一、項(xiàng)目實(shí)現(xiàn)功能

1.兩臺(tái)設(shè)備可以通過(guò)藍(lán)牙進(jìn)行通信
2.模擬Client 和Server端實(shí)現(xiàn)簡(jiǎn)單的通信。

二、項(xiàng)目核心代碼

1.簡(jiǎn)要實(shí)現(xiàn)設(shè)備藍(lán)牙通信

如果想讓?xiě)?yīng)用啟動(dòng)設(shè)備發(fā)現(xiàn)或操縱藍(lán)牙設(shè)置，則除了 BLUETOOTH 權(quán)限以外，還必須聲明 BLUETOOTH_ADMIN 權(quán)限。大多數(shù)應(yīng)用只是需利用此權(quán)限發(fā)現(xiàn)本地藍(lán)牙設(shè)備。除非應(yīng)用是根據(jù)用戶(hù)請(qǐng)求修改藍(lán)牙設(shè)置的“超級(jí)管理員”，否則不應(yīng)使用此權(quán)限所授予的其他功能。在Manifest.xml中加入以下代碼

在這里插入代碼片<manifest ... >
  <uses-permission android:name="android.permission.BLUETOOTH" />
  <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

  <!-- If your app targets Android 9 or lower, you can declare
       ACCESS_COARSE_LOCATION instead. -->
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  ...
</manifest>``

布局文件：
activity.xml主要布局

<?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">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme" />

        <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>

    <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="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>

device_list.xm文件

option 布局

java文件：
BluetoothChat.java文件 檢測(cè)藍(lán)牙是否授權(quán)，啟動(dòng)的activity文件

package com.example.bluetooth;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.MenuItem;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Toolbar;


public class BluetoothChat extends AppCompatActivity{
    public static final int MESSAGE_STATE_CHANGE = 1;
    public static final int MESSAGE_READ = 2;
    public static final int MESSAGE_WRITE = 3;
    public static final int MESSAGE_DEVICE_NAME = 4;
    public static final int MESSAGE_TOAST = 5;
    public static final String DEVICE_NAME = "device_name";
    public static final String TOAST = "toast";
    private static final int REQUEST_CONNECT_DEVICE = 1;  //請(qǐng)求連接設(shè)備
    private static final int REQUEST_ENABLE_BT = 2;
    private TextView title;
    private ListView conversationView;
    private EditText outEditText;
    private Button send;
    private String connectedDeviceName = null;
    private ArrayAdapter<String> adapter1;     // conversation array adapter
    private StringBuffer outStringBuffer;
    private BluetoothAdapter adapter2 = null;
    private ChatService chatService = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getSupportActionBar().hide();  //隱藏標(biāo)題欄
        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);
        //創(chuàng)建選項(xiàng)菜單
        toolbar.inflateMenu(R.menu.option_menu);
        //選項(xiàng)菜單監(jiān)聽(tīng)
        toolbar.setOnMenuItemClickListener(new MyMenuItemClickListener());
        title = findViewById(R.id.title_left_text);
        title.setText(R.string.app_name);
        title = findViewById(R.id.title_right_text);
        // 得到本地藍(lán)牙適配器
        adapter2 = BluetoothAdapter.getDefaultAdapter();

        if (adapter2 == null) {
            Toast.makeText(this, "藍(lán)牙不可用", Toast.LENGTH_LONG).show();
            finish();
            return;
        }
        if (!adapter2.isEnabled()) { //若當(dāng)前設(shè)備藍(lán)牙功能未開(kāi)啟
            Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableIntent, REQUEST_ENABLE_BT); //
        } else {
            if (chatService == null) {
                setupChat();  //創(chuàng)建會(huì)話
            }
        }
    }
    
    @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, "未授權(quán)，藍(lán)牙搜索功能將不可用！", Toast.LENGTH_SHORT).show();
            }
        }
    }
    @Override
    public synchronized void onResume() {  //synchronized：同步方法實(shí)現(xiàn)排隊(duì)調(diào)用
        super.onResume();
        if (chatService != null) {
            if (chatService.getState() == ChatService.STATE_NONE) {
                chatService.start();
            }
        }
    }
    private void setupChat() {
        adapter1 = new ArrayAdapter<String>(this, R.layout.activity_main);
        conversationView = findViewById(R.id.in);
        conversationView.setAdapter(adapter1);
        outEditText = findViewById(R.id.edit_text_out);
        outEditText.setOnEditorActionListener(mWriteListener);
        send = findViewById(R.id.button_send);
        send.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                TextView view = findViewById(R.id.edit_text_out);
                String message = view.getText().toString();
                sendMessage(message);
            }
        });
        //創(chuàng)建服務(wù)對(duì)象
        chatService = new ChatService(this, mHandler);
        outStringBuffer = new StringBuffer("");
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        if (chatService != null)
            chatService.stop();
    }

