知識(shí)，記錄一下Android中藍(lán)牙的簡(jiǎn)單開(kāi)發(fā)。下面是最重要的兩個(gè)類。

BluetoothAdapter : 藍(lán)牙適配器，通過(guò)getDefaultAdapter ()去獲取一個(gè)實(shí)例，如果設(shè)備不支持藍(lán)牙的話，返回的是一個(gè)null對(duì)象，通過(guò)它，可以打開(kāi)、關(guān)閉藍(lán)牙，掃描設(shè)備、向指定設(shè)備創(chuàng)建socket通道…

BluetoothDevice : 代表一個(gè)設(shè)備對(duì)象，可以通過(guò)它獲取設(shè)備的名字、地址、類型等，也可以創(chuàng)建匹配，建立socket通道等等。

1、權(quán)限申請(qǐng)

<uses-permission android:name="android.permission.BLUETOOTH"/> 使用藍(lán)牙所需要的權(quán)限
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/> 使用掃描和設(shè)置藍(lán)牙的權(quán)限（申明這一個(gè)權(quán)限必須申明上面一個(gè)權(quán)限）

Android6以上版本，掃描其他藍(lán)牙還需要位置權(quán)限

// Android 9 以下版本
<user-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 
// Android 9 以上
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

2、打開(kāi)藍(lán)牙

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// 如果設(shè)備不支持藍(lán)牙
if (mBluetoothAdapter == null){
    return;
}
// 設(shè)備支持藍(lán)牙功能，調(diào)用startActivityForResult去啟動(dòng)藍(lán)牙
if (!mBluetoothAdapter.isEnabled()){
    startBlueTooth.launch(new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE));
}

打開(kāi)藍(lán)牙功能是通過(guò)startActivity去啟動(dòng)的，但是startActivity這個(gè)函數(shù)已經(jīng)過(guò)期了，所以我使用官方推薦的Activity Result替代它

    ActivityResultLauncher<Intent> startBlueTooth = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
            new ActivityResultCallback<ActivityResult>() {
                @Override
                public void onActivityResult(ActivityResult result) {
                    if (result==null){
                        Toast.makeText(BlueToothActivity.this, "open failed", Toast.LENGTH_SHORT).show();
                    }else {
                        if (result.getResultCode() == RESULT_CANCELED){
                            Toast.makeText(BlueToothActivity.this,"用戶取消",Toast.LENGTH_SHORT);
                        }
                    }
                }
            });

3、接收藍(lán)牙狀態(tài)的改變

通過(guò)廣播去接收藍(lán)牙狀態(tài)的改變

class BluetoothStateChangeReceiver extends BroadcastReceiver{
    public int DEFAULT_VALUE_BLUETOOTH = 1000;

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)){
            int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,DEFAULT_VALUE_BLUETOOTH);

            switch(state){
                case BluetoothAdapter.STATE_ON:
                    Log.d(TAG, "onReceive: open");
                    break;
                case BluetoothAdapter.STATE_OFF:
                    Log.d(TAG, "onReceive: off");
                    break;
                case BluetoothAdapter.STATE_TURNING_ON :
                    Log.d(TAG, "onReceive: 正在打開(kāi)");
                    break;
                case BluetoothAdapter.STATE_TURNING_OFF:
                    Log.d(TAG, "onReceive: 正在關(guān)閉");
                    break;
            }
        }
    }
}

別忘了廣播的注冊(cè)和解注冊(cè)

IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
stateReceiver = new BluetoothStateChangeReceiver() ;
registerReceiver(stateReceiver,filter);

4、掃描其他的設(shè)備

同樣通過(guò)廣播接收，action是BluetoothDevice.ACTION_FOUND

    class MyReceiver extends BroadcastReceiver{
        @Override
        public void onReceive(Context context, Intent intent) {

            String action = intent.getAction();

            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // 從intent對(duì)象中獲取藍(lán)牙設(shè)備的信息
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // 當(dāng)發(fā)現(xiàn)新設(shè)備不存在于配對(duì)列表中時(shí)添加
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    blueNames.add(device.getName()+"\t"+device.getAddress());
                }
                blueAdpater.notifyDataSetChanged();
                Log.d(TAG, "onReceive: " + device.getName());
            }
        }
    }

動(dòng)態(tài)注冊(cè)廣播

IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver,filter);

開(kāi)啟掃描

mBluetoothAdapter.startDiscovery();

5、藍(lán)牙配對(duì)

    public class BondReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(intent.getAction())){
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                switch(device.getBondState()){
                    case BluetoothDevice.BOND_BONDED:
                        Log.d(TAG, "onReceive: 配對(duì)完成");
                        break;
                    case BluetoothDevice.BOND_BONDING:
                        Log.d(TAG, "onReceive: 正在配對(duì)");
                        break;
                    case BluetoothDevice.BOND_NONE:
                        Log.d(TAG, "onReceive: 取消配對(duì)");
                        break;
                }
            }
        }
    }

