audioplayer.java

j2me手机上的音频开发

/*
 * @(#)AudioPlayer.java	1.6 04/03/10
 *
 * Copyright (c) 2000-2004 Sun Microsystems, Inc. All rights reserved.
 * PROPRIETARY/CONFIDENTIAL
 * Use is subject to license terms
 */

package example.audiodemo;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.control.*;
import java.util.*;
import java.io.*;

/**
 * This is a demo midlet to show the basic audio functionalities, to
 * play wave file, tone, tone sequence from http, resource jar file
 * and record store.
 *
 * @version 1.6
 *
 */


public class AudioPlayer extends MIDlet implements CommandListener {
    private static PlayerCanvas   playerGUI = null;
    private static List           theList;
    private static Vector         urls;

    private Command               exitCommand = new Command("Exit",
							    Command.EXIT, 1);
    private Command               playCommand = new Command("Play",
							    Command.ITEM, 1);

    private Display               display;

    // pause/resume support
    private boolean restartOnResume = false;


    public AudioPlayer() {
	super();
	display  = Display.getDisplay(this);
	initPlayList();
	display.setCurrent(theList);
    }

    public static List getList() {
	return theList;
    }


    /**
     * Called when this MIDlet is started for the first time,
     * or when it returns from paused mode.
     * If a player is visible, and it was playing
     * when the MIDlet was paused, call its playSound method.
     */
    public void startApp() {
	if (playerGUI != null && restartOnResume) {
	    playerGUI.playSound();
	}
	restartOnResume = false;
    }


    /**
     * Called when this MIDlet is paused.
     * If the player GUI is visible, call its pauseSound method.
     * For consistency across different VM's
     * it's a good idea to stop the player if it's currently
     * playing.
     */
    public void pauseApp() {
	restartOnResume = (playerGUI != null && playerGUI.isPlaying());
	if (restartOnResume) {
	    playerGUI.pauseSound();
	}
    }


    /**
     * Destroy must cleanup everything not handled
     * by the garbage collector.
     */
    public void destroyApp(boolean unconditional) {
	if (playerGUI != null) {
	    playerGUI.stopSound();
	    playerGUI = null;
	}
	display.setCurrent(null);
    }

    public void commandAction(Command c, Displayable s) {
	if (c == exitCommand) {
	    destroyApp(true);
	    notifyDestroyed();
	} else if ((s == theList && c == List.SELECT_COMMAND) ||
		   c == playCommand) {
	    int i = theList.getSelectedIndex();
	    if (i == 0) { // Simple tone
		try {
		    Manager.playTone(60, 200, 90);
		} catch (MediaException ex) {
		    System.out.println("can't play tone");
		}
	    } else if (i > 0) {
		if (playerGUI == null)
		    playerGUI = new PlayerCanvas(display);
		else
		    playerGUI.stopSound();

		playerGUI.setParam((String) urls.elementAt(i));
		playerGUI.playSound();
		display.setCurrent(playerGUI);
	    }
	}
    }

    /**
     * load the play list from thd jad file
     *
     **/
    private void initPlayList() {
	urls = new Vector();

	theList  = new List("MIDP Audio Player", Choice.IMPLICIT);

	for (int n = 1; n < 32; n++) {
	    String nthURL = "PlayerURL-"+ n;
	    String url = getAppProperty(nthURL);
	    if (url == null || url.length() == 0) {
		break;
	    }
	    String nthTitle = "PlayerTitle-" + n;
	    String title = getAppProperty(nthTitle);
	    if (title == null || title.length() == 0) {
		title = url;
	    }
	    urls.addElement(url);
	    theList.append(title, null);
	}

	theList.addCommand(exitCommand);
	theList.addCommand(playCommand);
	theList.setCommandListener(this);
    }
}