2013.09.05——— android 蓝牙聊天室之官方例子
蓝牙开发的大致流程：
1、蓝牙权限
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> <uses-permission android:name="android.permission.BLUETOOTH" />
2、认设备是否支持蓝牙
/** * 确认设备是否支持蓝牙 * 如果getDefaultAdapter()返回null,则这个设备不支持蓝牙 */ mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); // If the adapter is null, then Bluetooth is not supported //手机不支持蓝牙 if (mBluetoothAdapter == null) { Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show(); finish(); return; }3、确定蓝牙能够使用
/** * 确定蓝牙能够使用。 * 通过isEnabled()来检查蓝牙当前是否可用。 * 如果这个方法返回false,则蓝牙不能够使用。这个时候 就请求蓝牙使用，通过intent来请求 * 在onActivityResult（）里面判断 */ if (!mBluetoothAdapter.isEnabled()) { Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableIntent, REQUEST_ENABLE_BT); // Otherwise, setup the chat session }会打开一个对话框中显示请求使用蓝牙权限。如果响应"Yes",这个进程完成（或失败）后你的应用将能够使用蓝牙，选择no，就结束应用
case REQUEST_ENABLE_BT: // When the request to enable Bluetooth returns if (resultCode == Activity.RESULT_OK) { // Bluetooth is now enabled, so set up a chat session //请求蓝牙成功，这个时候 蓝也可用 setupChat(); } else { // User did not enable Bluetooth or an error occurred //请求蓝牙失败，退出应用 Log.d(TAG, "BT not enabled"); Toast.makeText(this, R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show(); finish(); }4、最为服务器端，你必须让其他设备能够看到你，才能跟你建立连接
//设置自己可以被其他设备搜索到 private void ensureDiscoverable() { if(D) Log.d(TAG, "ensure discoverable"); 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); } }5、找已经匹配的设备
在搜索设备前，查询配对设备看需要的设备是否已经是已经存在是很值得的，可以调用getBondedDevices()来做到，该函数会返回一个描述配对设备BluetoothDevice的结果集
//查找已经匹配的设备 Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices(); // If there are paired devices, add each one to the ArrayAdapter if (pairedDevices.size() > 0) { findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE); for (BluetoothDevice device : pairedDevices) { mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); } } else { String noDevices = getResources().getText(R.string.none_paired).toString(); mPairedDevicesArrayAdapter.add(noDevices); }6、扫描设备
/** * Start device discover with the BluetoothAdapter */ private void doDiscovery() { if (D) Log.d(TAG, "doDiscovery()"); // Indicate scanning in the title setProgressBarIndeterminateVisibility(true); setTitle(R.string.scanning); // Turn on sub-title for new devices findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE); // If we're already discovering, stop it //如果正在搜索 就先停止 if (mBtAdapter.isDiscovering()) { mBtAdapter.cancelDiscovery(); } // Request discover from BluetoothAdapter //搜索设备 用BroadcastReceiver接受BluetoothDevice.ACTION_FOUND mBtAdapter.startDiscovery(); }要开始搜索设备，只需简单的调用startDiscovery() 。该函数时异步的，调用后立即返回，返回值表示搜索是否成功开始。可以再BroadcastReceiver里面监听结果
private final BroadcastReceiver mReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); // When discovery finds a device if (BluetoothDevice.ACTION_FOUND.equals(action)) { // Get the BluetoothDevice object from the Intent BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); // If it's already paired, skip it, because it's been listed already if (device.getBondState() != BluetoothDevice.BOND_BONDED) { mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress()); } // When discovery is finished, change the Activity title } };7、作为客户端连接
扫描出来的列表，单击任意一个item，得到这个设备的mac地址和name
// The on-click listener for all devices in the ListViews private OnItemClickListener mDeviceClickListener = new OnItemClickListener() { public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) { // Cancel discovery because it's costly and we're about to connect //停止搜索 mBtAdapter.cancelDiscovery(); // Get the device MAC address, which is the last 17 chars in the View String info = ((TextView) v).getText().toString(); String address = info.substring(info.length() - 17); // Create the result Intent and include the MAC address Intent intent = new Intent(); intent.putExtra(EXTRA_DEVICE_ADDRESS, address); // Set result and finish this Activity setResult(Activity.RESULT_OK, intent); finish(); } };根据mac地址 得到远端BluetoothDevice
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
然后 根据device得到BluetoothSocket,并建立连接
