Android实现蓝牙聊天功能

Z时代
2024-01-10
分类：IT

蓝牙，时下最流行的智能设备传输数据的方式之一，通过手机app和智能设备进行连接，获取设备上的测量数据，我们生活中随处可见的比如蓝牙智能手环，蓝牙电子秤，蓝牙心电测量设备等等。

本篇我将紧接着上篇结尾所写，一起来看下手机之间如何通过蓝牙实现文字聊天。

先贴出上篇的一些demo；

当点击图上的两个列表中的任何一个列表，执行如下代码：


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);
setResult(Activity.RESULT_OK, intent);
finish();

此蓝牙聊天工具最后实现的效果是这样的：

将回到聊天主界面：


public void onActivityResult(int requestCode, int resultCode, Intent data) {
 LogUtils.getInstance().e(getClass(), "onActivityResult " + resultCode);
 switch (requestCode) {
 case REQUEST_CONNECT_DEVICE:
 // 当DeviceListActivity返回与设备连接的消息
 if (resultCode == Activity.RESULT_OK) {
 // 连接设备的MAC地址
 String address = data.getExtras().getString(
 DeviceListActivity.EXTRA_DEVICE_ADDRESS);
 // 得到蓝牙对象
 BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
 // 开始连接设备
 mChatService.connect(device);
 }
 break;
 case REQUEST_ENABLE_BT:
 // 判断蓝牙是否启用
 if (resultCode == Activity.RESULT_OK) {
 // 建立连接
 setupChat();
 } else {
 LogUtils.getInstance().e(getClass(), "蓝牙未启用");
 Toast.makeText(this, R.string.bt_not_enabled_leaving,
 Toast.LENGTH_SHORT).show();
 finish();
 }
 }
}

在此，我将重点介绍下BluetoothChatService类中的连接流程；

因为蓝牙聊天是两个手机之间进行通讯，所以他们互为主机和从机，主要思路以及步骤如下：

1.开一个线程获取socket去连接蓝牙；

2.开一个线程获监听蓝牙传入的连接，如果连接被接受的话，再开启第三个线程去处理所有传入和传出的数据；


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);
}

开线程去连接


/**
 * @description:蓝牙连接线程
 * @author：zzq
 * @time: 2016-8-6 下午1:18:41
 */
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) {
 LogUtils.getInstance().e(getClass(), "socket获取失败：" + e);
 }
 mmSocket = tmp;
 }
 public void run() {
 LogUtils.getInstance().e(getClass(), "开始mConnectThread");
 setName("ConnectThread");
 // mAdapter.cancelDiscovery();
 try {
 mmSocket.connect();
 } catch (IOException e) {
 // 连接失败，更新ui
 connectionFailed();
 try {
 mmSocket.close();
 } catch (IOException e2) {
 LogUtils.getInstance().e(getClass(), "关闭连接失败" + e2);
 }
 // 开启聊天接收线程
 startChat();
 return;
 }
 synchronized (BluetoothChatService.this) {
 mConnectThread = null;
 }
 connected(mmSocket, mmDevice);
 }
 public void cancel() {
 try {
 mmSocket.close();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(), "关闭连接失败" + e);
 }
 }
}


