蓝牙概述
蓝牙,是一种支持设备短距离通信(一般10m内)的无线电技术,能在包括移动电话、PDA、无线耳机、笔记本电脑、相关外设等众多设备之间,通过蓝牙设备之间的无线通信实现数据传输,实现数据传输,音频传输,文件传输,图片传输等多种应用的无线信息交换。利用“蓝牙”技术,能够有效地简化移动通信终端设备之间的通信,也能够成功地简化设备与因特网Internet之间的通信,从而数据传输变得更加迅速高效,为无线通信拓宽道路。蓝牙技术是一种无线数据和语音通信开放的全球规范,它是基于低成本的近距离无线连接,为固定和移动设备建立通信环境的一种特殊的近距离无线技术连接。目前,越来越多的企业采用蓝牙交互技术来实现自己的产品。
Java实现蓝牙交互的优势
Java是世界上最流行的编程语言之一。Java具有平台无关性、对象化编程、简单易用、可扩展性等特点,因此目前已广泛应用于企业和互联网领域。Java还提供了很好的蓝牙接口,可以帮助企业快速开发蓝牙交互应用。Java的蓝牙接口是基于JSR-82标准实现的,这个标准允许JAVA应用程序访问蓝牙网络的API。与其他大多数蓝牙接口不同,JSR-82可以在任意实现了JSR-82标准的蓝牙设备间进行通讯,这就保证了兼容性和灵活性。
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。
配对完成后,从端蓝牙设备会记录主端设备的信任信息,此时主端即可向从端设备发起呼叫,已配对的设备在下次呼叫时,不再需要重新配对。
Java蓝牙交互应用实例
导包
<dependency><groupId>net.sf.bluecove</groupId><artifactId>bluecove</artifactId><version>2.1.0</version>
</dependency>
BluetoothServer
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;//线程池private final static ExecutorService service = Executors.newCachedThreadPool();public String serverName;public String serverUUID;private OnServerListener mServerListener;public interface OnServerListener {void onConnected(InputStream inputStream, OutputStream outputStream);void onDisconnected();void onClose();}public BluetoothServer(String serverUUID, String serverName) {this.serverUUID = serverUUID;this.serverName = serverName;}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 ";name="+serverName;*/String url = "btspp://localhost:" + serverUUID;notifier = (StreamConnectionNotifier) Connector.open(url);service.submit(this);} catch (IOException e) {System.out.println(e.getMessage());;}}public OnServerListener getServerListener() {return mServerListener;}public void setServerListener(OnServerListener mServerListener) {this.mServerListener = mServerListener;}@Overridepublic void run() {try {//阻塞的,等待设备连接streamConnection = notifier.acceptAndOpen(); inputStream = streamConnection.openInputStream();outputStream = streamConnection.openOutputStream();if (mServerListener != null) {mServerListener.onConnected(inputStream, outputStream);}} catch (IOException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();} finally {}}
}
BluetoothClient
public class BluetoothClient {private StreamConnection streamConnection;private OnDiscoverListener onDiscoverListener = null;private OnClientListener onClientListener = null;public interface OnClientListener {void onConnected(InputStream inputStream, OutputStream outputStream);void onConnectionFailed();void onDisconnected();void onClose();}public interface OnDiscoverListener {void onDiscover(RemoteDevice remoteDevice);}public BluetoothClient() {}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;}public void find() throws IOException, InterruptedException {//附近所有的蓝牙设备,必须先执行 runDiscoverySet<RemoteDevice> devicesDiscovered = RemoteDeviceDiscovery.getDevices(); Iterator<RemoteDevice> itr = devicesDiscovered.iterator();//连接while (itr.hasNext()) { RemoteDevice remoteDevice = itr.next();onDiscoverListener.onDiscover(remoteDevice);}}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());}}
}
RemoteDeviceDiscovery
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();private static DiscoveryListener listener = new DiscoveryListener() {public void inquiryCompleted(int discType) {System.out.println("#" + "搜索完成");synchronized (inquiryCompletedEvent) {inquiryCompletedEvent.notifyAll();}}@Overridepublic 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();}}@Overridepublic 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");}@Overridepublic void serviceSearchCompleted(int arg0, int arg1) {System.out.println("#" + "serviceSearchCompleted");synchronized(serviceSearchCompletedEvent){serviceSearchCompletedEvent.notifyAll();}}};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());}}}public static Set<RemoteDevice> getDevices() throws IOException, InterruptedException {findDevices();return devicesDiscovered;}public static String searchService(RemoteDevice btDevice, String serviceUUID) throws IOException, InterruptedException {UUID[] searchUuidSet = new UUID[] { new UUID(serviceUUID, false) };int[] attrIDs = new int[] {// Service name0x0100 };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 "";}}
}
测试
Bluetooth Server
@Test
public void test(){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() {@Overridepublic void onConnected(InputStream inputStream, OutputStream outputStream) {System.out.printf("Connected");//添加通信代码}@Overridepublic void onDisconnected() {}@Overridepublic void onClose() {}});server.start();
}
测试结果
Connected to the target VM, address: '127.0.0.1:8442', transport: 'socket'
Native Library intelbth_x64 not available
Native Library bluecove_x64 not available
BlueCove libraries not available
Disconnected from the target VM, address: '127.0.0.1:8442', transport: 'socket'
没有找到_64的包。
看看导包的版本
下载_64版本
官网:BlueCove - BlueCove JSR-82 project
下载地址:https://sourceforge.net/projects/bluecove/files/
ps:下面自己测试吧。
JNI,Java Native Interface,主要是通过读取其他底层语言的文件,转换成Java的类,操作设备。
另外还有连接打印机、pos机等,也是使用Java的JNI调用其他底层语言的文件,如打印机使用jacob读取dll文件、可实现无接触操作语音智能打印等。