J2ME蓝牙程序开发实战入门
2008-01-05 20:35:06 来源:WEB开发网核心提示:概述目前,很多手机已经具备了蓝牙功能,J2ME蓝牙程序开发实战入门,虽然MIDP2.0没有包括蓝牙API,但是JCP定义了JSR82, java APIs for Bluetooth Wireless Technology (JABWT).这是一个可选API,很多支持MIDP2.0的手机已经实现了,比如Nokia 66
概述 目前,很多手机已经具备了蓝牙功能。虽然MIDP2.0没有包括蓝牙API,但是JCP定义了JSR82, java APIs for Bluetooth Wireless Technology (JABWT).这是一个可选API,很多支持MIDP2.0的手机已经实现了,比如Nokia 6600, Nokia 6670,Nokia7610等等。对于一个开发者来说,假如目标平台支持JSR82的话,在制作联网对战类型游戏或者应用的时候,蓝牙是一个相当不错的选择。本文给出了一个最简单的蓝牙应用的J2ME程序,用以帮助开发者快速的把握JSR82。该程序分别在2台蓝牙设备上安装后,一台设备作为服务端先运行,一台设备作为客户端后运行。在服务端上我们发布了一个服务,该服务的功能是把客户端发过来的字符串转变为大写字符串。客户端起动并搜索到服务端的服务后,我们就可以从客户端的输入框里输入任意的字符串,发送到服务端去,同时观察服务端的反馈结果。
本文并不具体讲述蓝牙的运行机制和JSR82的API结构,关于这些知识点,请参考本文的参考资料一节,这些参考资料会给你一个权威的精确的解释。
该程序包括3个java文件。一个是MIDlet,另外2个为服务端GUI和客户端GUI。该程序已经在wtk22模拟器和Nokia 6600,Nokia 6670两款手机上测试通过。
本文并不具体讲述蓝牙的运行机制和JSR82的API结构,关于这些知识点,请参考本文的参考资料一节,这些参考资料会给你一个权威的精确的解释。
实例代码
该程序包括3个java文件。一个是MIDlet,另外2个为服务端GUI和客户端GUI。该程序已经在wtk22模拟器和Nokia 6600,Nokia 6670两款手机上测试通过。
StupidBTMIDlet.java
- import javax.microedition.lcdui.Alert;
- import javax.microedition.lcdui.AlertType;
- import javax.microedition.lcdui.Command;
- import javax.microedition.lcdui.CommandListener;
- import javax.microedition.lcdui.Display;
- import javax.microedition.lcdui.Displayable;
- import javax.microedition.lcdui.List;
- import javax.microedition.midlet.MIDlet;
- import javax.microedition.midlet.MIDletStateChangeException;
- /**
- * @author Jagie
- *
- * MIDlet
- */
- public class StupidBTMIDlet extends MIDlet implements CommandListener {
- List list;
- ServerBox sb;
- ClientBox cb;
- /*
- * (non-Javadoc)
- *
- * @see javax.microedition.midlet.MIDlet#startApp()
- */
- PRotected void startApp() throws MIDletStateChangeException {
- list = new List("傻瓜蓝牙入门", List.IMPLICIT);
- list.append("Client", null);
- list.append("Server", null);
- list.setCommandListener(this);
- Display.getDisplay(this).setCurrent(list);
- }
- /**
- * debug方法
- * @param s 要显示的字串
- */
- public void showString(String s) {
- Displayable dp = Display.getDisplay(this).getCurrent();
- Alert al = new Alert(null, s, null, AlertType.INFO);
- al.setTimeout(2000);
- Display.getDisplay(this).setCurrent(al, dp);
- }
- /**
- * 显示主菜单
- *
- */
- public void showMainMenu() {
- Display.getDisplay(this).setCurrent(list);
- }
- protected void pauseApp() {
- // TODO Auto-generated method stub
- }
- public void commandAction(Command com, Displayable disp) {
- if (com == List.SELECT_COMMAND) {
- List list = (List) disp;
- int index = list.getSelectedIndex();
- if (index == 1) {
- if (sb == null) {
- sb = new ServerBox(this);
- }
- sb.setString(null);
- Display.getDisplay(this).setCurrent(sb);
- } else {
- //每次都生成新的客户端实例
- cb = null;
- System.gc();
- cb = new ClientBox(this);
- Display.getDisplay(this).setCurrent(cb);
- }
- }
- }
- protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
- // TODO Auto-generated method stub
- }
- }
ClientBox.java
- import java.io.DataInputStream;
- import java.io.DataOutputStream;
- import java.io.IOException;
- import java.util.Vector;
- import javax.microedition.io.Connector;
- import javax.microedition.io.StreamConnection;
- import javax.microedition.lcdui.Command;
- import javax.microedition.lcdui.CommandListener;
- import javax.microedition.lcdui.Displayable;
- import javax.microedition.lcdui.Form;
- import javax.microedition.lcdui.Gauge;
- import javax.microedition.lcdui.StringItem;
- import javax.microedition.lcdui.TextField;
- //jsr082 API
- import javax.bluetooth.BluetoothStateException;
- 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;
- /**
- * 客户端GUI
- * @author Jagie
- *
