实现Bluetooth聊天

1. 清单文件注册权限

<!--下面2个是普通权限，只需要在清单文件里注册，不需要在程序里动态申请-->
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />

2. 布局 device_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent"><TextView android:id="@+id/title_paired_devices"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="@string/title_paired_devices"android:visibility="gone"android:background="#666"android:textColor="#fff"android:paddingLeft="5dp" /><ListView android:id="@+id/paired_devices"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_weight="1" /><TextView android:id="@+id/title_new_devices"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="@string/title_other_devices"android:visibility="gone"android:background="#666"android:textColor="#fff"android:paddingLeft="5dp" /><!--android:visibility="gone"表示不占空间的隐藏，invisible是占空间--><ListView android:id="@+id/new_devices"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_weight="2" /><Button android:id="@+id/button_scan"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="@string/button_scan" />
</LinearLayout>

3.string.xml

<resources><string name="app_name">MyWechat</string><!-- TODO: Remove or change this placeholder text --><string name="hello_blank_fragment">Hello blank fragment</string><string name="send">发送</string><string name="not_connected">你没有链接一个设备</string><string name="bt_not_enabled_leaving">蓝牙不可用，离开聊天室</string><string name="title_connecting">链接中...</string><string name="title_connected_to">连接到：</string><string name="title_not_connected">无链接</string><string name="scanning">蓝牙设备搜索中...</string><string name="select_device">选择一个好友链接</string><string name="none_paired">没有配对好友</string><string name="none_found">附近没有发现好友</string><string name="title_paired_devices">已配对好友</string><string name="title_other_devices">其它可连接好友</string><string name="button_scan">搜索好友</string><string name="connect">我的好友</string><string name="discoverable">设置在线</string><string name="back">退出</string><string name="startVideo">开始聊天</string><string name="stopVideo">结束聊天</string>
</resources>

4.在tab01聊天区域添加控件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent"><!--新版Android支持的Toolbar，对标题栏布局--><android.support.v7.widget.Toolbarandroid:id="@+id/toolbar"android:layout_width="match_parent"android:layout_height="wrap_content"><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="horizontal"><TextViewandroid:id="@+id/title_left_text"style="?android:attr/windowTitleStyle"android:layout_width="0dp"android:layout_height="match_parent"android:layout_alignParentLeft="true"android:layout_weight="1"android:gravity="left"android:ellipsize="end"android:singleLine="true" /><TextViewandroid:id="@+id/title_right_text"android:layout_width="0dp"android:layout_height="match_parent"android:layout_alignParentRight="true"android:layout_weight="1"android:ellipsize="end"android:gravity="right"android:singleLine="true"android:textColor="#fff" /></LinearLayout></android.support.v7.widget.Toolbar><ListView android:id="@+id/in"android:layout_width="match_parent"android:layout_height="match_parent"android:stackFromBottom="true"android:transcriptMode="alwaysScroll"android:layout_weight="1" /><LinearLayoutandroid:orientation="horizontal"android:layout_width="match_parent"android:layout_height="wrap_content" ><EditText android:id="@+id/edit_text_out"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_weight="1"android:layout_gravity="bottom" /><Button android:id="@+id/button_send"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/send"/></LinearLayout>
</LinearLayout>

