J2ME藍(lán)牙手機應(yīng)用程序開發(fā)實戰(zhàn)入門
發(fā)布時間：2005.05.30 11:17 來源：http://www.javaresearch.org 作者：Jagie
目前，很多手機已經(jīng)具備了藍(lán)牙功能。雖然MIDP2.0沒有包括藍(lán)牙API,但是JCP定義了JSR82, Java APIs for Bluetooth Wireless Technology (JABWT).這是一個可選API,很多支持MIDP2.0的手機已經(jīng)實現(xiàn)了，比如Nokia 6600, Nokia 6670，Nokia7610等等。對于一個開發(fā)者來說,如果目標(biāo)平臺支持JSR82的話，在制作聯(lián)網(wǎng)對戰(zhàn)類型游戲或者應(yīng)用的時候，藍(lán)牙是一個相當(dāng)不錯的選擇。
本文給出了一個最簡單的藍(lán)牙應(yīng)用的J2ME程序，用以幫助開發(fā)者快速的掌握J(rèn)SR82。該程序分別在2臺藍(lán)牙設(shè)備上安裝后，一臺設(shè)備作為服務(wù)端先運行，一臺設(shè)備作為客戶端后運行。在服務(wù)端上我們發(fā)布了一個服務(wù)，該服務(wù)的功能是把客戶端發(fā)過來的字符串轉(zhuǎn)變?yōu)榇髮懽址?。客戶端起動并搜索到服?wù)端的服務(wù)后，我們就可以從客戶端的輸入框里輸入任意的字符串，發(fā)送到服務(wù)端去，同時觀察服務(wù)端的反饋結(jié)果。
實例代碼
該程序包括3個java文件。一個是MIDlet,另外2個為服務(wù)端GUI和客戶端GUI。該程序已經(jīng)在wtk22模擬器和Nokia 6600,Nokia 6670兩款手機上測試通過。
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 ("藍(lán)牙入門", List.IMPLICIT); list.append("Client", null); list.append("Server", null); list.setCommandListener(this); Display.getDisplay(this).setCurrent(list); } /** * debug方法 * @param s 要顯示的字串 */ 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); } /** * 顯示主菜單 * */ 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 { //每次都生成新的客戶端實例 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; /** * 客戶端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 { //字串輸入框 TextField input = new TextField(null, "", 50, TextField.ANY); //loger StringItem result = new StringItem("結(jié)果:", ""); private DiscoveryAgent discoveryAgent; private UUID[] uuidSet; //響應(yīng)服務(wù)的UUID private static final UUID ECHO_SERVER_UUID = new UUID( "F0E0D0C0B0A000908070605040302010", false); //設(shè)備集合 Vector devices = new Vector(); //服務(wù)集合 Vector records = new Vector(); //服務(wù)搜索的事務(wù)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{ //匿名內(nèi)部Thread，訪問遠(yuǎn)程服務(wù)。 Thread fetchThread=new Thread() { public void run() { for(int i=0;i<records.size();i++) { ServiceRecord sr=(ServiceRecord) records.elementAt(i); if(accessService(sr)) { //訪問到一個可用的服務(wù)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("反饋結(jié)果是:"+echo); result=true; } catch (IOException e) { } return result; } public synchronized void run() { //發(fā)現(xiàn)設(shè)備和服務(wù)的過程中， 給用戶以Gauge Gauge g=new Gauge(null,false,Gauge.INDEFINITE, Gauge.CONTINUOUS_RUNNING); this.append(g); showInfo("藍(lán)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("藍(lán)牙不可用"); //刪除Gauge this.delete(1); return; } uuidSet = new UUID[2]; //標(biāo)志我們的響應(yīng)服務(wù)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()回調(diào)方法喚醒 wait(); } catch (InterruptedException e1) { e1.printStackTrace(); } showInfo("設(shè)備搜索完畢,共找到" +devices.size()+"個設(shè)備,開始搜索服務(wù)"); transIDs = new int[devices.size()]; for (int i = 0; i < devices.size(); i++) { RemoteDevice rd = (RemoteDevice) devices.elementAt(i); try { //記錄每一次服務(wù)搜索的事務(wù)id transIDs[i] = discoveryAgent.searchServices (null, uuidSet, rd, this); } catch (BluetoothStateException e) { continue; } } try { //阻塞,由serviceSearchCompleted() 回調(diào)方法在所有設(shè)備都搜索完的情況下喚醒 wait(); } catch (InterruptedException e1) { e1.printStackTrace(); } showInfo("服務(wù)搜索完畢, 共找到"+records.size()+ "個服務(wù),準(zhǔn)備發(fā)送請求"); if(records.size()>0){ this.append(input); this.addCommand(new Command ("發(fā)送",Command.OK,0)); } //刪除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()); } /** * 回調(diào)方法 */ public void deviceDiscovered (RemoteDevice btDevice, DeviceClass cod) { if (devices.indexOf(btDevice) == -1) { devices.addElement(btDevice); } } /** * 回調(diào)方法，喚醒初始化線程 */ public void inquiryCompleted(int discType) { synchronized (this) { notify(); } } /** * 回調(diào)方法 */ public void servicesDiscovered (int transID, ServiceRecord[] servRecord) { for (int i = 0; i < servRecord.length; i++) { records.addElement(servRecord[i]); } } /** * 回調(diào)方法，喚醒初始化線程 */ public void serviceSearchCompleted (int transID, int respCode) { for (int i = 0; i < transIDs.length; i++) { if (transIDs[i] == transID) { transIDs[i] = -1; break; } } //如果所有的設(shè)備都已經(jīng)搜索服務(wù)完畢， 則喚醒初始化線程。 