    // 直接使用enable()函數(shù)不安全，需要將內(nèi)容存放在intent中
    private void ensureDiscoverable() { //修改本機(jī)藍(lán)牙設(shè)備的可見(jiàn)性
        //打開(kāi)手機(jī)藍(lán)牙后，能被其它藍(lán)牙設(shè)備掃描到的時(shí)間不是永久的
        if (adapter2.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
            Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
            //設(shè)置在300秒內(nèi)可見(jiàn)（能被掃描）
            discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
            startActivity(discoverableIntent);
            Toast.makeText(this, "已經(jīng)設(shè)置本機(jī)藍(lán)牙設(shè)備的可見(jiàn)性，對(duì)方可搜索了。", Toast.LENGTH_SHORT).show();
        }
    }


    private void sendMessage(String message) {
        if (chatService.getState() != ChatService.STATE_CONNECTED) {
            Toast.makeText(this, R.string.not_connected, Toast.LENGTH_SHORT).show();
            return;
        }
        if (message.length() > 0) {
            byte[] send = message.getBytes();
            chatService.write(send);
            outStringBuffer.setLength(0);
            outEditText.setText(outStringBuffer);
        }
    }


    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) {
                //軟鍵盤(pán)里的回車(chē)也能發(fā)送消息
                String message = view.getText().toString();
                sendMessage(message);
            }
            return true;
        }
    };


    //使用Handler對(duì)象在UI主線程與子線程之間傳遞消息
    private final Handler mHandler = new Handler() {   //消息處理
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MESSAGE_STATE_CHANGE:
                    switch (msg.arg1) {
                        case ChatService.STATE_CONNECTED:
                            title.setText(R.string.title_connected_to);
                            title.append(connectedDeviceName);
                            adapter1.clear();
                            break;
                        case ChatService.STATE_CONNECTING:
                            title.setText(R.string.title_connecting);
                            break;
                        case ChatService.STATE_LISTEN:
                        case ChatService.STATE_NONE:
                            title.setText(R.string.title_not_connected);
                            break;
                    }
                    break;
                case MESSAGE_WRITE:
                    byte[] writeBuf = (byte[]) msg.obj;
                    String writeMessage = new String(writeBuf);
                    adapter1.add("我:  " + writeMessage);
                    break;
                case MESSAGE_READ:
                    byte[] readBuf = (byte[]) msg.obj;
                    String readMessage = new String(readBuf, 0, msg.arg1);
                    adapter1.add(connectedDeviceName + ":  "
                            + readMessage);
                    break;
                case MESSAGE_DEVICE_NAME:
                    connectedDeviceName = msg.getData().getString(DEVICE_NAME);
                    Toast.makeText(getApplicationContext(),"鏈接到 " + connectedDeviceName, Toast.LENGTH_SHORT).show();
                    break;
                case MESSAGE_TOAST:
                    Toast.makeText(getApplicationContext(),
                            msg.getData().getString(TOAST), Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    };


    //返回進(jìn)入好友列表操作后的數(shù)回調(diào)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 = adapter2.getRemoteDevice(address);
                    chatService.connect(device);
                } else if (resultCode == Activity.RESULT_CANCELED) {
                    Toast.makeText(this, "未選擇任何好友！", 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();
                }
        }
    }


    //內(nèi)部類(lèi)，選項(xiàng)菜單的單擊事件處理
    private class MyMenuItemClickListener implements Toolbar.OnMenuItemClickListener {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.scan:
                    //啟動(dòng)DeviceList這個(gè)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;
        }
    }
}