6、獲取已經(jīng)配對(duì)的設(shè)備

已經(jīng)配對(duì)的設(shè)備會(huì)被存儲(chǔ)起來(lái)，通過(guò)BluetoothAdpater直接獲取即可

Set<BluetoothDevice> paireDevices = mBluetoothAdapter.getBondedDevices();
if (paireDevices.size()>0){
                        for (BluetoothDevice pairedDevice : pairedDevices) {
                        blueNames.add(pairedDevice.getName()+"  "+pairedDevice.getAddress());
                        Log.d(TAG, "onClick: "+pairedDevice.getName());
                    }
}

7、連接設(shè)備

想要在兩臺(tái)設(shè)備之間創(chuàng)建連接，必須實(shí)現(xiàn)客戶端和服務(wù)端機(jī)制，他們之間使用套接字機(jī)制進(jìn)行連接，服務(wù)端開(kāi)放服務(wù)器套接字，客戶端通過(guò)MAC地址向服務(wù)端發(fā)起連接。客戶端和服務(wù)端以不同的方式獲得BluetoothSocket,當(dāng)客戶端和服務(wù)端在同一個(gè)RFCOMM通道上分別擁有已連接的BluetoothSocket時(shí)，將他們視為彼此已經(jīng)連接，于是每臺(tái)設(shè)備都獲得輸入和輸出流式傳輸，并開(kāi)始傳輸數(shù)據(jù)。

連接技術(shù)

一種實(shí)現(xiàn)技術(shù)是自動(dòng)將每臺(tái)設(shè)備準(zhǔn)備為一個(gè)服務(wù)器，從而使每臺(tái)設(shè)備開(kāi)放一個(gè)服務(wù)套接字并偵聽(tīng)連接，在此情況下，任何一臺(tái)設(shè)備都可以發(fā)起與另一臺(tái)設(shè)備的連接并稱為客戶端。

服務(wù)器

設(shè)置服務(wù)器套接字并接受連接，步驟依次如下

1、調(diào)用listenUsingRfcommWithServiceRecord（）獲取一個(gè)BluetoothServerSocket, 該函數(shù)需要兩個(gè)參數(shù)，第一個(gè)是服務(wù)器的名稱，自己取一個(gè)即可，第二個(gè)是UUID，用來(lái)對(duì)信息做唯一性標(biāo)識(shí)，我們可以從網(wǎng)上眾多UUID生成器中隨機(jī)的生成一個(gè)，然后使用UUID.fromString(String)初始化一個(gè)UUID。

2、通過(guò)accept()函數(shù)開(kāi)始偵聽(tīng)連接請(qǐng)求

只有遠(yuǎn)程設(shè)備發(fā)送的連接請(qǐng)求中UUID與使用此套接字注冊(cè)的UUID相匹配時(shí)服務(wù)器才會(huì)接受請(qǐng)求，accept函數(shù)會(huì)返回已連接的BluetoothSocket

3、連接成功后調(diào)用close()關(guān)閉BluetoothSocket

 private class AcceptThread extends Thread{

        private final BluetoothServerSocket mmServerSocket;
        private String mSocketType;

        public AcceptThread(boolean secure){
            BluetoothServerSocket tmp = null;
            mSocketType = secure ? "secure" : "Insercure";
            try{
                if (secure){
                    tmp = bluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE,MY_UUID_SECURE);
                }else{
                    tmp = bluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME_INSECURE,MY_UUID_INSECURE);
                }
            } catch (IOException e) {
                Log.e(TAG,"socket type"+ mSocketType + "listen() failed",e);
            }

            mmServerSocket = tmp;
        }

        @Override
        public void run() {
            Log.d(TAG, "Socket Type: " + mSocketType +
                    "BEGIN mAcceptThread" + this);
            setName("AcceptThread"+ mSocketType);

            BluetoothSocket socket = null;
            Log.d(TAG, "run: 開(kāi)始監(jiān)聽(tīng)");
            while (true){
                try{
                    socket = mmServerSocket.accept();
                    Log.d("acceptThread", "run: 連接成功");
                    connected(socket,socket.getRemoteDevice(),mSocketType);
                } catch (IOException e) {
                    Log.e(TAG, "Socket Type: " + mSocketType + "accept() failed", e);
                    break;
                }

            }
            Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType);
        }

        public void cancel() {
            Log.d(TAG, "Socket Type" + mSocketType + "cancel " + this);
            try {
                mmServerSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);
            }
        }
    }

上面的secure和Insecure只是使用了不同的UUID而已。

客戶端

遠(yuǎn)程設(shè)備開(kāi)啟監(jiān)聽(tīng)后，我們就發(fā)起向此設(shè)備的連接，首先必須先獲得遠(yuǎn)程設(shè)備的BluetoothDevice對(duì)象，然后獲取BluetoothSocket發(fā)起連接。

