蓝牙

什么是蓝牙？

是一种无线技术标准，可实现固定设备、移动设备和楼宇个人域网之间的短距离数据交换，我们主要掌握这几项技能：

清单文件

打开蓝牙

        Intent intent = new Intent();
        intent.setAction(BluetoothAdapter.ACTION_REQUEST_ENABLE);//打开蓝牙
        intent.setAction(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);//允许被其他设备发现
        intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 200);//设置允许被搜索时间200s内可以被搜索到
        startActivityForResult(intent, 201);

关闭蓝牙

 bluetoothAdapter.disable();//关闭蓝牙

搜索蓝牙

bluetoothAdapter.startDiscovery();//搜索设备

显示已匹配的蓝牙

Set<BluetoothDevice> bondedDevices = bluetoothAdapter.getBondedDevices();

取消搜索

bluetoothAdapter.cancelDiscovery();//取消搜索

搜索其他蓝牙的广播

		//注册蓝牙
 		myReceiver = new MyReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(BluetoothDevice.ACTION_FOUND);//扫描到远程设备
        registerReceiver(myReceiver,intentFilter);

 class MyReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            if(intent.getAction().equals(BluetoothDevice.ACTION_FOUND)){//如果找到蓝牙的话
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if(device!=null){
                    list_blue.add(device);
                    myAdapter2.notifyDataSetChanged();
                }
            }
        }
    }

蓝牙间的相互通信

服务端

 new Thread(){
            @Override
            public void run() {
                super.run();
                try {
                    BluetoothServerSocket serverSocket = bluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord(bluetoothAdapter.getName(), uuid);
                    while(true){
                        BluetoothSocket socket = serverSocket.accept();
                        new ServiceThread(handler,socket).start();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }.start();

/////////////////////////////////////////////////////////
public class ServiceThread extends Thread {
    Handler handler;
    BluetoothSocket socket;

    public ServiceThread(Handler handler, BluetoothSocket socket) {
        this.handler = handler;
        this.socket = socket;
    }

    @Override
    public void run() {
        super.run();
        try {
            InputStream is = socket.getInputStream();
            byte[] buffer = new byte[1024];
            int len = 0;
            StringBuffer sb = new StringBuffer();
            while ((len = is.read(buffer)) != -1) {
                sb.append(new String(buffer, 0, len));
                Message obtain = Message.obtain();
                obtain.what = 101;
                obtain.obj = buffer;
                handler.sendMessage(obtain);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

服务端

BluetoothDevice device = list.get(position);
        try {
            //创建socket
            BluetoothSocket socket = device.createInsecureRfcommSocketToServiceRecord(uuid);
            //connect 连接
            socket.connect();
            //发送数据
            socket.getOutputStream().write("OPPO A3来了！".getBytes());
            Toast.makeText(this, "发送成功！", Toast.LENGTH_SHORT).show();

        } catch (IOException e) {
            e.printStackTrace();
        }

涉及到的类

BluetoothManager 蓝牙管理类，管理BluetoothAdapter。主要负责管理蓝牙的本地连接。
BluetoothAdapter 蓝牙适配器类：代表本蓝牙设备
BluetoothDevice 蓝牙设备，配对后的远程蓝牙设备.
BluetoothServiceSocket 服务端连接类
BluetoothSocket：客户端连接类
UUID（universal unique identifier ， 全局唯一标识符）
格式如下：UUID格式一般是”xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”，可到http://www.uuidgenerator.com 申请。UUID分为5段，是一个8-4-4-4-12的字符串，这个字符串要求永不重复。蓝牙建立连接时双方必须使用固定的UUID
例如：文件传输服务
OBEXFileTransferServiceClass_UUID = ‘{00001106-0000-1000-8000-00805F9B34FB}’

工作原理