ChatService.java文件，藍(lán)牙服務(wù)的會(huì)話程序 定義了3個(gè)內(nèi)部類(lèi)，AcceptThread（接受新連接）、ConnectThread（發(fā)出連接）和ConnectedThread （已連接）

package com.example.bluetooth;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;



public class ChatService {
    //本應(yīng)用的主Activity組件名稱(chēng)
    private static final String NAME = "BluetoothChat";
    // UUID：通用唯一識(shí)別碼,是一個(gè)128位長(zhǎng)的數(shù)字，一般用十六進(jìn)制表示
    //算法的核心思想是結(jié)合機(jī)器的網(wǎng)卡、當(dāng)?shù)貢r(shí)間、一個(gè)隨機(jī)數(shù)來(lái)生成
    //在創(chuàng)建藍(lán)牙連接
    private static final UUID MY_UUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
    private final BluetoothAdapter adapter;
    private final Handler mHandler;
    private AcceptThread acceptThread;
    private ConnectThread connectThread;
    private ConnectedThread connectedThread;
    private int state;
    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;

    //構(gòu)造方法，接收UI主線程傳遞的對(duì)象
    public ChatService(Context context, Handler handler) {
        //構(gòu)造方法完成藍(lán)牙對(duì)象的創(chuàng)建
        adapter = BluetoothAdapter.getDefaultAdapter();
        state = STATE_NONE;
        mHandler = handler;
    }

    private synchronized void setState(int state) {
        state = state;
        mHandler.obtainMessage(BluetoothChat.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }

    public synchronized int getState() {
        return state;
    }

    public synchronized void start() {
        if (connectThread != null) {
            connectThread.cancel();
            connectThread = null;
        }
        if (connectedThread != null) {
            connectedThread.cancel();
            connectedThread = null;
        }
        if (acceptThread == null) {
            acceptThread = new AcceptThread();
            acceptThread.start();
        }
        setState(STATE_LISTEN);
    }

    //取消 CONNECTING 和 CONNECTED 狀態(tài)下的相關(guān)線程，然后運(yùn)行新的 connectThread 線程
    public synchronized void connect(BluetoothDevice device) {
        if (state == STATE_CONNECTING) {
            if (connectThread != null) {
                connectThread.cancel();
                connectThread = null;
            }
        }
        if (connectedThread != null) {
            connectedThread.cancel();
            connectedThread = null;
        }
        connectThread = new ConnectThread(device);
        connectThread.start();
        setState(STATE_CONNECTING);
    }

    /*
        開(kāi)啟一個(gè) ConnectedThread 來(lái)管理對(duì)應(yīng)的當(dāng)前連接。之前先取消任意現(xiàn)存的 connectThread 、
        connectedThread 、 acceptThread 線程，然后開(kāi)啟新 connectedThread ，傳入當(dāng)前剛剛接受的
        socket 連接。最后通過(guò) Handler來(lái)通知UI連接
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
        if (connectThread != null) {
            connectThread.cancel();
            connectThread = null;
        }
        if (connectedThread != null) {
            connectedThread.cancel();
            connectedThread = null;
        }
        if (acceptThread != null) {
            acceptThread.cancel();
            acceptThread = null;
        }
        connectedThread = new ConnectedThread(socket);
        connectedThread.start();
        Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothChat.DEVICE_NAME, device.getName());
        msg.setData(bundle);
        mHandler.sendMessage(msg);
        setState(STATE_CONNECTED);
    }

    // 停止所有相關(guān)線程，設(shè)當(dāng)前狀態(tài)為 NONE
    public synchronized void stop() {
        if (connectThread != null) {
            connectThread.cancel();
            connectThread = null;
        }
        if (connectedThread != null) {
            connectedThread.cancel();
            connectedThread = null;
        }
        if (acceptThread != null) {
            acceptThread.cancel();
            acceptThread = null;
        }
        setState(STATE_NONE);
    }

    // 在 STATE_CONNECTED 狀態(tài)下，調(diào)用 connectedThread 里的 write 方法，寫(xiě)入 byte
    public void write(byte[] out) {
        ConnectedThread r;
        synchronized (this) {
            if (state != STATE_CONNECTED)
                return;
            r = connectedThread;
        }
        r.write(out);
    }

