每日速讯：什么是蓝牙Android平台？如何设置蓝牙？

什么是蓝牙

Android 平台包含蓝牙网络堆栈支持，此支持能让设备以无线方式与其他蓝牙设备交换数据。应用框架提供通过 Android Bluetooth API 访问蓝牙功能的权限。这些 API 允许应用以无线方式连接到其他蓝牙设备，从而实现点到点和多点无线功能。

【资料图】

Android 应用可通过 Bluetooth API 执行以下操作：

扫描其他蓝牙设备查询本地蓝牙适配器的配对蓝牙设备建立 RFCOMM 通道通过服务发现连接到其他设备与其他设备进行双向数据传输管理多个连接

蓝牙权限

如要在应用中使用蓝牙功能，必须声明两个权限。第一个是 BLUETOOTH。第二个是 ACCESS_FINE_LOCATION。

设置蓝牙

1.获取

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();if (bluetoothAdapter == null) {// Device doesn"t support Bluetooth}

2.启用

if (!bluetoothAdapter.isEnabled()) {Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);}

查找设备

1.查询已配对的设备

SetpairedDevices = bluetoothAdapter.getBondedDevices();if (pairedDevices.size() > 0) {// There are paired devices. Get the name and address of each paired device.    for (BluetoothDevice device : pairedDevices) {String deviceName = device.getName();        String deviceHardwareAddress = device.getAddress(); // MAC address    }}

2.发现设备

@Overrideprotected void onCreate(Bundle savedInstanceState) {...    // Register for broadcasts when a device is discovered.    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);    registerReceiver(receiver, filter);}// Create a BroadcastReceiver for ACTION_FOUND.private final BroadcastReceiver receiver = new BroadcastReceiver() {public void onReceive(Context context, Intent intent) {String action = intent.getAction();        if (BluetoothDevice.ACTION_FOUND.equals(action)) {// Discovery has found a device. Get the BluetoothDevice            // object and its info from the Intent.            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);            String deviceName = device.getName();            String deviceHardwareAddress = device.getAddress(); // MAC address        }    }};@Overrideprotected void onDestroy() {super.onDestroy();    ...    // Don"t forget to unregister the ACTION_FOUND receiver.    unregisterReceiver(receiver);}

连接设备

private class AcceptThread extends Thread {private final BluetoothServerSocket mmServerSocket;    public AcceptThread() {// Use a temporary object that is later assigned to mmServerSocket        // because mmServerSocket is final.        BluetoothServerSocket tmp = null;        try {// MY_UUID is the app"s UUID string, also used by the client code.            tmp = bluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);        } catch (IOException e) {Log.e(TAG, "Socket"s listen() method failed", e);        }        mmServerSocket = tmp;    }    public void run() {BluetoothSocket socket = null;        // Keep listening until exception occurs or a socket is returned.        while (true) {try {socket = mmServerSocket.accept();            } catch (IOException e) {Log.e(TAG, "Socket"s accept() method failed", e);                break;            }            if (socket != null) {// A connection was accepted. Perform work associated with                // the connection in a separate thread.                manageMyConnectedSocket(socket);                mmServerSocket.close();                break;            }        }    }    // Closes the connect socket and causes the thread to finish.    public void cancel() {try {mmServerSocket.close();        } catch (IOException e) {Log.e(TAG, "Could not close the connect socket", e);        }    }}

服务端代码

class AcceptThread extends Thread {private BluetoothServerSocket mServerSocket;        private BluetoothSocket mSocket;        private InputStream btIs;        private OutputStream btOs;        private PrintWriter writer;        private boolean canAccept;        private boolean canRecv;         public AcceptThread() {canAccept = true;            canRecv = true;        }         @Override        public void run() {try {//获取套接字                BluetoothServerSocket temp = mBluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord("TEST", UUID.fromString(BT_UUID));                mServerSocket = temp;                //监听连接请求 -- 作为测试，只允许连接一个设备                if (mServerSocket != null) {// while (canAccept) {mSocket = mServerSocket.accept();//阻塞等待客户端连接                    sendHandlerMsg("有客户端连接");                    // }                }                //获取输入输出流                btIs = mSocket.getInputStream();                btOs = mSocket.getOutputStream();                //通讯-接收消息                BufferedReader reader = new BufferedReader(new InputStreamReader(btIs, "UTF-8"));                String content = null;                while (canRecv) {content = reader.readLine();                    sendHandlerMsg("收到消息：" + content);                }            } catch (IOException e) {e.printStackTrace();            } finally {try {if (mSocket != null) {mSocket.close();                    }                    // btIs.close();//两个输出流都依赖socket，关闭socket即可                    // btOs.close();                } catch (IOException e) {e.printStackTrace();                    sendHandlerMsg("错误：" + e.getMessage());                }            }        }         private void sendHandlerMsg(String content) {Message msg = mHandler.obtainMessage();            msg.what = 1001;            msg.obj = content;            mHandler.sendMessage(msg);        }         public void write(String msg) {if (btOs != null) {try {if (writer == null) {writer = new PrintWriter(new OutputStreamWriter(btOs, "UTF-8"), true);                    }                    writer.println(msg);                } catch (UnsupportedEncodingException e) {e.printStackTrace();                    writer.close();                    sendHandlerMsg("错误：" + e.getMessage());                }            }        }    }

客户端代码

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 final.        BluetoothSocket tmp = null;        mmDevice = device;        try {// Get a BluetoothSocket to connect with the given BluetoothDevice.            // MY_UUID is the app"s UUID string, also used in the server code.            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);        } catch (IOException e) {Log.e(TAG, "Socket"s create() method failed", e);        }        mmSocket = tmp;    }    public void run() {// Cancel discovery because it otherwise slows down the connection.        bluetoothAdapter.cancelDiscovery();        try {// Connect to the remote device through the socket. This call blocks            // until it succeeds or throws an exception.            mmSocket.connect();        } catch (IOException connectException) {// Unable to connect; close the socket and return.            try {mmSocket.close();            } catch (IOException closeException) {Log.e(TAG, "Could not close the client socket", closeException);            }            return;        }        // The connection attempt succeeded. Perform work associated with        // the connection in a separate thread.        manageMyConnectedSocket(mmSocket);    }    // Closes the client socket and causes the thread to finish.    public void cancel() {try {mmSocket.close();        } catch (IOException e) {Log.e(TAG, "Could not close the client socket", e);        }    }}

运行截图