PC端实现蓝牙开发

蓝牙作为一种短距离无线通讯技术，越来越融合到我们的生活当中，软件开发也是随处可见。本文介绍的是PC端与其他蓝牙设备建立通讯的一个案例。

　　蓝牙客户端，即是请求连接的一端，搜索会发现可连接的蓝牙设备名称。

　　蓝牙服务端，提供服务的一端。往往生活中使用到的蓝牙（比如手机是个双重角色），又是客户端又是服务端。

蓝牙通信的原理

　　蓝牙技术规定每一对设备之间进行蓝牙通讯时，必须一个为主角色，另一为从角色，才能进行通信，通信时，必须由主端进行查找，发起配对，建链成功后，双方即可收发数据。蓝牙主端设备发起呼叫，首先是查找，找出周围处于可被查找的蓝牙设备。主端设备找到从端蓝牙设备后，与从端蓝牙设备进行配对，此时需要输入从端设备的PIN码，也有设备不需要输入PIN码。

蓝牙流程

蓝牙客户端Socket的与Sokcet流程是一样的，只不过参数不同而已。如下：
1、创建客户端蓝牙Sokcet
2、创建连接
3、读写数据
4、关闭

因此又可以视为一个短连接。

一、jar包

首先，在PC端实现蓝牙java并没有提供官方jar包，本文使用的是一个第三方库。需要手动导入到maven仓库，

不会导仓库的请参考https://www.cnblogs.com/zeussbook/p/9930679.htm。

第三方jar包下载地址：https://sourceforge.net/projects/bluecove/files/BlueCove/2.1.0/bluecove-2.1.0.jar/download

二、代码部分

2.1蓝牙服务端

package com.shunyutong.test.bluetooth;

import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.LocalDevice;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
import javax.microedition.io.StreamConnectionNotifier;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @Auther: lanhaifeng
 * @Date: 2020/5/4 0004 16:28
 * @Description: 蓝牙服务端
 * @statement:
 */
public class BluetoothServer implements Runnable{

    //本机蓝牙设备
    private LocalDevice local = null;
    // 流连接
    private StreamConnection streamConnection = null;

    // 输入流
    private InputStream inputStream;
    private OutputStream outputStream;
    //接入通知
    private StreamConnectionNotifier notifier;
    //基于缓存的线程池
    private final static ExecutorService service = Executors.newCachedThreadPool();

    public String serverName;
    public String serverUUID;

    private OnServerListener mServerListener;

    /**
     * 服务监听接口
     */
    public interface OnServerListener {
        void onConnected(InputStream inputStream, OutputStream outputStream);
        void onDisconnected();
        void onClose();
    }

    /**
     * 蓝牙服务有参构造函数
     * @param serverUUID id
     * @param serverName 名称
     */
    public BluetoothServer(String serverUUID, String serverName) {
        this.serverUUID = serverUUID;
        this.serverName = serverName;
    }

    /**
     * 启动
     */
    public void start() {
        try {
            local = LocalDevice.getLocalDevice();
            if (!local.setDiscoverable(DiscoveryAgent.GIAC))
                System.out.println("请将蓝牙设置为可被发现");
            //作为服务端，被请求
            String url = "btspp://localhost:" +  serverUUID+ ";name="+serverName;
            notifier = (StreamConnectionNotifier) Connector.open(url);

            service.submit(this);
        } catch (IOException e) {
            System.out.println(e.getMessage());;
        }
    }


    /**
     * 重写run（）
     */
    @Override
    public void run() {
        try {
            streamConnection = notifier.acceptAndOpen();                //阻塞的，等待设备连接
            inputStream = streamConnection.openInputStream();
            outputStream = streamConnection.openOutputStream();

            if (mServerListener != null) {
                mServerListener.onConnected(inputStream, outputStream);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
        }
    }


    public OnServerListener getServerListener() {
        return mServerListener;
    }

    public void setServerListener(OnServerListener mServerListener) {
        this.mServerListener = mServerListener;
    }
}

2.2蓝牙客户端

package com.shunyutong.test.bluetooth;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Set;
import javax.bluetooth.RemoteDevice;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
/**
 * @Auther: lanhaifeng
 * @Date: 2020/5/4 0004 15:37
 * @Description:蓝牙客户端类
 * @statement:
 */
public class BluetoothClient {
    private StreamConnection streamConnection;//流连接
    private OnDiscoverListener onDiscoverListener = null;//发现监听
    private OnClientListener onClientListener = null;//客户端监听