/**
 * 监听传入的连接
 */
private class AcceptThread extends Thread {
private final BluetoothServerSocket mmServerSocket;
 public AcceptThread() {
 BluetoothServerSocket tmp = null;
 try {
 tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(), "--获取socket失败:" + e);
 }
 mmServerSocket = tmp;
 }
 public void run() {
 setName("AcceptThread");
 BluetoothSocket socket = null;
 while (mState != STATE_CONNECTED) {
 LogUtils.getInstance().e(getClass(), "----accept-循环执行中-");
 try {
 socket = mmServerSocket.accept();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(), "accept() 失败" + e);
 break;
 }
// 如果连接被接受
 if (socket != null) {
 synchronized (BluetoothChatService.this) {
 switch (mState) {
 case STATE_LISTEN:
 case STATE_CONNECTING:
 // 开始连接线程
 connected(socket, socket.getRemoteDevice());
 break;
 case STATE_NONE:
 case STATE_CONNECTED:
 // 没有准备好或已经连接
 try {
 socket.close();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(),"不能关闭这些连接" + e);
 }
 break;
 }
 }
 }
}
 LogUtils.getInstance().e(getClass(), "结束mAcceptThread");
}
 public void cancel() {
 LogUtils.getInstance().e(getClass(), "取消 " + this);
 try {
 mmServerSocket.close();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(), "关闭失败" + e);
 }
 }
}
/**
 * 连接成功后的线程 处理所有传入和传出的传输
 */
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;
 // 得到BluetoothSocket输入和输出流
 try {
 tmpIn = socket.getInputStream();
 tmpOut = socket.getOutputStream();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(),"temp sockets not created" + e);
 }
 mmInStream = tmpIn;
 mmOutStream = tmpOut;
 }
 public void run() {
 int bytes;
 String str1 = "";
 // 循环监听消息
 while (true) {
 try {
 byte[] buffer = new byte[256];
 bytes = mmInStream.read(buffer);
 String readStr = new String(buffer, 0, bytes);// 字节数组直接转换成字符串
 String str = bytes2HexString(buffer).replaceAll("00", "").trim();
 if (bytes > 0) {// 将读取到的消息发到主线程
  mHandler.obtainMessage(BluetoothChatActivity.MESSAGE_READ, bytes, -1,buffer).sendToTarget();
 } else {
  LogUtils.getInstance().e(getClass(),"disconnected");
 connectionLost();
 if (mState != STATE_NONE) {
 LogUtils.getInstance().e(getClass(), "disconnected");
startChat();
 }
 break;
 }
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(), "disconnected" + e);
 connectionLost();
 if (mState != STATE_NONE) {
 // 在重新启动监听模式启动该服务
 startChat();
 }
 break;
 }
 }
}
/**
 * 写入OutStream连接
 * 
 * @param buffer
 * 要写的字节
 */
public void write(byte[] buffer) {
 try {
 mmOutStream.write(buffer);
 // 把消息传给UI
 mHandler.obtainMessage(BluetoothChatActivity.MESSAGE_WRITE, -1,-1, buffer).sendToTarget();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(),
"Exception during write:" + e);
 }
 }
public void cancel() {
 try {
 mmSocket.close();
 } catch (IOException e) {
 LogUtils.getInstance().e(getClass(),"close() of connect socket failed:" + e);
 }
 }
 }

大概的流程就是上面三个线程里面所展现的，当然具体情况，根据项目来，比如蓝牙协议协议解析这块的根据协议定义的方式来进行解析;

代码中牵扯的到的蓝牙连接状态的改变，用到的handle，直接把状态发送至activity，通知activity更新；


 /**
 * 无法连接，通知Activity
 */
private void connectionFailed() {
 setState(STATE_LISTEN);
 Message msg = mHandler.obtainMessage(BluetoothChatActivity.MESSAGE_TOAST);
 Bundle bundle = new Bundle();
 bundle.putString(BluetoothChatActivity.TOAST, "无法连接设备");
 msg.setData(bundle);
 mHandler.sendMessage(msg);
}
/**
 * 设备断开连接，通知Activity
 */
private void connectionLost() {
 Message msg = mHandler.obtainMessage(BluetoothChatActivity.MESSAGE_TOAST);
 Bundle bundle = new Bundle();
 bundle.putString(BluetoothChatActivity.TOAST, "设备断开连接");
 msg.setData(bundle);
 mHandler.sendMessage(msg);
}

当点击发送按钮时，将文本输入框中的文字发送数据的方法：


private void sendMessage(String message) {
 if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
 Toast.makeText(this, R.string.not_connected,Toast.LENGTH_SHORT).show();
 return;
}
 if (message.length() > 0) {
 byte[] send = message.getBytes();
 mChatService.write(send);
 }
}
//调用BluetoothChatService类中的write进行数据发送
public void write(byte[] out) {
 ConnectedThread r;
 synchronized (this) {
 if (mState != STATE_CONNECTED)
 return;
 r = mConnectedThread;
 }
 r.write(out);
}

如此，蓝牙聊天的流程就是这样，如果退出聊天的时候，停止所有线程；


public synchronized void stop() {
 LogUtils.getInstance().e(getClass(), "---stop()");
 setState(STATE_NONE);
 if (mConnectThread != null) {
 mConnectThread.cancel();
 mConnectThread = null;
}
 if (mConnectedThread != null) {
 mConnectedThread.cancel();
 mConnectedThread = null;
}
 if (mAcceptThread != null) {
 mAcceptThread.cancel();
 mAcceptThread = null;
 }
}