移动开发作业六蓝牙通信

一、蓝牙通信的步骤

开启蓝牙
搜索可用设备
创建蓝牙socket
获取输入输出流
断开连接关闭蓝牙

二、几个重要的类

BluetoothAdapter
BluetoothGatt
BluetoothDevice
BluetoothCattService
BluetoothCattCharacteristic

第一个是蓝牙设配器，对蓝牙的操作都需要用到它，很重要，BluetoothGatt作为中央来使用和处理数据，使用时有一个回调方法BluetoothGattCallback返回中央的状态和周边提供的数据，BluetoothCattService作为周边来提供数据；BluetoothGattServerCallback返回周边的状态。BluetoothDevice是蓝牙设备，BluetoothCattCharacteristic是蓝牙设备的特征。

看着有点乱，我们来打个比喻：BluetoothDevice为学校，BluetoothGatt为学校到达某一个班级的通道，BluetoothCattService为学校的某一个班级，BluetoothCattCharacteristic为班级中的某一个学生。那么蓝牙连接通信的过程就是这样，BluetoothAdapter先找到学校（就是连接目的设备），再通过通道找到目标班级，最后从班级中找到目标学生，这个学生就是我们设备之间通信的中介，很重要，学校有唯一的MAC地址，班级有唯一的serviceUUID，学生有唯一的charactersticUUID（相当于学号），所以就是在一所学校找一个学生的问题。

三、蓝牙通信的原理

3.1 蓝牙通信原理与socket通信原理相似

3.2 客户端socket

创建客户端蓝牙Socket
创建连接
读写数据
关闭

3.3 服务端Socket

创建服务端蓝牙Socket
绑定端口号（蓝牙忽略）
创建监听listen（蓝牙忽略, 蓝牙没有此监听，而是通过while（true）死循环来一直监听的）
通过accept()，如果有客户端连接，会创建一个新的Socket，体现出并发性，可以同时与多个socket通讯）
读写数据
关闭

四、客户端代码

public class ConnectThread extends Thread{private static final UUID MY_UUID = UUID.fromString(Constant.CONNECTTION_UUID);/** 客户端socket*/private final BluetoothSocket mmSoket;/** 要连接的设备*/private final BluetoothDevice mmDevice;private BluetoothAdapter mBluetoothAdapter;/** 主线程通信的Handler*/private final Handler mHandler;/** 发送和接收数据的处理类*/private ConnectedThread mConnectedThread;public ConnectThread(BluetoothDevice device, BluetoothAdapter bluetoothAdapter, Handler mUIhandler) {mmDevice = device;mBluetoothAdapter = bluetoothAdapter;mHandler = mUIhandler;BluetoothSocket tmp = null;try {// 创建客户端Sockettmp = device.createRfcommSocketToServiceRecord(MY_UUID);} catch (IOException e) {e.printStackTrace();}mmSoket = tmp;}@Overridepublic void run() {super.run();// 关闭正在发现设备.(如果此时又在查找设备，又在发送数据，会有冲突，影响传输效率)mBluetoothAdapter.cancelDiscovery();try {// 连接服务器mmSoket.connect();} catch (IOException e) {// 连接异常就关闭try {mmSoket.close();} catch (IOException e1) {}return;}manageConnectedSocket(mmSoket);}private void manageConnectedSocket(BluetoothSocket mmSoket) {// 通知主线程连接上了服务端socket，更新UImHandler.sendEmptyMessage(Constant.MSG_CONNECTED_TO_SERVER);// 新建一个线程进行通讯,不然会发现线程堵塞mConnectedThread = new ConnectedThread(mmSoket,mHandler);mConnectedThread.start();}/*** 关闭当前客户端*/public void cancle() {try {mmSoket.close();} catch (IOException e) {e.printStackTrace();}}/*** 发送数据* @param data*/public void sendData(byte[] data) {if(mConnectedThread != null) {mConnectedThread.write(data);}}
}