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; /** * 服務(wù)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 ("開啟服務(wù)", Command.OK, 0); Command com_cancel = new Command ("終止服務(wù)", 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; //響應(yīng)服務(wù)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("無法設(shè)置設(shè)備發(fā)現(xiàn)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，等待連接"); this.removeCommand(com_pub); this.addCommand(com_cancel); } else { showInfo("初始化失敗,退出"); return; } // 生成服務(wù)端服務(wù)線程對象 processor = new ClientProcessor(); // ok, start accepting connections then while (!isClosed) { StreamConnection conn = null; try { conn = notifier.acceptAndOpen(); } catch (IOException e) { // wrong client or interrupted - continue anyway continue; } processor.addConnection(conn); } } public void publish() { isClosed = false; this.setString(null); new Thread(this).start(); } public void cancelService() { isClosed = true; showInfo("服務(wù)終止"); this.removeCommand(com_cancel); this.addCommand(com_pub); } /* * (non-Javadoc) * * @see javax.microedition.lcdui. CommandListener#commandAction (javax.microedition.lcdui.Command, * javax.microedition.lcdui.Displayable) */ public void commandAction (Command arg0, Displayable arg1) { if (arg0 == com_pub) { //發(fā)布service publish(); } else if (arg0 == com_cancel) { cancelService(); } else { cancelService(); midlet.showMainMenu(); } } /** * 內(nèi)部類，服務(wù)端服務(wù)線程。 * @author Jagie * * TODO To change the template for this generated type comment go to * Window - Preferences - Java - Code Style - Code Templates */ private class ClientProcessor implements Runnable { private Thread processorThread; private Vector queue = new Vector(); private boolean isOk = true; ClientProcessor() { processorThread = new Thread(this); processorThread.start(); } public void run() { while (!isClosed) { synchronized (this) { if (queue.size() == 0) { try { //阻塞，直到有新客戶連接 wait(); } catch (InterruptedException e) { } } } //處理連接隊列 StreamConnection conn; synchronized (this) { if (isClosed) { return; } conn = (StreamConnection) queue.firstElement(); queue.removeElementAt(0); processConnection(conn); } } } /** * 往連接隊列添加新連接，同時喚醒處理線程 * @param conn */ void addConnection(StreamConnection conn) { synchronized (this) { queue.addElement(conn); notify(); } } } /** * 從StreamConnection讀取輸入 * @param conn * @return */ private String readInputString (StreamConnection conn) { String inputString = null; try { DataInputStream dis = conn.openDataInputStream(); inputString = dis.readUTF(); dis.close(); } catch (Exception e) { e.printStackTrace(); } return inputString; } /** * debug * @param s */ private void showInfo(String s) { StringBuffer sb = new StringBuffer(this.getString()); if (sb.length() > 0) { sb.append("\n"); } sb.append(s); this.setString(sb.toString()); } /** * 處理客戶端連接 * @param conn */ private void processConnection (StreamConnection conn) { // 讀取輸入 String inputString = readInputString(conn); //生成響應(yīng) String outputString = inputString.toUpperCase(); //輸出響應(yīng) sendOutputData(outputString, conn); try { conn.close(); } catch (IOException e) { } // ignore showInfo("客戶端輸入:" + inputString + ",已成功響應(yīng)!"); } /** * 輸出響應(yīng) * @param outputData * @param conn */ private void sendOutputData (String outputData, StreamConnection conn) { try { DataOutputStream dos = conn.openDataOutputStream(); dos.writeUTF(outputData); dos.close(); } catch (IOException e) { } } }