    /**
     * 客户端监听
     */
    public interface OnClientListener {
        void onConnected(InputStream inputStream, OutputStream outputStream);
        void onConnectionFailed();
        void onDisconnected();
        void onClose();
    }

    /**
     * 发现监听
     */
    public interface OnDiscoverListener {
        void onDiscover(RemoteDevice remoteDevice);
    }


    /**
     * 无参构造函数
     */
    public BluetoothClient() {
    }

    /**
     * 查找所有
     * @throws IOException
     * @throws InterruptedException
     */
    public void find() throws IOException, InterruptedException {
        //附近所有的蓝牙设备，必须先执行 runDiscovery
        Set<RemoteDevice> devicesDiscovered = RemoteDeviceDiscovery.getDevices();
        Iterator<RemoteDevice> itr = devicesDiscovered.iterator();
        //连接
        while (itr.hasNext()) {
            RemoteDevice remoteDevice = itr.next();

            onDiscoverListener.onDiscover(remoteDevice);
        }
    }

    /**
     * 启动连接
     * @param remoteDevice
     * @param serviceUUID
     * @throws IOException
     * @throws InterruptedException
     */
    public void startClient(RemoteDevice remoteDevice, String serviceUUID) throws IOException, InterruptedException {
        String url = RemoteDeviceDiscovery.searchService(remoteDevice, serviceUUID);

        streamConnection = (StreamConnection) Connector.open(url);
        if (this.onClientListener != null) {
            this.onClientListener.onConnected(streamConnection.openInputStream(), streamConnection.openOutputStream());
        }
    }

    public OnDiscoverListener getOnDiscoverListener() {
        return onDiscoverListener;
    }


    public void setOnDiscoverListener(OnDiscoverListener onDiscoverListener) {
        this.onDiscoverListener = onDiscoverListener;
    }


    public OnClientListener getClientListener() {
        return onClientListener;
    }


    public void setClientListener(OnClientListener onClientListener) {
        this.onClientListener = onClientListener;
    }


}

2.3设备查找类

package com.shunyutong.test.bluetooth;

import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import java.util.Vector;

import javax.bluetooth.DataElement;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.UUID;
/**
 * @Auther: lanhaifeng
 * @Date: 2020/5/4 0004 16:07
 * @Description:设备查找类
 * @statement:
 */
public class RemoteDeviceDiscovery {

    public final static Set<RemoteDevice> devicesDiscovered = new HashSet<RemoteDevice>();

    public final static Vector<String> serviceFound = new Vector<String>();

    final static Object serviceSearchCompletedEvent = new Object();
    final static Object inquiryCompletedEvent = new Object();


    /**
     * 发现监听
     */
    private static DiscoveryListener listener = new DiscoveryListener() {
        public void inquiryCompleted(int discType) {
            System.out.println("#" + "搜索完成");
            synchronized (inquiryCompletedEvent) {
                inquiryCompletedEvent.notifyAll();
            }
        }

        /**
         * 发现设备
         * @param remoteDevice
         * @param deviceClass
         */
        @Override
        public void deviceDiscovered(RemoteDevice remoteDevice, DeviceClass deviceClass) {
            devicesDiscovered.add(remoteDevice);

            try {
                System.out.println("#发现设备" + remoteDevice.getFriendlyName(false));
            } catch (IOException e) {
                e.printStackTrace();
            }

        }

        /**
         * 发现服务
         * @param transID id
         * @param servRecord 服务记录
         */
        @Override
        public void servicesDiscovered(int transID, ServiceRecord[] servRecord) {
            for (int i = 0; i < servRecord.length; i++) {
                String url = servRecord[i].getConnectionURL(ServiceRecord.NOAUTHENTICATE_NOENCRYPT, false);
                if (url == null) {
                    continue;
                }
                serviceFound.add(url);
                DataElement serviceName = servRecord[i].getAttributeValue(0x0100);
                if (serviceName != null) {
                    System.out.println("service " + serviceName.getValue() + " found " + url);
                } else {
                    System.out.println("service found " + url);
                }
            }
            System.out.println("#" + "servicesDiscovered");
        }

        /**
         * 服务搜索已完成
         * @param arg0
         * @param arg1
         */
        @Override
        public void serviceSearchCompleted(int arg0, int arg1) {
            System.out.println("#" + "serviceSearchCompleted");
            synchronized(serviceSearchCompletedEvent){
                serviceSearchCompletedEvent.notifyAll();
            }
        }
    };


    /**
     * 查找设备
     * @throws IOException
     * @throws InterruptedException
     */
    private static void findDevices() throws IOException, InterruptedException {

        devicesDiscovered.clear();

        synchronized (inquiryCompletedEvent) {

            LocalDevice ld = LocalDevice.getLocalDevice();

