如何在黑莓中连续播放音频文件？

Question

我设法在Blackberry中创建播放音频文件的应用程序，但它只播放一个文件。我尝试使用for循环播放一些音频文件。

我设法播放它，但它没有播放音频文件的全部声音，它只播放第一个音频文件，然后播放几秒钟，然后停止播放。播放的文件也播放声音彼此重叠，这不应该发生。

如何在黑莓中一个接一个地播放音频文件的完整声音而不停止？

这里是我的，我与创建for循环的应用程序代码：

package mypackage; 

import javax.microedition.media.Manager; 
import javax.microedition.media.MediaException; 
import javax.microedition.media.Player; 
import java.lang.Class; 
import javax.microedition.rms.RecordStore; 
import java.io.InputStream; 
import java.io.ByteArrayInputStream; 
import net.rim.device.api.media.protocol.ByteArrayInputStreamDataSource; 
import net.rim.device.api.system.*; 
import net.rim.device.api.ui.*; 
import net.rim.device.api.ui.component.*; 
import net.rim.device.api.ui.container.MainScreen; 
import net.rim.device.api.ui.extension.container.*; 
import net.rim.device.api.ui.UiApplication; 
import java.io.IOException; 

public class PlayMedia extends UiApplication{ 
    /** 
    * Entry point for application 
    * @param args Command line arguments (not used) 
    */ 
    public static void main(String[] args){ 

     PlayMedia theApp = new PlayMedia(); 
     theApp.enterEventDispatcher(); 
    } 

    public PlayMedia() 
    { 

     pushScreen(new PlayMediaScreen()); 


    } 
    /** 
    * A class extending the MainScreen class, which provides default standard 
    * behavior for BlackBerry GUI applications. 
    */ 
    final class PlayMediaScreen extends MainScreen 
    { 
     /** 
     * Creates a new PlayMediaScreen object 
     */ 
     PlayMediaScreen() 
     { 
      String test1 = "Test(2seconds).mp3"; 
      String test2 = "Test(2seconds)2.mp3"; 
      String test3 = "Test(2seconds)3.mp3"; 
      String test4 = "Test(2seconds)4.mp3"; 
      String test5 = "blind_willie.mp3"; 
      String mp3 = null; 

      for(int i=0;i<5;i++){ 
       if(i == 0){ 
        mp3 = test1; 
       } 
       else if(i == 1){ 
        mp3 = test2; 
       } 
       else if(i == 2){ 
        mp3 = test3; 
       } 
       else if(i == 3){ 
        mp3 = test4; 
       } 
       else if(i == 4){ 
        mp3 = test5; 
       } 
       play(mp3); 
      } 
     } 

     private void play(String mp3){ 

     Player p = null; 

     InputStream stream = (InputStream)this.getClass().getResourceAsStream("/" + mp3); 

      try { 
       //p = Manager.createPlayer(source); 
       p = Manager.createPlayer(stream, "audio/mpeg"); 
       p.realize(); 
       p.prefetch(); 

       //testing 
       System.out.println("Creating Players!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 
       System.out.println("The mp3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

      } catch (IOException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

       //testing 
       System.out.println("IO Exeception!!!!!!!!!!!!!!!!1 " + e); 

       //testing 
       System.out.println(p); 

      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

      //testing 
      System.out.println("Media Exeception!!!!!!!!!!!!!!!!1" + e); 

      //testing 
      System.out.println(p); 
      } 
      /* 
      * Best practice is to invoke realize(), then prefetch(), then start(). 
      * Following this sequence reduces delays in starting media playback. 
      * 
      * Invoking start() as shown below will cause start() to invoke prefetch(0), 
      * which invokes realize() before media playback is started. 
      */ 
      try { 
       p.start(); 
      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

       //testing 
       System.out.println("Media Exeception for starting!!!!!!!!!!!!!!!!1" + e); 

       //testing 
       System.out.println(p); 
      } 

      /*try { 
       p.stop(); 
      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      }*/ 
      //p.deallocate(); 
      //p.close(); 



     } 
    } 
} 

Answer 1

最后我明白了，这是我的代码。 ：D

package mypackage; 

import javax.microedition.media.Manager; 
import javax.microedition.media.MediaException; 
import javax.microedition.media.Player; 
import javax.microedition.media.PlayerListener; 

import java.lang.Class; 
import javax.microedition.rms.RecordStore; 
import java.io.InputStream; 
import java.io.ByteArrayInputStream; 
import net.rim.device.api.media.protocol.ByteArrayInputStreamDataSource; 
import net.rim.device.api.system.*; 
import net.rim.device.api.ui.*; 
import net.rim.device.api.ui.component.*; 
import net.rim.device.api.ui.container.MainScreen; 
import net.rim.device.api.ui.extension.container.*; 
import net.rim.device.api.ui.UiApplication; 
import java.io.IOException; 

public class PlayMedia extends UiApplication{ 
    /** 
    * Entry point for application 
    * @param args Command line arguments (not used) 
    */ 
    public static void main(String[] args){ 

