- 使用蓝牙的响应权限
- 配置本机蓝牙模块
在这里首先要了解对蓝牙操作一个核心类BluetoothAdapter
BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter(); //直接打开系统的蓝牙设置面板Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(intent, 0x1); //直接打开蓝牙adapter.enable(); //关闭蓝牙adapter.disable(); //打开本机的蓝牙发现功能（默认打开120秒，可以将时间最多延长至300秒）Intent discoveryIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); //设置持续时间（最多300秒）
【[Android实例] android 蓝牙开发浅析】3.搜索蓝牙设备
使用BluetoothAdapter的startDiscovery()方法来搜索蓝牙设备
startDiscovery()方法是一个异步方法，调用后会立即返回。该方法会进行对其他蓝牙设备的搜索，该过程会持续12秒。该方法调用后，搜索过程实际上是在一个System Service中进行的，所以可以调用cancelDiscovery()方法来停止搜索（该方法可以在未执行discovery请求时调用）。
请求Discovery后，系统开始搜索蓝牙设备，在这个过程中，系统会发送以下三个广播：
ACTION_DISCOVERY_START：开始搜索
ACTION_DISCOVERY_FINISHED：搜索结束
ACTION_FOUND：找到设备，这个Intent中包含两个extra fields：EXTRA_DEVICE和EXTRA_CLASS，分别包含BluetooDevice和BluetoothClass。
我们可以自己注册相应的BroadcastReceiver来接收响应的广播，以便实现某些功能
// 创建一个接收ACTION_FOUND广播的BroadcastReceiverprivate final BroadcastReceiver mReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) {String action = intent.getAction(); // 发现设备if (BluetoothDevice.ACTION_FOUND.equals(action)) {// 从Intent中获取设备对象BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // 将设备名称和地址放入array adapter，以便在ListView中显示mArrayAdapter.add(device.getName() + "\n" + device.getAddress()); } } }; // 注册BroadcastReceiverIntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); registerReceiver(mReceiver, filter); // 不要忘了之后解除绑定
- 蓝牙Socket通信
如果打算建议两个蓝牙设备之间的连接，则必须实现服务器端与客户端的机制。当两个设备在同一个RFCOMM channel下分别拥有一个连接的BluetoothSocket，这两个设备才可以说是建立了连接。
服务器设备与客户端设备获取BluetoothSocket的途径是不同的。服务器设备是通过accepted一个incoming connection来获取的，而客户端设备则是通过打开一个到服务器的RFCOMM channel来获取的。
通过调用BluetoothAdapter的listenUsingRfcommWithServiceRecord(String, UUID)方法来获取BluetoothServerSocket（UUID用于客户端与服务器端之间的配对）
调用BluetoothServerSocket的accept()方法监听连接请求，如果收到请求，则返回一个BluetoothSocket实例（此方法为block方法，应置于新线程中）
如果不想在accept其他的连接，则调用BluetoothServerSocket的close()方法释放资源（调用该方法后，之前获得的BluetoothSocket实例并没有close。但由于RFCOMM一个时刻只允许在一条channel中有一个连接，则一般在accept一个连接后，便close掉BluetoothServerSocket）
private class AcceptThread extends Thread {private final BluetoothServerSocket mmServerSocket;
public AcceptThread() {// Use a temporary object that is later assigned to mmServerSocket,// because mmServerSocket is finalBluetoothServerSocket tmp = null;
try {// MY_UUID is the app's UUID string, also used by the client code
tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
} catch (IOException e) { }
mmServerSocket = tmp;
}public void run() {
BluetoothSocket socket = null;
// Keep listening until exception occurs or a socket is returnedwhile (true) {
try {
socket = mmServerSocket.accept();
} catch (IOException e) {
break;
}// If a connection was accepted
if (socket != null) {
// Do work to manage the connection (in a separate thread)
manageConnectedSocket(socket);
mmServerSocket.close();
break;
}
}
}/** Will cancel the listening socket, and cause the thread to finish */
public void cancel() {
try {
mmServerSocket.close();
} catch (IOException e) { }
}
}客户端的实现
通过搜索得到服务器端的BluetoothService
调用BluetoothService的listenUsingRfcommWithServiceRecord(String, UUID)方法获取BluetoothSocket（该UUID应该同于服务器端的UUID）
调用BluetoothSocket的connect()方法（该方法为block方法），如果UUID同服务器端的UUID匹配，并且连接被服务器端accept，则connect()方法返回
注意：在调用connect()方法之前，应当确定当前没有搜索设备，否则连接会变得非常慢并且容易失败
private class ConnectThread extends Thread {private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {// Use a temporary object that is later assigned to mmSocket,// because mmSocket is finalBluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevicetry {// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
mmSocket = tmp;
}public void run() {
// Cancel discovery because it will slow down the connection
mBluetoothAdapter.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {// Unable to connect;
close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}// Do work to manage the connection (in a separate thread)
manageConnectedSocket(mmSocket);
}/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
} 4.连接管理（数据通信）
分别通过BluetoothSocket的getInputStream()和getOutputStream()方法获取InputStream和OutputStream
使用read(bytes[])和write(bytes[])方法分别进行读写操作
注意：read(bytes[])方法会一直block，知道从流中读取到信息，而write(bytes[])方法并不是经常的block（比如在另一设备没有及时read或者中间缓冲区已满的情况下，write方法会block）
private class ConnectedThread extends Thread {private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because// member streams are finaltry {tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }mmInStream = tmpIn;
mmOutStream = tmpOut;
}public void run() {byte[] buffer = new byte[1024];
// buffer store for the streamint bytes;
// bytes returned from read()// Keep listening to the InputStream until an exception occurswhile (true) {try {// Read from the InputStreambytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI ActivitymHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();
} catch (IOException e) {break;
}}}/* Call this from the main Activity to send data to the remote device */public void write(byte[] bytes) {try {mmOutStream.write(bytes);
} catch (IOException e) { }}/* Call this from the main Activity to shutdown the connection */public void cancel() {try {mmSocket.close();
} catch (IOException e) { }}}