- * TODO To change the template for this generated type comment go to
- * Window - Preferences - Java - Code Style - Code Templates
- */
- public class ClientBox extends Form implements Runnable, CommandListener,
- DiscoveryListener {
- //字串输入框
- TextField input = new TextField(null, "", 50, TextField.ANY);
- //loger
- StringItem result = new StringItem("结果:", "");
- private DiscoveryAgent discoveryAgent;
- private UUID[] uuidSet;
- //响应服务的UUID
- private static final UUID ECHO_SERVER_UUID = new UUID(
- "F0E0D0C0B0A000908070605040302010", false);
- //设备集合
- Vector devices = new Vector();
- //服务集合
- Vector records = new Vector();
- //服务搜索的事务id集合
- int[] transIDs;
- StupidBTMIDlet midlet;
- public ClientBox(StupidBTMIDlet midlet) {
- super("");
- this.midlet=midlet;
- this.append(result);
- this.addCommand(new Command("取消",Command.CANCEL,1));
- this.setCommandListener(this);
- new Thread(this).start();
- }
- public void commandAction(Command arg0, Displayable arg1) {
- if(arg0.getCommandType()==Command.CANCEL){
- midlet.showMainMenu();
- }else{
- //匿名内部Thread,访问远程服务。
- Thread fetchThread=new Thread(){
- public void run(){
- for(int i=0;i<records.size();i++){
- ServiceRecord sr=(ServiceRecord)records.elementAt(i);
- if(accessService(sr)){
- //访问到一个可用的服务即可
- break;
- }
- }
- }
- };
- fetchThread.start();
- }
- }
- private boolean accessService(ServiceRecord sr){
- boolean result=false;
- try {
- String url = sr.getConnectionURL(
- ServiceRecord.NOAUTHENTICATE_NOENCRYPT, false);
- StreamConnection conn = (StreamConnection) Connector.open(url);
- DataOutputStream dos=conn.openDataOutputStream();
- dos.writeUTF(input.getString());
- dos.close();
- DataInputStream dis=conn.openDataInputStream();
- String echo=dis.readUTF();
- dis.close();
- showInfo("反馈结果是:"+echo);
- result=true;
- } catch (IOException e) {
- }
- return result;
- }
- public synchronized void run() {
- //发现设备和服务的过程中,给用户以Gauge
- Gauge g=new Gauge(null,false,Gauge.INDEFINITE,Gauge.CONTINUOUS_RUNNING);
- this.append(g);
- showInfo("蓝牙初始化...");
- boolean isBTReady = false;
- try {
- LocalDevice localDevice = LocalDevice.getLocalDevice();
- discoveryAgent = localDevice.getDiscoveryAgent();
- isBTReady = true;
- } catch (Exception e) {
- e.printStackTrace();
- }
- if (!isBTReady) {
- showInfo("蓝牙不可用");
- //删除Gauge
- this.delete(1);
- return;
- }
- uuidSet = new UUID[2];
- //标志我们的响应服务的UUID集合
- uuidSet[0] = new UUID(0x1101);
- uuidSet[1] = ECHO_SERVER_UUID;
- try {
- discoveryAgent.startInquiry(DiscoveryAgent.GIAC, this);
- } catch (BluetoothStateException e) {
- }
- try {
- //阻塞,由inquiryCompleted()回调方法唤醒
- wait();
- } catch (InterruptedException e1) {
- e1.printStackTrace();
- }
- showInfo("设备搜索完毕,共找到"+devices.size()+"个设备,开始搜索服务");
- transIDs = new int[devices.size()];
- for (int i = 0; i < devices.size(); i++) {
- RemoteDevice rd = (RemoteDevice) devices.elementAt(i);
- try {
- //记录每一次服务搜索的事务id
- transIDs[i] = discoveryAgent.searchServices(null, uuidSet,
- rd, this);
- } catch (BluetoothStateException e) {
- continue;
- }
- }
- try {
- //阻塞,由serviceSearchCompleted()回调方法在所有设备都搜索完的情况下唤醒
- wait();
- } catch (InterruptedException e1) {
- e1.printStackTrace();
- }
- showInfo("服务搜索完毕,共找到"+records.size()+"个服务,预备发送请求");
- if(records.size()>0){
- this.append(input);
- this.addCommand(new Command("发送",Command.OK,0));
- }
- //删除Gauge
- this.delete(1);
- }
- /**
- * debug
- * @param s
- */
- private void showInfo(String s){
- StringBuffer sb=new StringBuffer(result.getText());
- if(sb.length()>0){
- sb.append("\n");
- }
- sb.append(s);
- result.setText(sb.toString());
- }
- /**
- * 回调方法
- */