五、服务端代码

public class AccepThread extends Thread {/** 连接的名称*/private static final String NAME = "BluetoothClass";/** UUID*/private static final UUID MY_UUID = UUID.fromString(Constant.CONNECTTION_UUID);/** 服务端蓝牙Sokcet*/private final BluetoothServerSocket mmServerSocket;private final BluetoothAdapter mBluetoothAdapter;/** 线程中通信的更新UI的Handler*/private final Handler mHandler;/** 监听到有客户端连接，新建一个线程单独处理，不然在此线程中会堵塞*/private ConnectedThread mConnectedThread;public AccepThread(BluetoothAdapter adapter, Handler handler) throws IOException {mBluetoothAdapter = adapter;this.mHandler = handler;// 获取服务端蓝牙socketmmServerSocket = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);}@Overridepublic void run() {super.run();// 连接的客户端soacketBluetoothSocket socket = null;// 服务端是不退出的,要一直监听连接进来的客户端，所以是死循环while (true){// 通知主线程更新UI,客户端开始监听mHandler.sendEmptyMessage(Constant.MSG_START_LISTENING);try {// 获取连接的客户端socketsocket =  mmServerSocket.accept();} catch (IOException e) {// 通知主线程更新UI, 获取异常mHandler.sendEmptyMessage(Constant.MSG_ERROR);e.printStackTrace();// 服务端退出一直监听线程break;}if(socket != null) {// 管理连接的客户端socketmanageConnectSocket(socket);// 这里应该是手动断开，案例应该是只保证连接一个客户端，所以连接完以后，关闭了服务端socket
//                try {//                    mmServerSocket.close();
//                    mHandler.sendEmptyMessage(Constant.MSG_FINISH_LISTENING);
//                } catch (IOException e) {//                    e.printStackTrace();
//                }}}}/*** 管理连接的客户端socket* @param socket*/private void manageConnectSocket(BluetoothSocket socket) {// 只支持同时处理一个连接// mConnectedThread不为空,踢掉之前的客户端if(mConnectedThread != null) {mConnectedThread.cancle();}// 主线程更新UI,连接到了一个客户端mHandler.sendEmptyMessage(Constant.MSG_GOT_A_CLINET);// 新建一个线程,处理客户端发来的数据mConnectedThread = new ConnectedThread(socket, mHandler);mConnectedThread.start();}/*** 断开服务端，结束监听*/public void cancle() {try {mmServerSocket.close();mHandler.sendEmptyMessage(Constant.MSG_FINISH_LISTENING);} catch (IOException e) {e.printStackTrace();}}/*** 发送数据* @param data*/public void sendData(byte[] data){if(mConnectedThread != null) {mConnectedThread.write(data);}}
}

六、共同通讯处理类

public class ConnectedThread extends Thread{/** 当前连接的客户端BluetoothSocket*/private final BluetoothSocket mmSokcet;/** 读取数据流*/private final InputStream mmInputStream;/** 发送数据流*/private final OutputStream mmOutputStream;/** 与主线程通信Handler*/private Handler mHandler;private String TAG = "ConnectedThread";public ConnectedThread(BluetoothSocket socket,Handler handler) {mmSokcet = socket;mHandler = handler;InputStream tmpIn = null;OutputStream tmpOut = null;try {tmpIn = socket.getInputStream();tmpOut = socket.getOutputStream();} catch (IOException e) {e.printStackTrace();}mmInputStream = tmpIn;mmOutputStream = tmpOut;}@Overridepublic void run() {super.run();byte[] buffer = new byte[1024];while (true) {try {// 读取数据int bytes = mmInputStream.read(buffer);if(bytes > 0) {String data = new String(buffer,0,bytes,"utf-8");// 把数据发送到主线程, 此处还可以用广播Message message = mHandler.obtainMessage(Constant.MSG_GOT_DATA,data);mHandler.sendMessage(message);}Log.d(TAG, "messge size :" + bytes);} catch (IOException e) {e.printStackTrace();}}}// 踢掉当前客户端public void cancle() {try {mmSokcet.close();} catch (IOException e) {e.printStackTrace();}}/*** 服务端发送数据* @param data*/public void write(byte[] data) {try {mmOutputStream.write(data);} catch (IOException e) {e.printStackTrace();}}
}