            System.out.println("#本机蓝牙名称:" + ld.getFriendlyName());

            boolean started = LocalDevice.getLocalDevice().getDiscoveryAgent().startInquiry(DiscoveryAgent.GIAC,listener);

            if (started) {
                System.out.println("#" + "等待搜索完成...");
                inquiryCompletedEvent.wait();
                LocalDevice.getLocalDevice().getDiscoveryAgent().cancelInquiry(listener);
                System.out.println("#发现设备数量：" + devicesDiscovered.size());
            }
        }
    }

    /**
     * 获取设备
     * @return
     * @throws IOException
     * @throws InterruptedException
     */
    public static Set<RemoteDevice> getDevices() throws IOException, InterruptedException {
        findDevices();
        return devicesDiscovered;
    }

    /**
     * 查找服务
     * @param btDevice
     * @param serviceUUID
     * @return
     * @throws IOException
     * @throws InterruptedException
     */
    public static String searchService(RemoteDevice btDevice, String serviceUUID) throws IOException, InterruptedException {
        UUID[] searchUuidSet = new UUID[] { new UUID(serviceUUID, false) };

        int[] attrIDs =  new int[] {
                0x0100 // Service name
        };

        synchronized(serviceSearchCompletedEvent) {
            System.out.println("search services on " + btDevice.getBluetoothAddress() + " " + btDevice.getFriendlyName(false));
            LocalDevice.getLocalDevice().getDiscoveryAgent().searchServices(attrIDs, searchUuidSet, btDevice, listener);
            serviceSearchCompletedEvent.wait();
        }

        if (serviceFound.size() > 0) {
            return serviceFound.elementAt(0);
        } else {
            return "";
        }
    }
}

2.4蓝牙服务端使用

package com.shunyutong.test.bluetoothService;

import com.shunyutong.test.bluetooth.BluetoothServer;

import java.io.InputStream;
import java.io.OutputStream;

/**
 * @Auther: lanhaifeng
 * @Date: 2020/5/4 0004 16:47
 * @Description: 蓝牙服务端通信业务
 * @statement:
 */
public class BluetoothServerService {

    public static void main(String[] argv) {
        final String serverName = "Bluetooth Server Test";
        final String serverUUID = "1000110100001000800000805F9B34FB";  //根据需要自定义

        BluetoothServer server = new BluetoothServer(serverUUID, serverName);
        server.setServerListener(new BluetoothServer.OnServerListener() {

            @Override
            public void onConnected(InputStream inputStream, OutputStream outputStream) {
                System.out.printf("Connected");
                //添加通信代码
                System.out.println(server.serverName);
                System.out.println(server.serverUUID);

            }

            @Override
            public void onDisconnected() {

            }

            @Override
            public void onClose() {

            }

        });

        server.start();
    }
}

2.5蓝牙客户端使用

package com.shunyutong.test.bluetoothService;

import com.shunyutong.test.bluetooth.BluetoothClient;

import javax.bluetooth.RemoteDevice;
import javax.microedition.io.ConnectionNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Vector;

/**
 * @Auther: lanhaifeng
 * @Date: 2020/5/4 0004 16:51
 * @Description: 蓝牙客户端业务类
 * @statement:
 */
public class BluetoothClientService {

    public static void main(String[] argv) {

        final String serverUUID = "1000110100001000800000805F9B34FB"; //需要与服务端相同

        BluetoothClient client = new BluetoothClient();

        Vector<RemoteDevice> remoteDevices = new Vector<>();

        client.setOnDiscoverListener(new BluetoothClient.OnDiscoverListener() {

            @Override
            public void onDiscover(RemoteDevice remoteDevice) {
                remoteDevices.add(remoteDevice);
            }

        });

        client.setClientListener(new BluetoothClient.OnClientListener() {

            @Override
            public void onConnected(InputStream inputStream, OutputStream outputStream) {
                System.out.printf("Connected");
                //添加通信代码

            }

            @Override
            public void onConnectionFailed() {
                System.out.printf("Connection failed");
            }

            @Override
            public void onDisconnected() {

            }

            @Override
            public void onClose() {

            }

        });

        try {
            client.find();

            if (remoteDevices.size() > 0 ) {

                client.startClient(remoteDevices.firstElement(), serverUUID);
            }
        }catch (InterruptedException e) {
            e.printStackTrace();
        }catch (ConnectionNotFoundException e){
            System.out.println("当前蓝牙不在线");
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}

测试效果