AS（六）实现蓝牙通信

类微信实现Bluetooth聊天
需求要求：两个连接的手机选择后可进行蓝牙聊天

以下为部分核心代码展示
要想实现蓝牙聊天，首先需要获得蓝牙权限，在项目的配置文件AndroidManifest.xml加入下面两条代码

 <uses-permission android:name="android.permission.BLUETOOTH"/>
 <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

检查该设备是否支持蓝牙连接

 private void isSupportBluetooth() {
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
 
        if (bluetoothAdapter == null
                || !getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)) {
            showNotSupportBluetoothDialog();
            Log.e(TAG, "not support bluetooth");
        } else {
            Log.e(TAG, " support bluetooth");
        }
    }

主动发起连接的线程ConnectThread

        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
            mmDevice=device;
            BluetoothSocket tmp = null;
            // Get a BluetoothSocket to connect with the given BluetoothDevice
            try{
                // 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
            mAdapter.cancelDiscovery();
            try{
                // Connect the device through the socket. This will block
                // until it succeeds or throws an exception
                mmSocket.connect();
            }catch (IOException e){
                connectionFailed();
                // Unable to connect; close the socket and get out
                try{
                    mmSocket.close();
                }catch (IOException e2){}
 
                //ChatService.this.start();
               return;
           }
            synchronized(ChatService.this){
                mConnectedThread = null;
           }
            connected(mmSocket,mmDevice);
        }
 
        public void cancel(){
           /* try{
                mmSocket.close();
            }catch (IOException e){}*/
        }
    }

蓝牙配对成功后，通过BluetoothDevice的createRfcommSocketToServiceRecord()方法和蓝牙设备连接，返回BluetoothSocket对象，进而获得输入输出流，进行数据交互。

mSocket = device.createRfcommSocketToServiceRecord(UUID.fromString(uuid));
 
 mSocket.connect();
 
 mOutputStream = mSocket.getOutputStream();
 
mInputStream = mSocket.getInputStream();
复制代码

构造函数中设置输入输出流， run()方法中使用阻塞模式的 InputStream.read()循环读取输入流，然后发送到 UI 线程中更新聊天消息，本线程也提供了 write() 将聊天消息写入输出流传输至对方，传输成功后回写入 UI 线程。最后使用cancel()关闭连接的 socket

 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;
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }
            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        @Override
        public void run() {
            byte[] buffer = new byte[1024];
            int bytes;
            while (true) {
                try {
                    bytes = mmInStream.read(buffer);
                    mHandler.obtainMessage(weixinFragment.MESSAGE_READ, bytes, -1, buffer).sendToTarget();
                } catch (IOException e) {
                    connectionLost();
                    break;
                }
            }
        }

        public void write(byte[] buffer) {
            try {
                mmOutStream.write(buffer);
                mHandler.obtainMessage(weixinFragment.MESSAGE_WRITE, -1, -1, buffer).sendToTarget();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

源码地址：https://gitee.com/zhangjianhui1010/lanyatongxin