七、基于安卓蓝牙通信的DEMO应用

7.1 DEMO运行截图

7.2 代码仓库

作业六代码仓库

7.3 核心代码

package com.example.bluetoothdemo;import android.Manifest;
import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Build;
import android.os.Handler;
import android.os.Message;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.sql.SQLOutput;
import java.util.UUID;public class MainActivity extends AppCompatActivity implements View.OnClickListener {public static final int REQUEST_BT_ENABLE_CODE = 200;public static final String BT_UUID = "00001101-0000-1000-8000-00805F9B34FB";//uuidprivate BluetoothAdapter mBluetoothAdapter;//蓝牙适配器private BlueToothStateReceiver mReceiver;//广播接收器private ConnectThread mConnectThread; //客户端线程private AcceptThread mAcceptThread; //服务端线程private RvAdapter mRvAdapter;@SuppressLint("StaticFieldLeak")private static MsgAdapter mMessageAdapter;private EditText inputEt;@SuppressLint("HandlerLeak")private static final Handler mHandler = new Handler() {@Overridepublic void dispatchMessage(Message msg) {mMessageAdapter.addMessage((String) msg.obj);}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//这是我是为了6.0以上的设备能搜索到结果，动态申请了位置权限。但是没有处理结果，因为我测试肯定点同意~- -requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 1001);initUI();registerRec();}private void initUI() {findViewById(R.id.open).setOnClickListener(this);findViewById(R.id.close).setOnClickListener(this);findViewById(R.id.start).setOnClickListener(this);findViewById(R.id.stop).setOnClickListener(this);findViewById(R.id.send).setOnClickListener(this);inputEt = (EditText) findViewById(R.id.input);RecyclerView mRecyclerView = (RecyclerView) findViewById(R.id.devices);mRecyclerView.setLayoutManager(new LinearLayoutManager(this));mRvAdapter = new RvAdapter(this);mRecyclerView.setAdapter(mRvAdapter);mRvAdapter.setOnItemClickListener(new RvAdapter.OnItemClickListener() {@Overridepublic void onClick(BluetoothDevice device) {mConnectThread = new ConnectThread(device);mConnectThread.start();}});RecyclerView mMessageView = (RecyclerView) findViewById(R.id.msglist);mMessageView.setLayoutManager(new LinearLayoutManager(this));mMessageAdapter = new MsgAdapter(this);mMessageView.setAdapter(mMessageAdapter);}private void openBT() {if (mBluetoothAdapter == null) {mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();}//1.设备不支持蓝牙，结束应用if (mBluetoothAdapter == null) {finish();return;}//2.判断蓝牙是否打开try {if (!mBluetoothAdapter.enable()) {//没打开请求打开Intent btEnable = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);startActivityForResult(btEnable, REQUEST_BT_ENABLE_CODE);}}catch (Exception EX) {System.out.println("异常");}}private void registerRec() {//3.注册蓝牙广播mReceiver = new BlueToothStateReceiver();IntentFilter filter = new IntentFilter();filter.addAction(BluetoothDevice.ACTION_FOUND);//搜多到蓝牙filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);//搜索结束registerReceiver(mReceiver, filter);}@Overrideprotected void onDestroy() {if (mReceiver != null) {unregisterReceiver(mReceiver);}super.onDestroy();}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {if (requestCode == REQUEST_BT_ENABLE_CODE) {if (resultCode == RESULT_OK) {//用户允许打开蓝牙mMessageAdapter.addMessage("用户同意打开蓝牙");} else if (resultCode == RESULT_CANCELED) {//用户取消打开蓝牙mMessageAdapter.addMessage("用户拒绝打开蓝牙");}}super.onActivityResult(requestCode, resultCode, data);}@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.open:openBT();mMessageAdapter.addMessage("打开蓝牙");if (mAcceptThread == null && mBluetoothAdapter != null) {mAcceptThread = new AcceptThread();mAcceptThread.start();mMessageAdapter.addMessage("启动服务线程");}break;case R.id.close:mBluetoothAdapter.disable();break;case R.id.start:if (mBluetoothAdapter != null) {mRvAdapter.clearDevices();//开始搜索前清空上一次的列表mBluetoothAdapter.startDiscovery();mMessageAdapter.addMessage("开始搜索蓝牙");} else {openBT();if (mBluetoothAdapter != null) {mRvAdapter.clearDevices();//开始搜索前清空上一次的列表mBluetoothAdapter.startDiscovery();mMessageAdapter.addMessage("开始搜索蓝牙");}}break;case R.id.stop:if (mBluetoothAdapter != null && mBluetoothAdapter.isDiscovering()) {mBluetoothAdapter.cancelDiscovery();}break;case R.id.send:String