Android实现蓝牙聊天功能

2020-11-05 09:41:34 浏览数 (3)

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:

代码语言:javascript复制
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:

代码语言:javascript复制
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;

代码语言:javascript复制
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

代码语言:javascript复制
/**
 * @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);
 }
 }
}
代码语言:javascript复制
/**
* 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;

代码语言:javascript复制
/**
* 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:

代码语言:javascript复制
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;

代码语言:javascript复制
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;
}
}

相信看完本篇文章,在安卓蓝牙连接这块应该问题不大了(spp协议)。

源码地址:点我查看源码

以上就是本文的全部内容,希望对大家的学习有所帮助。

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