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"; // Get a BluetoothSocket for a connection with the // given BluetoothDevice //来生成一个BluetoothSocket对象 //这个uuid必须服务器和客户端是同一个 try { if (secure) { tmp = device.createRfcommSocketToServiceRecord( MY_UUID_SECURE); } else { tmp = device.createInsecureRfcommSocketToServiceRecord( MY_UUID_INSECURE); } } catch (IOException e) { Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e); } mmSocket = tmp; } public void run() { Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType); //设置当前线程名字 setName("ConnectThread" + mSocketType); // Always cancel discovery because it will slow down a connection //因为扫描设备 很浪费资源 停止扫描 mAdapter.cancelDiscovery(); // Make a connection to the BluetoothSocket //用connect()完成连接 //系统会在远程设备上完成一个SDP查找来匹配UUID。 //如果查找成功并且远程设备接受连接，就共享RFCOMM信道，connect()会返回。 //这也是一个阻塞的调用，不管连接失败还是超时（12秒）都会抛出异常。 try { // This is a blocking call and will only return on a // successful connection or an exception mmSocket.connect(); } catch (IOException e) { // Close the socket try { mmSocket.close(); } catch (IOException e2) { Log.e(TAG, "unable to close() " + mSocketType + " socket during connection failure", e2); } connectionFailed(); return; } // Reset the ConnectThread because we're done synchronized (BluetoothChatService.this) { mConnectThread = null; } // Start the connected thread //启动连接成功 可以通信的线程 connected(mmSocket, mmDevice, mSocketType); } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e); } } }8、作为服务器端建立连接
private class AcceptThread extends Thread { // The local server socket private final BluetoothServerSocket mmServerSocket; private String mSocketType; public AcceptThread(boolean secure) { BluetoothServerSocket tmp = null; mSocketType = secure ? "Secure":"Insecure"; // Create a new listening server socket //通过调用listenUsingRfcommWithServiceRecord(String, UUID)得到一个BluetoothServerSocket对象 try { if (secure) { tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID_SECURE); } else { tmp = mAdapter.listenUsingInsecureRfcommWithServiceRecord( NAME_INSECURE, MY_UUID_INSECURE); } } catch (IOException e) { Log.e(TAG, "Socket Type: " + mSocketType + "listen() failed", e); } mmServerSocket = tmp; } public void run() { if (D) Log.d(TAG, "Socket Type: " + mSocketType + "BEGIN mAcceptThread" + this); setName("AcceptThread" + mSocketType); BluetoothSocket socket = null; // Listen to the server socket if we're not connected while (mState != STATE_CONNECTED) { try { // This is a blocking call and will only return on a // successful connection or an exception //通过调用accept()来侦听连接请求。 socket = mmServerSocket.accept(); } catch (IOException e) { Log.e(TAG, "Socket Type: " + mSocketType + "accept() failed", e); break; } // If a connection was accepted if (socket != null) { synchronized (BluetoothChatService.this) { switch (mState) { case STATE_LISTEN: case STATE_CONNECTING: // Situation normal. Start the connected thread. connected(socket, socket.getRemoteDevice(), mSocketType); break; case STATE_NONE: case STATE_CONNECTED: // Either not ready or already connected. Terminate new socket. try { socket.close(); } catch (IOException e) { Log.e(TAG, "Could not close unwanted socket", e); } break; } } } } if (D) Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType); } public void cancel() { if (D) 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); } } }9、与远端设备通信
//处理与远端的通信 private class ConnectedThread extends Thread { private final BluetoothSocket mmSocket; private final InputStream mmInStream; private final OutputStream mmOutStream; public ConnectedThread(BluetoothSocket socket, String socketType) { Log.d(TAG, "create ConnectedThread: " + socketType); mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; // Get the BluetoothSocket input and output streams try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { Log.e(TAG, "temp sockets not created", e); } mmInStream = tmpIn; mmOutStream = tmpOut; } public void run() { Log.i(TAG, "BEGIN mConnectedThread"); byte[] buffer = new byte[1024]; int bytes; // Keep listening to the InputStream while connected while (true) { try { // Read from the InputStream bytes = mmInStream.read(buffer); // Send the obtained bytes to the UI Activity mHandler.obtainMessage(BluetoothChat.MESSAGE_READ, bytes, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "disconnected", e); connectionLost(); // Start the service over to restart listening mode BluetoothChatService.this.start(); break; } } } /** * Write to the connected OutStream. * @param buffer The bytes to write */ //发送信息给远端 public void write(byte[] buffer) { try { mmOutStream.write(buffer); // Share the sent message back to the UI Activity mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "Exception during write", e); } } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); } } }附件是官网的例子，稍微加了点注释
