從查詢藍芽裝置到能夠相互通訊要經過幾個基本步驟(本機做為伺服器)
從查詢藍芽裝置到能夠相互通訊要經過幾個基本步驟(本機做為伺服器)：
1.設定許可權
在manifest中配置
<uses-permission android:name=“android.permission.BLUETOOTH”/+>
<uses-permission android:name=“android.permission.BLUETOOTH_ADMIN”/+>
2.啟動藍芽
首先要檢視本機是否支援藍芽，獲取BluetoothAdapter藍芽介面卡物件
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBluetoothAdapter == null){
//表明此手機不支援藍芽
return;
}
if(!mBluetoothAdapter.isEnabled()){ //藍芽未開啟，則開啟藍芽
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
}
//…
public void onActivityResult(int requestCode, int resultCode, Intent data){
if(requestCode == REQUEST_ENABLE_BT){
if(requestCode == RESULT_OK){
//藍芽已經開啟
}
}
}
3。發現藍芽裝置
這裡可以細分為幾個方面
(1)使本機藍芽處於可見(即處於易被搜尋到狀態)，便於其他裝置發現本機藍芽
//使本機藍芽在300秒內可被搜尋
private void ensureDiscoverable() {
if (mBluetoothAdapter.getScanMode() !=
BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
}
}
(2)查詢已經配對的藍芽裝置，即以前已經配對過的裝置
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices(); if (pairedDevices.size() > 0) { findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE); for (BluetoothDevice device : pairedDevices) { //device.getName() +" "+ device.getAddress()); } } else { mPairedDevicesArrayAdapter.add("沒有找到已匹對的裝置"); }
(3)通過mBluetoothAdapter.startDiscovery();搜尋裝置，要獲得此搜尋的結果需要註冊
一個BroadcastReceiver來獲取。先註冊再獲取資訊，然後處理
//註冊，當一個裝置被發現時呼叫onReceive
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
//當搜尋結束後呼叫onReceive
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
//…
private BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)){
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// 已經配對的則跳過
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + “\n” + device.getAddress()); //儲存裝置地址與名字
}
}else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) { //搜尋結束
if (mNewDevicesArrayAdapter.getCount() == 0) {
mNewDevicesArrayAdapter.add(“沒有搜尋到裝置”);
}
}
}
};
4.建立連線
查詢到裝置 後，則需要建立本機與其他裝置之間的連線。
一般用本機搜尋其他藍芽裝置時，本機可以作為一個服務端，接收其他裝置的連線。
啟動一個伺服器端的執行緒，死迴圈等待客戶端的連線，這與ServerSocket極為相似。
這個執行緒在準備連線之前啟動
複製程式碼
//UUID可以看做一個埠號
private static final UUID MY_UUID =
UUID.fromString(“fa87c0d0-afac-11de-8a39-0800200c9a66”);
//像一個伺服器一樣時刻監聽是否有連線建立
private class AcceptThread extends Thread{
private BluetoothServerSocket serverSocket;
public AcceptThread(boolean secure){
BluetoothServerSocket temp = null;
try {
temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(
NAME_INSECURE, MY_UUID);
} catch (IOException e) {
Log.e("app", "listen() failed", e);
}
serverSocket = temp;
}
public void run(){
BluetoothSocket socket=null;
while(true){
try {
socket = serverSocket.accept();
} catch (IOException e) {
Log.e("app", "accept() failed", e);
break;
}
}
if(socket!=null){
//此時可以新建一個數據交換執行緒，把此socket傳進去
}
}
//取消監聽
public void cancel(){
try {
serverSocket.close();
} catch (IOException e) {
Log.e("app", "Socket Type" + socketType + "close() of server failed", e);
}
}
}
5.交換資料
搜尋到裝置後可以獲取裝置的地址，通過此地址獲取一個BluetoothDeviced物件，可以看做客戶端，通過此物件device.createRfcommSocketToServiceRecord(MY_UUID);同一個UUID可與伺服器建立連接獲取另一個socket物件，由此服務端與客戶端各有一個socket物件，此時
他們可以互相交換資料了。
創立客戶端socket可建立執行緒
//另一個裝置去連線本機,相當於客戶端
private class ConnectThread extends Thread{
private BluetoothSocket socket;
private BluetoothDevice device;
public ConnectThread(BluetoothDevice device,boolean secure){
this.device = device;
BluetoothSocket tmp = null;
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE);
} catch (IOException e) {
Log.e("app", "create() failed", e);
}
}
public void run(){
mBluetoothAdapter.cancelDiscovery(); //取消裝置查詢
try {
socket.connect();
} catch (IOException e) {
try {
socket.close();
} catch (IOException e1) {
Log.e("app", "unable to close() "+
" socket during connection failure", e1);
}
connetionFailed(); //連線失敗
return;
}
//此時可以新建一個數據交換執行緒，把此socket傳進去
}
public void cancel() {
try {
socket.close();
} catch (IOException e) {
Log.e("app", "close() of connect socket failed", e);
}
}
}
6.建立資料通訊執行緒，進行讀取資料
//建立連線後，進行資料通訊的執行緒
private class ConnectedThread extends Thread{
private BluetoothSocket socket;
private InputStream inStream;
private OutputStream outStream;
public ConnectedThread(BluetoothSocket socket){
this.socket = socket;
try {
//獲得輸入輸出流
inStream = socket.getInputStream();
outStream = socket.getOutputStream();
} catch (IOException e) {
Log.e("app", "temp sockets not created", e);
}
}
public void run(){
byte[] buff = new byte[1024];
int len=0;
//讀資料需不斷監聽，寫不需要
while(true){
try {
len = inStream.read(buff);
//把讀取到的資料傳送給UI進行顯示
Message msg = handler.obtainMessage(BluetoothChat.MESSAGE_READ,
len, -1, buff);
msg.sendToTarget();
} catch (IOException e) {
Log.e("app", "disconnected", e);
connectionLost(); //失去連線
start(); //重新啟動伺服器
break;
}
}
}
public void write(byte[] buffer) {
try {
outStream.write(buffer);
// Share the sent message back to the UI Activity
handler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e("app", "Exception during write", e);
}
}
public void cancel() {
try {
socket.close();
} catch (IOException e) {
Log.e("app", "close() of connect socket failed", e);
}
}
}