5.编写用于蓝牙会话的服务组件ChatService，其文件代码如下：

public class ChatService {//本应用的主Activity组件名称private static final String NAME = "MainActivity";// UUID：通用唯一识别码,是一个128位长的数字，一般用十六进制表示//算法的核心思想是结合机器的网卡、当地时间、一个随机数来生成//在创建蓝牙连接private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");private final BluetoothAdapter mAdapter;private final Handler mHandler;private AcceptThread mAcceptThread;private ConnectThread mConnectThread;private ConnectedThread mConnectedThread;private int mState;public static final int STATE_NONE = 0;public static final int STATE_LISTEN = 1;public static final int STATE_CONNECTING = 2;public static final int STATE_CONNECTED = 3;//构造方法，接收UI主线程传递的对象public ChatService(Context context, Handler handler) {//构造方法完成蓝牙对象的创建mAdapter = BluetoothAdapter.getDefaultAdapter();mState = STATE_NONE;mHandler = handler;}private synchronized void setState(int state) {mState = state;mHandler.obtainMessage(weixinFragment.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();}public synchronized int getState() {return mState;}public synchronized void start() {if (mConnectThread != null) {mConnectThread.cancel();mConnectThread = null;}if (mConnectedThread != null) {mConnectedThread.cancel();mConnectedThread = null;}if (mAcceptThread == null) {mAcceptThread = new AcceptThread();mAcceptThread.start();}setState(STATE_LISTEN);}//取消 CONNECTING 和 CONNECTED 状态下的相关线程，然后运行新的 mConnectThread 线程public synchronized void connect(BluetoothDevice device) {if (mState == STATE_CONNECTING) {if (mConnectThread != null) {mConnectThread.cancel();mConnectThread = null;}}if (mConnectedThread != null) {mConnectedThread.cancel();mConnectedThread = null;}mConnectThread = new ConnectThread(device);mConnectThread.start();setState(STATE_CONNECTING);}/*开启一个 ConnectedThread 来管理对应的当前连接。之前先取消任意现存的 mConnectThread 、mConnectedThread 、 mAcceptThread 线程，然后开启新 mConnectedThread ，传入当前刚刚接受的socket 连接。最后通过 Handler来通知UI连接*/public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {if (mConnectThread != null) {mConnectThread.cancel();mConnectThread = null;}if (mConnectedThread != null) {mConnectedThread.cancel();mConnectedThread = null;}if (mAcceptThread != null) {mAcceptThread.cancel();mAcceptThread = null;}mConnectedThread = new ConnectedThread(socket);mConnectedThread.start();Message msg = mHandler.obtainMessage(weixinFragment.MESSAGE_DEVICE_NAME);Bundle bundle = new Bundle();bundle.putString(weixinFragment.DEVICE_NAME, device.getName());msg.setData(bundle);mHandler.sendMessage(msg);setState(STATE_CONNECTED);}// 停止所有相关线程，设当前状态为 NONEpublic synchronized void stop() {if (mConnectThread != null) {mConnectThread.cancel();mConnectThread = null;}if (mConnectedThread != null) {mConnectedThread.cancel();mConnectedThread = null;}if (mAcceptThread != null) {mAcceptThread.cancel();mAcceptThread = null;}setState(STATE_NONE);}// 在 STATE_CONNECTED 状态下，调用 mConnectedThread 里的 write 方法，写入 bytepublic void write(byte[] out) {ConnectedThread r;synchronized (this) {if (mState != STATE_CONNECTED)return;r = mConnectedThread;}r.write(out);}// 连接失败的时候处理，通知 ui ，并设为 STATE_LISTEN 状态private void connectionFailed() {setState(STATE_LISTEN);Message msg = mHandler.obtainMessage(weixinFragment.MESSAGE_TOAST);Bundle bundle = new Bundle();bundle.putString(weixinFragment.TOAST, "链接不到设备");msg.setData(bundle);mHandler.sendMessage(msg);}// 当连接失去的时候，设为 STATE_LISTEN 状态并通知 uiprivate void connectionLost() {setState(STATE_LISTEN);Message msg = mHandler.obtainMessage(weixinFragment.MESSAGE_TOAST);Bundle bundle = new Bundle();bundle.putString(weixinFragment.TOAST, "设备链接中断");msg.setData(bundle);mHandler.sendMessage(msg);}// 创建监听线程，准备接受新连接。使用阻塞方式，调用 BluetoothServerSocket.accept()private class AcceptThread extends Thread {private final BluetoothServerSocket mmServerSocket;public AcceptThread() {BluetoothServerSocket tmp = null;try {//使用射频端口（RF comm）监听tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);} catch (IOException e) {}mmServerSocket = tmp;}@Overridepublic void run() {setName("AcceptThread");BluetoothSocket socket = null;while (mState != STATE_CONNECTED) {try {socket = mmServerSocket.accept();} catch (IOException e) {break;}if (socket != null) {synchronized (ChatService.this) {switch (mState) {case STATE_LISTEN:case STATE_CONNECTING:connected(socket, socket.getRemoteDevice());break;case STATE_NONE:case STATE_CONNECTED:try {socket.close();} catch (IOException e) {e.printStackTrace();}break;}}}}}public void cancel() {try {mmServerSocket.close();} catch (IOException e) {e.printStackTrace();}}}/*连接线程，专门用来对外发出连接对方蓝牙的请求和处理流程。构造函数里通过 BluetoothDevice.createRfcommSocketToServiceRecord() ，从待连接的 device 产生 BluetoothSocket. 然后在 run 方法中 connect ，成功后调用 BluetoothChatSevice 的 connected() 方法。定义 cancel() 在关闭线程时能够关闭相关socket 。*/private class ConnectThread extends Thread {private final BluetoothSocket mmSocket;private final BluetoothDevice mmDevice;public ConnectThread(BluetoothDevice device) {mmDevice = device;BluetoothSocket tmp = null;try {tmp = device.createRfcommSocketToServiceRecord(MY_UUID);} catch (IOException e) {e.printStackTrace();}mmSocket = tmp;}@Overridepublic void run() {setName("ConnectThread");mAdapter.cancelDiscovery();try {mmSocket.connect();} catch (IOException e) {connectionFailed();try {mmSocket.close();} catch (IOException e2) {e.printStackTrace();}ChatService.this.start();return;}synchronized (ChatService.this) {mConnectThread = null;}connected(mmSocket, mmDevice);}public void cancel() {try {mmSocket.close();} catch (IOException e) {e.printStackTrace();}}}/*双方蓝牙连接后一直运行的线程；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;}@Overridepublic 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();}}}}