    // 連接失敗的時(shí)候處理，通知 ui ，并設(shè)為 STATE_LISTEN 狀態(tài)
    private void connectionFailed() {
        setState(STATE_LISTEN);
        Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothChat.TOAST, "鏈接不到設(shè)備");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    // 當(dāng)連接失去的時(shí)候，設(shè)為 STATE_LISTEN 狀態(tài)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, "設(shè)備鏈接中斷");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    // 創(chuàng)建監(jiān)聽(tīng)線程，準(zhǔn)備接受新連接。使用阻塞方式，調(diào)用 BluetoothServerSocket.accept()
    private class AcceptThread extends Thread {
        private final BluetoothServerSocket mmServerSocket;

        public AcceptThread() {
            BluetoothServerSocket tmp = null;
            try {
                //使用射頻端口（RF comm）監(jiān)聽(tīng)
                tmp = adapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }

        @Override
        public void run() {
            setName("AcceptThread");
            BluetoothSocket socket = null;
            while (state != STATE_CONNECTED) {
                try {
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }
                if (socket != null) {
                    synchronized (ChatService.this) {
                        switch (state) {
                            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();
            }
        }
    }

    /*
        連接線程，專(zhuān)門(mén)用來(lái)對(duì)外發(fā)出連接對(duì)方藍(lán)牙的請(qǐng)求和處理流程。
        構(gòu)造函數(shù)里通過(guò) BluetoothDevice.createRfcommSocketToServiceRecord() ，
        從待連接的 device 產(chǎn)生 BluetoothSocket. 然后在 run 方法中 connect ，
        成功后調(diào)用 BluetoothChatSevice 的 connected() 方法。定義 cancel() 在關(guān)閉線程時(shí)能夠關(guān)閉相關(guān)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");
            adapter.cancelDiscovery();
            try {
                mmSocket.connect();
            } catch (IOException e) {
                connectionFailed();
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                    e.printStackTrace();
                }
                ChatService.this.start();
                return;
            }
            synchronized (ChatService.this) {
                connectThread = null;
            }
            connected(mmSocket, mmDevice);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /*
        雙方藍(lán)牙連接后一直運(yùn)行的線程；構(gòu)造函數(shù)中設(shè)置輸入輸出流。
        run()方法中使用阻塞模式的 InputStream.read()循環(huán)讀取輸入流，然后發(fā)送到 UI 線程中更新聊天消息。
        本線程也提供了 write() 將聊天消息寫(xiě)入輸出流傳輸至對(duì)方，傳輸成功后回寫(xiě)入 UI 線程。最后使用cancel()關(guān)閉連接的 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();
            }
        }
    }
}

DeviceList.java文件
本程序供菜單項(xiàng)主界面的選項(xiàng)菜單“我的友好”調(diào)用，用于：
（1）顯示已配對(duì)的好友列表；
（2）搜索可配對(duì)的好友進(jìn)行配對(duì)
（3）新選擇并配對(duì)的藍(lán)牙設(shè)備將刷新好友列表
注意：發(fā)現(xiàn)新的藍(lán)牙設(shè)備并請(qǐng)求配對(duì)時(shí)，需要對(duì)應(yīng)接受
關(guān)鍵技術(shù)：動(dòng)態(tài)注冊(cè)一個(gè)廣播接收者，處理藍(lán)牙設(shè)備掃描的結(jié)果

package com.example.bluetooth;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.provider.Settings;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Set;

