btmidlet.java

j2me简单实例,j2me教程加源码,希望大家喜欢

package com.j2medev.chapter9;

import java.io.IOException;
import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.control.VideoControl;
import javax.microedition.midlet.MIDlet;

public class BTMIDlet extends MIDlet implements CommandListener{
    
    private Display display = null;
    private List menu = null;
    private Form form = null;
    private Player player = null;
    private VideoControl vc = null;
    private Thread server = null;
    //存储拍照的图片数据
    private byte[] image = null;
    private Command captureCommand = new Command("capture",Command.OK,1);
    private Command exitCommand = new Command("exit",Command.EXIT,1);
    private Command backCommand = new Command("back",Command.BACK,1);
    private Command sendCommand = new Command("send by bluetooth",Command.OK,1);
    private Command serverCommand = new Command("start server",Command.OK,1);
    public static final String[] MENUS = {"receiver picture","send picture"};
    
    public void startApp() {
        if(display == null){
            display = Display.getDisplay(this);
            menu = new List("share",List.IMPLICIT,MENUS,null);
            menu.setCommandListener(this);
        }
        //显示主菜单
        display.setCurrent(menu);
    }
    
    public void pauseApp() {
    }
    
    public void destroyApp(boolean unconditional) {
        releasePlayer();
    }
    
    private void startPlayer(){
        if(player == null){
            try {
                //创建Player
                player = Manager.createPlayer("capture://video");
                player.realize();
                vc = (VideoControl)player.getControl("VideoControl");
                if(vc != null){
                    //把Item追加到Form上
                    form.append((Item)vc.initDisplayMode(VideoControl.USE_GUI_PRIMITIVE,null));
                }
                player.start();
                form.addCommand(captureCommand);
            } catch (IOException ex) {
                ex.printStackTrace();
            } catch (MediaException ex) {
                ex.printStackTrace();
            }
        }
    }
    //非常重要，释放player
    private void releasePlayer(){
        if(player != null){
            player.close();
            player = null;
        }
    }
    public byte[] getImage(){
        return image;
    }
    public static Alert getAlert(String msg,AlertType type,int timeout){
        Alert a = new Alert("alert",msg,null,type);
        a.setTimeout(timeout);
        return a;
    }
    //服务器启动后 回调此函数
    public void btServerReady(){
        form.append("device is ready and waiting other bluetooth device to send picture...");
    }
    //接收到图片后回调此函数
    public void imageReceived(byte[] data){
        Image img = Image.createImage(data,0,data.length);
        form.append(img);
    }
    public void commandAction(Command command, Displayable displayable) {
        if(command.getCommandType() == Command.EXIT){
            destroyApp(false);
            notifyDestroyed();
        }else if(command == List.SELECT_COMMAND){
            int index = menu.getSelectedIndex();
            if(form == null)
                form = new Form("");
            form.deleteAll();
            if(index == 0){
                //启动服务器端
                form.setTitle("receive picture");
                BTServer bts = new BTServer(this);
                if(server == null)
                    server = new Thread(bts);
                server.start();
            }else if(index == 1){
                //启动客户端，准备拍照
                form.setTitle("capture");
                startPlayer();
                form.addCommand(backCommand);
            }
            form.setCommandListener(this);
            display.setCurrent(form);
        }else if(command == captureCommand){
            //拍照
            new Thread(){
                public void run(){
                    try {
                        image = vc.getSnapshot(null);
                    } catch (MediaException ex) {
                        ex.printStackTrace();
                    }
                    //清除以前的拍照屏幕
                    form.deleteAll();
                    form.append(Image.createImage(image,0,image.length));
                    form.addCommand(sendCommand);
                    form.removeCommand(captureCommand);
                    //不要忘记释放Player
                    releasePlayer();
                }
            }.start();
        }else if(command == sendCommand){
            //经过蓝牙发送图片
            BTClient client = new BTClient(this);
        }
    }
}