- public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) {
- if (devices.indexOf(btDevice) == -1) {
- devices.addElement(btDevice);
- }
- }
- /**
- * 回调方法,唤醒初始化线程
- */
- public void inquiryCompleted(int discType) {
- synchronized (this) {
- notify();
- }
- }
- /**
- * 回调方法
- */
- public void servicesDiscovered(int transID, ServiceRecord[] servRecord) {
- for (int i = 0; i < servRecord.length; i++) {
- records.addElement(servRecord[i]);
- }
- }
- /**
- * 回调方法,唤醒初始化线程
- */
- public void serviceSearchCompleted(int transID, int respCode) {
- for (int i = 0; i < transIDs.length; i++) {
- if (transIDs[i] == transID) {
- transIDs[i] = -1;
- break;
- }
- }
- //假如所有的设备都已经搜索服务完毕,则唤醒初始化线程。
- boolean finished = true;
- for (int i = 0; i < transIDs.length; i++) {
- if (transIDs[i] != -1) {
- finished = false;
- break;
- }
- }
- if (finished) {
- synchronized (this) {
- notify();
- }
- }
- }
- }
ServerBox.java
- import java.io.DataInputStream;
- import java.io.DataOutputStream;
- import java.io.IOException;
- import java.util.Vector;
- import javax.bluetooth.DiscoveryAgent;
- import javax.bluetooth.LocalDevice;
- import javax.bluetooth.ServiceRecord;
- import javax.bluetooth.UUID;
- import javax.microedition.io.Connector;
- import javax.microedition.io.StreamConnection;
- import javax.microedition.io.StreamConnectionNotifier;
- import javax.microedition.lcdui.Command;
- import javax.microedition.lcdui.CommandListener;
- import javax.microedition.lcdui.Displayable;
- import javax.microedition.lcdui.TextBox;
- import javax.microedition.lcdui.TextField;
- /**
- * 服务端GUI
- * @author Jagie
- *
- * TODO To change the template for this generated type comment go to
- * Window - Preferences - Java - Code Style - Code Templates
- */
- public class ServerBox extends TextBox implements Runnable, CommandListener {
- Command com_pub = new Command("开启服务", Command.OK, 0);
- Command com_cancel = new Command("终止服务", Command.CANCEL, 0);
- Command com_back = new Command("返回", Command.BACK, 1);
- LocalDevice localDevice;
- StreamConnectionNotifier notifier;
- ServiceRecord record;
- boolean isClosed;
- ClientProcessor processor;
- StupidBTMIDlet midlet;
- //响应服务的uuid
- private static final UUID ECHO_SERVER_UUID = new UUID(
- "F0E0D0C0B0A000908070605040302010", false);
- public ServerBox(StupidBTMIDlet midlet) {
- super(null, "", 500, TextField.ANY);
- this.midlet = midlet;
- this.addCommand(com_pub);
- this.addCommand(com_back);
- this.setCommandListener(this);
- }
- public void run() {
- boolean isBTReady = false;
- try {
- localDevice = LocalDevice.getLocalDevice();
- if (!localDevice.setDiscoverable(DiscoveryAgent.GIAC)) {
- showInfo("无法设置设备发现模式");
- return;
- }
- // prepare a URL to create a notifier
- StringBuffer url = new StringBuffer("btspp://");
- // indicate this is a server
- url.append("localhost").append(':');
- // add the UUID to identify this service
- url.append(ECHO_SERVER_UUID.toString());
- // add the name for our service
- url.append(";name=Echo Server");
- // request all of the client not to be authorized
- // some devices fail on authorize=true
- url.append(";authorize=false");
- // create notifier now
- notifier = (StreamConnectionNotifier) Connector
- .open(url.toString());
- record = localDevice.getRecord(notifier);
- // remember we've reached this point.
- isBTReady = true;
- } catch (Exception e) {
- e.printStackTrace();
- }
- // nothing to do if no bluetooth available
- if (isBTReady) {
- showInfo("初始化成功,等待连接");
- this.removeCommand(com_pub);
- this.addCommand(com_cancel);
- }
else {
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