public class DeviceList extends AppCompatActivity {
    private BluetoothAdapter adapter;
    private ArrayAdapter<String> adapter1;    // 配對(duì)的設(shè)備
    private ArrayAdapter<String> adapter2;       // 新設(shè)備
    public static String EXTRA_DEVICE_ADDRESS = "device_address";  //Mac地址
    //定義廣播接收者，用于處理掃描藍(lán)牙設(shè)備后的結(jié)果
    private final BroadcastReceiver receiver = 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) {
                    adapter2.add(device.getName() + "\n" + device.getAddress());
                }
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                if (adapter2.getCount() == 0) {
                    String noDevices = getResources().getText(R.string.none_found).toString();
                    adapter2.add(noDevices);
                }
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.device_list);
        //在被調(diào)用活動(dòng)里，設(shè)置返回結(jié)果碼
        setResult(Activity.RESULT_CANCELED);
        init();  //活動(dòng)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();  //搜索藍(lán)牙設(shè)備
            }
        });
        adapter1 = new ArrayAdapter<String>(this, R.layout.activity_main);
        adapter2 = new ArrayAdapter<String>(this, R.layout.activity_main);
        //已配對(duì)藍(lán)牙設(shè)備列表
        ListView pairedListView =findViewById(R.id.paired_devices);
        pairedListView.setAdapter(adapter1);
        pairedListView.setOnItemClickListener(mPaireDeviceClickListener);
        //未配對(duì)藍(lán)牙設(shè)備列表
        ListView newDevicesListView = findViewById(R.id.new_devices);
        newDevicesListView.setAdapter(adapter2);
        newDevicesListView.setOnItemClickListener(mNewDeviceClickListener);
        //動(dòng)態(tài)注冊(cè)廣播接收者
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(receiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        registerReceiver(receiver, filter);
        adapter = BluetoothAdapter.getDefaultAdapter();
        Set<BluetoothDevice> pairedDevices = adapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
            for (BluetoothDevice device : pairedDevices) {
                adapter1.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String noDevices = getResources().getText(R.string.none_paired).toString();
            adapter1.add(noDevices);
        }
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (adapter != null) {
            adapter.cancelDiscovery();
        }
        this.unregisterReceiver(receiver);
    }
    private void doDiscovery() {
        findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
        if (adapter.isDiscovering()) {
            adapter.cancelDiscovery();
        }
        adapter.startDiscovery();  //開(kāi)始搜索藍(lán)牙設(shè)備并產(chǎn)生廣播
        //startDiscovery是一個(gè)異步方法
        //找到一個(gè)設(shè)備時(shí)就發(fā)送一個(gè)BluetoothDevice.ACTION_FOUND的廣播
    }
    private AdapterView.OnItemClickListener mPaireDeviceClickListener = new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            adapter.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) {
            adapter.cancelDiscovery();
            Toast.makeText(DeviceList.this, "請(qǐng)?jiān)谒{(lán)牙設(shè)置界面手動(dòng)連接設(shè)備",Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(Settings.ACTION_BLUETOOTH_SETTINGS);
            startActivityForResult(intent,1);
        }
    };
    //回調(diào)方法：進(jìn)入藍(lán)牙配對(duì)設(shè)置界面返回后執(zhí)行
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        init();  //刷新好友列表
    }
}

2.模擬Client 和Server端實(shí)現(xiàn)簡(jiǎn)單的通信。

Client端 布局文件
button用以開(kāi)關(guān)藍(lán)牙以及搜索設(shè)備的布局按鈕

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/lis1"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <ToggleButton
            android:id="@+id/bu5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="ToggleButton" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="本機(jī)狀態(tài)：" />

        <Button
            android:id="@+id/button4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="搜索設(shè)備" />

        <Button
            android:id="@+id/button3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="設(shè)置" />

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="打開(kāi)" />
    </ListView>


</LinearLayout>

mainactivity.java

package com.example.gwlblu;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.ToggleButton;

import androidx.appcompat.app.AppCompatActivity;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {
    //藍(lán)牙通信需要相同的UUID和對(duì)方的藍(lán)牙地址，UUID規(guī)定是下面的格式，只要格式對(duì)，兩邊的UUID相同，數(shù)字可以改變，不影響通信，但一般都是用下面這種
    static final String SPP_UUID = "00001101-0000-1000-8000-00805F9B34FB";
    Button btnSearch, btnDis;//定義布局中的按鈕
    ToggleButton tbtnSwitch;//顯示藍(lán)牙開(kāi)關(guān)狀態(tài)的雙狀態(tài)按鈕
    ListView lvBTDevices; //搜索到的藍(lán)牙列表
    ArrayAdapter<String> adtDevices; //將本機(jī)的藍(lán)牙地址顯示
    List<String> lstDevices = new ArrayList<String>();//列表中藍(lán)牙的地址
    BluetoothAdapter btAdapt;  //定義移動(dòng)設(shè)備的本地的藍(lán)牙適配器
    public static BluetoothSocket btSocket;  //Socket用來(lái)接受客戶(hù)端的要求

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main); //加載 布局

        // Button 設(shè)置 通過(guò)findViewById的方法來(lái)定義
        //獲得所有控件對(duì)象
        btnSearch = (Button) this.findViewById(R.id.button2);
        btnDis = (Button) this.findViewById(R.id.button3);
        tbtnSwitch = (ToggleButton) this.findViewById(R.id.bu5);

        //給所有的控件設(shè)置監(jiān)聽(tīng)器
        btnDis.setOnClickListener(new ClickEvent());
        btnSearch.setOnClickListener(new ClickEvent());
        tbtnSwitch.setOnClickListener(new ClickEvent());

