实验目的
在app中实现蓝牙通信
主要代码
新建工程BlueTooth，在AndroidManifest.xml中添加权限申请
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />界面设计activity_main
<?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"
android:background="@color/blue">
<!--新版Android支持的Toolbar，对标题栏布局-->
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
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:gravity="left"
android:ellipsize="end"
android:singleLine="true" />
<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: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" >
</ListView>
<LinearLayout
android: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>编写蓝牙服务文件
setState(STATE_CONNECTED);
}
// 停止所有相关线程，设当前状态为 NONE
public 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 byte
public 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(BluetoothChat.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(BluetoothChat.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 ui
private void connectionLost() {
setState(STATE_LISTEN);
Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(BluetoothChat.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;
}
@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。
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;
}
@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。
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(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();
}
}
}
}Mainactivty
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportActionBar().hide(); //隐藏标题栏
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
}
}
Toolbar toolbar = findViewById(R.id.toolbar);
//创建选项菜单
toolbar.inflateMenu(R.menu.option_menu);
//选项菜单监听
toolbar.setOnMenuItemClickListener(new MyMenuItemClickListener());
mTitle = findViewById(R.id.title_left_text);
mTitle.setText(R.string.app_name);
mTitle = findViewById(R.id.title_right_text);
// 得到本地蓝牙适配器
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
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，蓝牙搜索功能不可食用！", Toast.LENGTH_SHORT).show();
}
}
}
@Override
public synchronized void onResume() { //synchronized：同步方法实现排队调用
super.onResume();
if (mChatService != null) {
if (mChatService.getState() == ChatService.STATE_NONE) {
mChatService.start();
}
}
}
private void setupChat() {
mConversationArrayAdapter = new ArrayAdapter<String>(this, R.layout.activity_main);
mConversationView = findViewById(R.id.in);
mConversationView.setAdapter(mConversationArrayAdapter);
mOutEditText = findViewById(R.id.edit_text_out);
mOutEditText.setOnEditorActionListener(mWriteListener);
mSendButton = findViewById(R.id.button_send);
mSendButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
TextView view = findViewById(R.id.edit_text_out);
String message = view.getText().toString();
sendMessage(message);
}
});
//创建服务对象
mChatService = new ChatService(this, mHandler);
mOutStringBuffer = new StringBuffer("");
}
@Override
public void onDestroy() {
super.onDestroy();
if (mChatService != null)
mChatService.stop();
}
private void ensureDiscoverable() { //修改本机蓝牙设备的可见性
//打开手机蓝牙后，能被其它蓝牙设备扫描到的时间不是永久的
if (mBluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
//设置在300秒内可见（能被扫描）
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
Toast.makeText(this, "已经设置本机蓝牙设备的可见性，对方可搜索了。", Toast.LENGTH_SHORT).show();
}
}
private void sendMessage(String message) {
if (mChatService.getState() != ChatService.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);
mOutStringBuffer.setLength(0);
mOutEditText.setText(mOutStringBuffer);
}
}
private TextView.OnEditorActionListener mWriteListener = new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
//软键盘里的回车也能发送消息
String message = view.getText().toString();
sendMessage(message);
}
return true;
}
};
//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();
}
}
}
//内部类，选项菜单的单击事件处理
private class MyMenuItemClickListener implements Toolbar.OnMenuItemClickListener {
@Override
public boolean onMenuItemClick(MenuItem item) {
switch (item.getItemId()) {
case R.id.scan:
//启动DeviceList这个Activity
Intent serverIntent = new Intent(BluetoothChat.this, DeviceList.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE);
return true;
case R.id.discoverable:
ensureDiscoverable();
return true;
case R.id.back:
finish();
System.exit(0);
return true;
}
return false;
}
}
}用usb线连接手机并允许手机进行文件传送，在系统设置中打开开发者模式
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android studio中显示出你的手机后点击运行，app会自动下载到手机上并运行
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最终结果：
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