     PlayMedia theApp = new PlayMedia(); 
     theApp.enterEventDispatcher(); 
    } 

    public PlayMedia() 
    { 

     pushScreen(new PlayMediaScreen()); 


    } 
    /** 
    * A class extending the MainScreen class, which provides default standard 
    * behavior for BlackBerry GUI applications. 
    */ 
    final class PlayMediaScreen extends MainScreen implements PlayerListener 
    { 
     /** 
     * Creates a new PlayMediaScreen object 
     */ 
     Player p = null; 
     String mp3 = ""; 
     String test1 = "Test2seconds.mp3"; 
     String test5 = "Test2seconds2.mp3"; 
     //String test6 = "Test2seconds3.mp3"; 
     String test4 = "Test2seconds4.mp3"; 
     String test2 = "blind_willie.mp3"; 
     String test3 = "blind_willie2.mp3"; 


     PlayMediaScreen() 
     { 
      mp3 = test1; 
      play(mp3); 
     } 

     private void play(String mp3){ 



     InputStream stream = (InputStream)this.getClass().getResourceAsStream("/" + mp3); 

      try { 
       //p = Manager.createPlayer(source); 
       p = Manager.createPlayer(stream,"audio/mpeg"); 
       p.addPlayerListener(this); 
       p.realize(); 
       p.prefetch(); 

       //testing 
       System.out.println("Creating Players!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 
       System.out.println("The mp3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

      } catch (IOException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

       //testing 
       System.out.println("IO Exeception!!!!!!!!!!!!!!!!1 " + e); 

       //testing 
       System.out.println(p); 

      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

      //testing 
      System.out.println("Media Exeception!!!!!!!!!!!!!!!!1" + e); 

      //testing 
      System.out.println(p); 
      } 
      /* 
      * Best practice is to invoke realize(), then prefetch(), then start(). 
      * Following this sequence reduces delays in starting media playback. 
      * 
      * Invoking start() as shown below will cause start() to invoke prefetch(0), 
      * which invokes realize() before media playback is started. 
      */ 
      try { 
       p.start(); 
      } catch (MediaException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 

       //testing 
       System.out.println("Media Exeception for starting!!!!!!!!!!!!!!!!1" + e); 

       //testing 
       System.out.println(p); 
      } 
      /* 
      try { 
       p.stop(); 
      } catch (MediaException e) { 
      // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      p.deallocate(); 
      p.close(); 
      */ 


     } 

     public void playerUpdate(Player player, String event, Object eventData) { 
      // TODO Auto-generated method stub 
      if (event.equals(PlayerListener.END_OF_MEDIA)) { 

       //String mp3 = ""; 

       if(mp3.equals(test1)) { 
        mp3 = test2; 
        //testing 
        System.out.println("The MP3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

        play(mp3); 

        //testing 
        System.out.println("The MP3 FINISH PLAYING is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

       } 
       else if(mp3.equals(test2)){ 
        mp3 = test3; 
        //testing 
        System.out.println("The MP3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

        play(mp3); 

        //testing 
        System.out.println("The MP3 FINISH PLAYING is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

       } 
       else if(mp3.equals(test3)) { 
        mp3 = test4; 
        //testing 
        System.out.println("The MP3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

        play(mp3); 

        //testing 
        System.out.println("The MP3 FINISH PLAYING is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

       }     
       else if(mp3.equals(test4)) { 
        mp3 = test5; 
        //testing 
        System.out.println("The MP3 is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

        play(mp3); 

        //testing 
        System.out.println("The MP3 FINISH PLAYING is " + mp3 + "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"); 

       } 
       else if(mp3.equals(test5)){ 
        mp3 = null; 
        try { 
         player.stop(); 
        } catch (MediaException e) { 
         // TODO Auto-generated catch block 
         e.printStackTrace(); 
        } 
        player.deallocate(); 
        player.close(); 
       } 

       } 
     } 
    } 
} 

Answer 2

我设法发挥它，但它没有播放音频文件的整个声音，它只是玩第一个音频文件，第二个音频文件几秒钟，然后停止播放。播放的文件也播放声音彼此重叠，这不应该发生。

请重读BB API docs为Player小心：

简单回放

玩家可以从管理人的createPlayer方法来创建。播放器创建后，调用start将尽快开始播放。当播放开始时，该方法将返回。播放将在后台继续，到达媒体结束时自动停止播放。

播放简单的例子说明这一点：

try { 
    Player p = Manager.createPlayer("http://abc.wav"); 
    p.start(); 
} catch (MediaException pe) { 
} catch (IOException ioe) { 
} 

说明文档说The method will return when the playback is started. The playback will continue in the background ..。这是你得到“合理重叠”的原因。

为了克服这个问题，你需要在播放器Player.addPlayerListener(PlayerListener playerListener)上附加一个监听器。当媒体文件播放到最后时，将从背景“回放”线程通知监听器。这将是开始下一个媒体文件的新播放的正确时刻。请不要指望我的代码，我只是给你一个想法。