        // ListView及其數(shù)據(jù)源 適配器
        lvBTDevices = (ListView) this.findViewById(R.id.lis1);
        adtDevices = new ArrayAdapter<String>(MainActivity.this,
                android.R.layout.simple_list_item_1, lstDevices);
        lvBTDevices.setAdapter(adtDevices);
        lvBTDevices.setOnItemClickListener(new ItemClickEvent());//設(shè)置監(jiān)聽(tīng)器獲取數(shù)據(jù)

        btAdapt = BluetoothAdapter.getDefaultAdapter();// 初始化本機(jī)藍(lán)牙功能

        if (btAdapt.getState() == BluetoothAdapter.STATE_OFF)// 讀取藍(lán)牙狀態(tài)并顯示于雙狀態(tài)按鈕
            tbtnSwitch.setChecked(false);
        else if (btAdapt.getState() == BluetoothAdapter.STATE_ON)
            tbtnSwitch.setChecked(true);

        // 注冊(cè)Receiver來(lái)獲取藍(lán)牙設(shè)備相關(guān)的結(jié)果，onReceive()里取得搜索所得的藍(lán)牙設(shè)備信息
        IntentFilter intent = new IntentFilter();
        intent.addAction(BluetoothDevice.ACTION_FOUND);// 用BroadcastReceiver來(lái)取得搜索結(jié)果
        intent.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        intent.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
        intent.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        registerReceiver(searchDevices, intent);
    }


    private BroadcastReceiver searchDevices = new BroadcastReceiver() {

        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Bundle b = intent.getExtras();
            Object[] lstName = b.keySet().toArray();

            // 顯示所有收到的消息及其細(xì)節(jié)
            for (int i = 0; i < lstName.length; i++) {
                String keyName = lstName[i].toString();
                Log.e(keyName, String.valueOf(b.get(keyName)));
            }
            //搜索設(shè)備時(shí)，取得設(shè)備的MAC地址
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                String str= device.getName() + "|" + device.getAddress();
                if (lstDevices.indexOf(str) == -1)// 防止重復(fù)添加，
                    lstDevices.add(str); // 獲取設(shè)備名稱(chēng)和mac地址
                adtDevices.notifyDataSetChanged();//通知Activity刷新數(shù)據(jù)
            }
        }
    };

    //本次活動(dòng)的銷(xiāo)毀函數(shù)
    @Override
    protected void onDestroy() {
        try {
            if (btSocket != null)
                btSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        this.unregisterReceiver(searchDevices);
        super.onDestroy();
        android.os.Process.killProcess(android.os.Process.myPid());
    }
    //對(duì)監(jiān)聽(tīng)器的設(shè)置，獲取列表中設(shè)備名以及藍(lán)牙設(shè)備地址
    class ItemClickEvent implements AdapterView.OnItemClickListener {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                                long arg3) {
            btAdapt.cancelDiscovery();//連接時(shí)停止搜索周?chē){(lán)牙，否則容易連接失敗
            //取出藍(lán)牙地址
            String str = lstDevices.get(arg2);
            String[] values = str.split("\\|");
            String address=values[1];
            Log.d("address",values[1]);
            UUID uuid = UUID.fromString(SPP_UUID);

            //利用BluetoothDevice衍生出Socket,
            BluetoothDevice btDev = btAdapt.getRemoteDevice(address);
            try {
                btSocket = btDev
                        .createRfcommSocketToServiceRecord(uuid);

                try {
                    // 連接建立之前的先配對(duì)
                    if (btDev.getBondState() == BluetoothDevice.BOND_NONE) {
                        Method creMethod = BluetoothDevice.class
                                .getMethod("createBond");
                        Log.e("TAG", "開(kāi)始配對(duì)");
                        creMethod.invoke(btDev);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
                btSocket.connect();
                Toast.makeText(MainActivity.this,"connect succeeded",Toast.LENGTH_SHORT).show();

                //將數(shù)據(jù)寫(xiě)入輸出流
                OutputStream os = btSocket.getOutputStream();
                if (os != null) {
                    try {
                        os.write("test".getBytes("UTF-8"));
                        Toast.makeText(MainActivity.this, "send succeed", Toast.LENGTH_LONG).show();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