基本步驟如下

1、使用BluetoothDevice通過(guò)調(diào)用createRfcommSocketToServiceRecord(UUID) 獲取 BluetoothSocket。

2、通過(guò)connect發(fā)起連接

private class ConnectThread extends Thread{
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
        private String mSocketType;

        public ConnectThread(BluetoothDevice device, boolean secure){
            mmDevice = device;
            BluetoothSocket tmp = null;
            mSocketType = secure ? "Secure" : "Insecure";
            try {
                if (secure){
                    tmp = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE);
                }else {
                    tmp = device.createRfcommSocketToServiceRecord(MY_UUID_INSECURE);
                }
            } catch (IOException e) {
                Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e);
            }
            mmSocket = tmp;
        }

        @Override
        public void run() {
            Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType);
            setName("ConnectThred"+mSocketType);

            // 總是取消發(fā)現(xiàn)，因?yàn)樗鼤?huì)減慢連接
            bluetoothAdapter.cancelDiscovery();
            // connect
            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mmSocket.connect();
                Log.d(TAG, "run: socket連接成功");
            } catch (IOException e) {
                // Close the socket
                Log.d(TAG, "run: 關(guān)閉socket");
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                    Log.e(TAG, "unable to close() " + mSocketType +
                            " socket during connection failure", e2);
                }

                return;
            }

            connected(mmSocket,mmDevice,mSocketType);
        }

        public void cancel(){
            try{
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e);
            }
        }

    }

發(fā)送數(shù)據(jù)

連接成功后，我們就可以通過(guò)socket發(fā)送數(shù)據(jù)了，客戶端的Socket對(duì)象是BluetoothSocket, 服務(wù)端的socket是BluetoothServerSocket，特別注意不要混淆了。使用getInputStream和getOutputStream分別獲取通過(guò)套接字處理數(shù)據(jù)傳輸?shù)?code>InputStream和OutputStream。寫數(shù)據(jù)比較簡(jiǎn)單，但是讀數(shù)據(jù)就需要一個(gè)單獨(dú)的線程一直監(jiān)聽(tīng)才行。

private class ConnectedThread extends Thread{
        private final BluetoothSocket mmSocket;
        private InputStream mmInStream;
        private OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket, String socketType) throws IOException {
            Log.d(TAG, "create ConnectedThread: " + socketType);
            mmSocket = socket;

            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            try{
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();

                if (socket != null){
                    tmpOut.write(new String("hello").getBytes());
                    Log.d(TAG, "ConnectedThread: socket不是null");
                }
            } catch (IOException e) {
                Log.e(TAG,"temp socket not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;

            // mmOutStream.write(new String("hello").getBytes());
        }

        @RequiresApi(api = Build.VERSION_CODES.KITKAT)
        @Override
        public void run() {
            Log.i(TAG, "BEGIN mConnectedThread");
            byte[] buffer = new byte[1024];
            int bytes;

            while (true){
                try{
                    bytes = mmInStream.read(buffer);
                    // send the bytes to the ui Activity
                    String text = encodeByteToString(buffer,bytes);
                    Log.d(TAG, "run: 收到消息："+ text);
                    chatItems.add(text);
                    mHandler.sendMessage(mHandler.obtainMessage());
                } catch (IOException e) {
                    Log.d(TAG, "run: 沒(méi)有收到消息");
                    e.printStackTrace();
                    break;
                }
            }
        }

        public String encodeByteToString(byte[] data,int length) {
            byte[] temp = new byte[length];
            for (int i = 0; i < length; i++) {
                temp[i] = data[i];
            }
            try {
                return new String(temp,"utf-8");
            } catch (UnsupportedEncodingException e) {
                return "";
            }
        }


        public void write(byte[] buffer){
            try{
                mmOutStream.write(buffer);

                // mHandler.obtainMessage(Constants.MESSAGE_WRITE,-1,-1,buffer).sendToTarget();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void cancel(){
            try{
                mmSocket.close();
                Log.d(TAG, "cancel: connectedThread");
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }

上面的例子我主要是學(xué)習(xí)官網(wǎng)上的藍(lán)牙聊天項(xiàng)目寫的代碼，大家也可以直接看官網(wǎng)項(xiàng)目。從上面的例子中可知，接受到的數(shù)據(jù)流都是一些二進(jìn)制，要用到實(shí)際的項(xiàng)目中還需要進(jìn)行一定的編碼和轉(zhuǎn)換。也就是自己編寫一些協(xié)議，學(xué)過(guò)socket編程的同學(xué)一定都懂，其實(shí)藍(lán)牙已經(jīng)有很多的好用的協(xié)議了，就比如AVRCP（Audio Video Remote Control Profile），定義了藍(lán)牙設(shè)備和audio/video控制功能通信的特點(diǎn)和過(guò)程, 結(jié)合MediaSession 可以很容易的實(shí)現(xiàn)設(shè)備音視頻控制。

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