6.新建Activity组件DeviceList，实现选取与之会话的蓝牙设备

public class DeviceList extends AppCompatActivity {private BluetoothAdapter mBtAdapter;private ArrayAdapter<String> mPairedDevicesArrayAdapter;private ArrayAdapter<String> mNewDevicesArrayAdapter;public static String EXTRA_DEVICE_ADDRESS = "device_address";  //Mac地址//定义广播接收者，用于处理扫描蓝牙设备后的结果private final BroadcastReceiver mReceiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {String action = intent.getAction();if (BluetoothDevice.ACTION_FOUND.equals(action)) {BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);if (device.getBondState() != BluetoothDevice.BOND_BONDED) {mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());}} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {if (mNewDevicesArrayAdapter.getCount() == 0) {String noDevices = getResources().getText(R.string.none_found).toString();mNewDevicesArrayAdapter.add(noDevices);}}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.device_list);//在被调用活动里，设置返回结果码setResult(Activity.RESULT_CANCELED);init();  //活动界面}private void init() {Button scanButton = findViewById(R.id.button_scan);scanButton.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {Toast.makeText(DeviceList.this, R.string.scanning, Toast.LENGTH_LONG).show();doDiscovery();  //搜索蓝牙设备}});
//        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
//        mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);//已配对蓝牙设备列表ListView pairedListView =findViewById(R.id.paired_devices);pairedListView.setAdapter(mPairedDevicesArrayAdapter);pairedListView.setOnItemClickListener(mPaireDeviceClickListener);//未配对蓝牙设备列表ListView newDevicesListView = findViewById(R.id.new_devices);newDevicesListView.setAdapter(mNewDevicesArrayAdapter);newDevicesListView.setOnItemClickListener(mNewDeviceClickListener);//动态注册广播接收者IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);registerReceiver(mReceiver, filter);filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);registerReceiver(mReceiver, filter);mBtAdapter = BluetoothAdapter.getDefaultAdapter();Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();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);}}@Overrideprotected void onDestroy() {super.onDestroy();if (mBtAdapter != null) {mBtAdapter.cancelDiscovery();}this.unregisterReceiver(mReceiver);}private void doDiscovery() {findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);if (mBtAdapter.isDiscovering()) {mBtAdapter.cancelDiscovery();}mBtAdapter.startDiscovery();  //开始搜索蓝牙设备并产生广播//startDiscovery是一个异步方法//找到一个设备时就发送一个BluetoothDevice.ACTION_FOUND的广播}private AdapterView.OnItemClickListener mPaireDeviceClickListener = new AdapterView.OnItemClickListener() {public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {mBtAdapter.cancelDiscovery();String info = ((TextView) v).getText().toString();String address = info.substring(info.length() - 17);Intent intent = new Intent();intent.putExtra(EXTRA_DEVICE_ADDRESS, address);  //Mac地址setResult(Activity.RESULT_OK, intent);finish();}};private AdapterView.OnItemClickListener mNewDeviceClickListener = new AdapterView.OnItemClickListener() {public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {mBtAdapter.cancelDiscovery();Toast.makeText(DeviceList.this, "请在蓝牙设置界面手动连接设备",Toast.LENGTH_SHORT).show();Intent intent = new Intent(Settings.ACTION_BLUETOOTH_SETTINGS);startActivityForResult(intent,1);}};//回调方法：进入蓝牙配对设置界面返回后执行@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);init();  //刷新好友列表}
}

源代码地址：https://gitee.com/dai_wen/bluetooth