一、项目内容
使用蓝牙通信，实现通过蓝牙聊天功能
二、项目实现
1.添加蓝牙权限
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />2.activity_main布局
在默认的主布局文件activity_main.xml里，添加1个Toolbar控件，其内包含2个水平的TextView控件；在Toolbar控件的下方添加1个ListView控件，用于显示聊天内容；最后在ListView控件的下方添加水平放置的1个EditText控件和一个Button控件。
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="120dp"
android:layout_weight="1"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
android:theme="?attr/actionBarTheme">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal">
<TextView
android: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:ellipsize="end"
android:gravity="left"
android:singleLine="true"
android:text="TextView" />
<TextView
android: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:text="TextView"
android:textColor="#fff" />
</LinearLayout>
</androidx.appcompat.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" />
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<EditText
android:id="@+id/edit_text_out"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_weight="1"
android:text="text"
android:textSize="20dp" />
<Button android:id="@+id/button_send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/send"/>
</LinearLayout>3.编写用于蓝牙会话的服务组件ChatService
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;
}
@Override
public 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
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;
}
@Override
public 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
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(BluetoothChat.MESSAGE_READ, bytes, -1, buffer).sendToTarget();
} catch (IOException e) {
connectionLost();
break;
}
}
}
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer).sendToTarget();
} catch (IOException e) {
e.printStackTrace();
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}?4.optionmenu.xml和devicelist.xml
分别建立供主Activity使用的菜单文件res/menu/optionmenu.xml、选择好友（即已经配对过的蓝牙设备）的界面布局文件devicelist.xml
option_menu.xml：
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@+id/scan"
android:icon="@android:drawable/ic_menu_myplaces"
android:title="@string/connect" />
<item android:id="@+id/discoverable"
android:icon="@android:drawable/ic_menu_view"
android:title="@string/discoverable" />
<item android:id="@+id/back"
android:icon="@android:drawable/ic_menu_close_clear_cancel"
android:title="@string/back" />
</menu>devicelist.xml:
<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" />5.Activity组件DeviceList
新建Activity组件DeviceList，实现选取与之会话的蓝牙设备
//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() {
@Override
public 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);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_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.activity_device_list);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.activity_device_list);
//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);
}
}
@Override
protected 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
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
init(); //刷新好友列表
}6.蓝牙会话的主Activity组件程序BluetoothChat
检查蓝牙是否可用
if (mBluetoothAdapter == null) {
Toast.makeText(this, "蓝牙不可用", Toast.LENGTH_LONG).show();
finish();
return;
}
if (!mBluetoothAdapter.isEnabled()) { //若当前设备蓝牙功能未开启
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT); //
} else {
if (mChatService == null) {
setupChat(); //创建会话
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if(grantResults.length>0){
if(grantResults[0]!=PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "未授权，蓝牙搜索功能将不可用！", Toast.LENGTH_SHORT).show();
}
}
}使用Handler对象在UI主线程与子线程之间传递消息
private final Handler mHandler = new Handler() { //消息处理
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case ChatService.STATE_CONNECTED:
mTitle.setText(R.string.title_connected_to);
mTitle.append(mConnectedDeviceName);
mConversationArrayAdapter.clear();
break;
case ChatService.STATE_CONNECTING:
mTitle.setText(R.string.title_connecting);
break;
case ChatService.STATE_LISTEN:
case ChatService.STATE_NONE:
mTitle.setText(R.string.title_not_connected);
break;
}
break;
case MESSAGE_WRITE:
byte[] writeBuf = (byte[]) msg.obj;
String writeMessage = new String(writeBuf);
mConversationArrayAdapter.add("我: " + writeMessage);
break;
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf, 0, msg.arg1);
mConversationArrayAdapter.add(mConnectedDeviceName + ": "
+ readMessage);
break;
case MESSAGE_DEVICE_NAME:
mConnectedDeviceName = msg.getData().getString(DEVICE_NAME);
Toast.makeText(getApplicationContext(),"链接到 " + mConnectedDeviceName, Toast.LENGTH_SHORT).show();
break;
case MESSAGE_TOAST:
Toast.makeText(getApplicationContext(),
msg.getData().getString(TOAST), Toast.LENGTH_SHORT).show();
break;
}
}
};返回进入好友列表操作后的数回调方法
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case REQUEST_CONNECT_DEVICE:
if (resultCode == Activity.RESULT_OK) {
String address = data.getExtras().getString(DeviceList.EXTRA_DEVICE_ADDRESS);
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
mChatService.connect(device);
} else if (resultCode == Activity.RESULT_CANCELED) {
Toast.makeText(this, "未选择任何好友！", Toast.LENGTH_SHORT).show();
}
break;
case REQUEST_ENABLE_BT:
if (resultCode == Activity.RESULT_OK) {
setupChat();
} else {
Toast.makeText(this, R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show();
finish();
}
}
}?三、项目结果
?模拟器蓝牙不可用，需用真机调试。
源码地址：myBlueTooth