            } catch (IOException e) {
                e.printStackTrace();
                Toast.makeText(MainActivity.this,"connect fail",Toast.LENGTH_LONG).show();
            }

        }
    }


    //按鈕監(jiān)聽(tīng)器，打開(kāi)本機(jī)藍(lán)牙的設(shè)置
    class ClickEvent implements View.OnClickListener {
        @Override
        public void onClick(View v) {
            if (v == btnSearch)// 搜索藍(lán)牙設(shè)備，在BroadcastReceiver顯示結(jié)果
            {
                if (btAdapt.getState() == BluetoothAdapter.STATE_OFF) {// 如果藍(lán)牙還沒(méi)開(kāi)啟
                    Toast.makeText(MainActivity.this, "請(qǐng)先打開(kāi)藍(lán)牙", Toast.LENGTH_LONG).show();
                    return;
                }
                setTitle("本機(jī)藍(lán)牙地址：" + btAdapt.getAddress());
                lstDevices.clear();
                btAdapt.startDiscovery();
            } else if (v == tbtnSwitch) {// 本機(jī)藍(lán)牙啟動(dòng)/關(guān)閉
                if (tbtnSwitch.isChecked() == false)
                    btAdapt.enable();
                else if (tbtnSwitch.isChecked() == true)
                    btAdapt.disable();
            } else if (v == btnDis)// 本機(jī)可以被搜索
            {
                Intent discoverableIntent = new Intent(
                        BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
                discoverableIntent.putExtra(
                        BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
                startActivity(discoverableIntent);//本機(jī)藍(lán)牙的內(nèi)部設(shè)置
            }
        }
    }
}

Server端

package com.example.gwlblu;

import androidx.appcompat.app.AppCompatActivity;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.Toast;

import java.io.InputStream;
import java.util.UUID;

public class Server extends AppCompatActivity {
    private final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");//Server端和Client端的UUID要一致
    private BluetoothAdapter bluetoothAdapter;
    private final String NAME = "BlueTooth_Socket";//名字可以隨便寫(xiě)

    private AcceptThread acceptThread;//后面的accept（）會(huì)阻塞，所以要新開(kāi)線程


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_server);
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        acceptThread=new AcceptThread();
        acceptThread.start();//開(kāi)啟線程
    }


    private Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            Toast.makeText(Server.this, String.valueOf(msg.obj), Toast.LENGTH_SHORT).show();
        }
    };

    private class AcceptThread extends Thread {
        private BluetoothServerSocket serverSocket;
        private BluetoothSocket socket;
        private InputStream is;

        public AcceptThread() {
            try {
                //監(jiān)聽(tīng)有無(wú)連接
                serverSocket = bluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
            } catch (Exception e) {
            }
        }

        @Override
        public void run() {
            try {
                socket = serverSocket.accept();//若有監(jiān)聽(tīng)到有連接，accept給BluetoothSocket
                Log.d("tag", "connected");

                is = socket.getInputStream();

                while (true) {
                    byte[] buffer = new byte[128];
                    int count = is.read(buffer);
                    //子線程里不能直接Toast，利用handler
                    Message msg = new Message();
                    msg.obj = new String(buffer, 0, count, "UTF-8");
                    handler.sendMessage(msg);
                }
            } catch (Exception e) {

            }
        }
    }
}

三、實(shí)驗(yàn)項(xiàng)目截圖

實(shí)驗(yàn)1（真機(jī)調(diào)試）：
簡(jiǎn)單實(shí)現(xiàn)藍(lán)牙通信聊天


實(shí)驗(yàn)2
實(shí)現(xiàn)功能：Client端三個(gè)按鈕，分別是藍(lán)牙開(kāi)關(guān)、本機(jī)可被搜索和搜索設(shè)備，點(diǎn)擊搜索設(shè)備即可搜索周?chē)乃{(lán)牙，點(diǎn)擊搜索到的藍(lán)牙即可連接并自動(dòng)發(fā)送test。Server端在接收到消息之后便Toast出來(lái)。

四、源代碼

gitee源代碼1
gitee源代碼2文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-435839.html

到了這里，關(guān)于Android Studio 簡(jiǎn)要實(shí)現(xiàn)藍(lán)牙（Bluetooth）通信（附加作業(yè)）的文章就介紹完了。如果您還想了解更多內(nèi)容，請(qǐng)?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！