msg = inputEt.getText().toString();if (TextUtils.isEmpty(msg)) {Toast.makeText(this, "消息为空", Toast.LENGTH_SHORT).show();return;}if (mConnectThread != null) {//证明我主动去链接别人了mConnectThread.write(msg);} else if (mAcceptThread != null) {mAcceptThread.write(msg);}mMessageAdapter.addMessage("发送消息：" + msg);break;}}class BlueToothStateReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {Toast.makeText(MainActivity.this, "触发广播", Toast.LENGTH_SHORT).show();String action = intent.getAction();switch (action) {case BluetoothDevice.ACTION_FOUND:BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);Toast.makeText(MainActivity.this, "找到设备" + device.getName(), Toast.LENGTH_SHORT).show();if (mRvAdapter != null) {mRvAdapter.addDevice(device);}break;case BluetoothAdapter.ACTION_DISCOVERY_FINISHED:mMessageAdapter.addMessage("搜索结束");break;}}}class ConnectThread extends Thread {private BluetoothDevice mDevice;private BluetoothSocket mSocket;private InputStream btIs;private OutputStream btOs;private boolean canRecv;private PrintWriter writer;public ConnectThread(BluetoothDevice device) {mDevice = device;canRecv = true;}@Overridepublic void run() {if (mDevice != null) {try {//获取套接字BluetoothSocket temp = mDevice.createInsecureRfcommSocketToServiceRecord(UUID.fromString(BT_UUID));//mDevice.createRfcommSocketToServiceRecord(UUID.fromString(BT_UUID));//sdk 2.3以下使用mSocket = temp;//发起连接请求if (mSocket != null) {mSocket.connect();}sendHandlerMsg("连接 " + mDevice.getName() + "成功！");//获取输入输出流btIs = mSocket.getInputStream();btOs = mSocket.getOutputStream();//通讯-接收消息BufferedReader reader = new BufferedReader(new InputStreamReader(btIs, "UTF-8"));String content = null;while (canRecv) {content = reader.readLine();sendHandlerMsg("收到消息：" + content);}} catch (IOException e) {e.printStackTrace();sendHandlerMsg("错误：" + e.getMessage());} finally {try {if (mSocket != null) {mSocket.close();}//btIs.close();//两个输出流都依赖socket，关闭socket即可//btOs.close();} catch (IOException e) {e.printStackTrace();sendHandlerMsg("错误：" + e.getMessage());}}}}private void sendHandlerMsg(String content) {Message msg = mHandler.obtainMessage();msg.what = 1001;msg.obj = content;mHandler.sendMessage(msg);}public void write(String msg) {if (btOs != null) {try {if (writer == null) {writer = new PrintWriter(new OutputStreamWriter(btOs, "UTF-8"), true);}writer.println(msg);} catch (UnsupportedEncodingException e) {e.printStackTrace();writer.close();sendHandlerMsg("错误：" + e.getMessage());}}}}class AcceptThread extends Thread {private BluetoothServerSocket mServerSocket;private BluetoothSocket mSocket;private InputStream btIs;private OutputStream btOs;private PrintWriter writer;private boolean canAccept;private boolean canRecv;public AcceptThread() {canAccept = true;canRecv = true;}@Overridepublic void run() {try {//获取套接字try {BluetoothServerSocket temp = mBluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord("TEST", UUID.fromString(BT_UUID));mServerSocket = temp;}catch (Exception exception) {System.out.println("异常");}//监听连接请求 -- 作为测试，只允许连接一个设备if (mServerSocket != null) {// while (canAccept) {mSocket = mServerSocket.accept();sendHandlerMsg("有客户端连接");// }}//获取输入输出流btIs = mSocket.getInputStream();btOs = mSocket.getOutputStream();//通讯-接收消息BufferedReader reader = new BufferedReader(new InputStreamReader(btIs, "UTF-8"));String content = null;while (canRecv) {content = reader.readLine();sendHandlerMsg("收到消息：" + content);}} catch (IOException e) {e.printStackTrace();} finally {try {if (mSocket != null) {mSocket.close();}// btIs.close();//两个输出流都依赖socket，关闭socket即可// btOs.close();} catch (IOException e) {e.printStackTrace();sendHandlerMsg("错误：" + e.getMessage());}}}private void sendHandlerMsg(String content) {Message msg = mHandler.obtainMessage();msg.what = 1001;msg.obj = content;mHandler.sendMessage(msg);}public void write(String msg) {if (btOs != null) {try {if (writer == null) {writer = new PrintWriter(new OutputStreamWriter(btOs, "UTF-8"), true);}writer.println(msg);} catch (UnsupportedEncodingException e) {e.printStackTrace();writer.close();sendHandlerMsg("错误：" + e.getMessage());}}}}
}