熟练使用J2ME可选包MMAPI

    本文的目的是为读者提供处理不同情况的代码，您可以参考MMAPI DOC。

1. 播放单音
   try {
       Manager.playTone(ToneControl.C4, 5000 /* millisec */, 100 /* max vol */);
   } catch (MediaException e) { }
   
2. 简单媒体重放功能实现
   try {
       Player p = Manager.createPlayer("http://webserver/music.mp3");
       p.setLoopCount(5);
       p.start();
   } catch (IOException ioe) {
   } catch (MediaException me) { }
   
3. 详细重放控制
   static final long SECS_TO_MICROSECS = 1000000L;
   Player p;
   VolumeControl vc;
   try {
       p = Manager.createPlayer("http://webserver/music.mp3");
       p.realize();
      // Set a listener.
      p.addPlayerListener(new Listener());
      // Grab volume control for the player.
      // Set Volume to max.
      vc = (VolumeControl)p.getControl("VolumeControl");
      if (vc != null)
         vc.setLevel(100);
      // Set a start time.
      p.setMediaTime(5 * SECS_TO_MICROSECS);
      // Guarantee that the player can start with the smallest latency.
      p.PRefetch();
      // Non-blocking start
      p.start();
   } catch (IOException ioe) {
   } catch (MediaException me) { }
   class Listener implements PlayerListener {
       public void playerUpdate(Player p, String event, Object eventData) {
           if (event == END_OF_MEDIA event == STOP_AT_TIME) {
               System.out.println("Done processing");
               try {
                   p.setMediaTime(5 * SECS_TO_MICROSECS);
                   p.start();
               } catch (MediaException me) { }
               break;
           }
       }
   }
   
4. 实现MIDI重放控制
   

   Player p;TempoControl tc;try {    p = Manager.createPlayer("http://webserver/tune.mid");    p.realize();    // Grab the tempo control.    tc = (TempoControl)p.getControl("TempoControl");    tc.setTempo(120000); // 120 beats/min    p.start();} catch (IOException ioe) {} catch (MediaException me) { }

5. 视频重放功能实现
   

   Player p;
               VideoControl vc;try {    p = Manager.createPlayer("http://webserver/movie.mpg");    p.realize();    // Grab the video control and set it to the current display.    vc = (VideoControl)p.getControl("VideoControl");    if (vc != null) {        Form form = new Form("video");        form.append((Item)vc.initDisplayMode(vc.USE_GUI_PRIMITIVE, null));        Display.getDisplay(midlet).setCurrent(form);    }    p.start();} catch (IOException ioe) {} catch (MediaException me) { }

6. 播放RMS内存储的数据
   

   RecordStore rs;int recordID;   :  // code to set up the record store.try {    InputStream is = new    ByteArrayInputStream(rs.getRecord(recordID));    Player p = Manager.createPlayer(is, "audio/X-wav");    p.start();} catch (IOException ioe) {} catch (MediaException me) { }

7. 播放Jar文件中存储的媒体
   

   /** Notice that in MIDP 2.0, the wav format is mandatory only *//** in the case that the device supports sampled audio.       */try {    InputStream is = getClass().getResourceAsStream("audio.wav");    Player p = Manager.createPlayer(is, "audio/X-wav");    p.start();} catch (IOException ioe) {} catch (MediaException me) { }

8. 不同Player的同步
   

   Player p1, p2;try {    p1 = Manager.createPlayer("http://webserver/tune.mid");    p1.realize();    p2 = Manager.createPlayer("http://webserver/movie.mpg");    p2.realize();    p2.setTimeBase(p1.getTimeBase());    p1.prefetch();    p2.prefetch();    p1.start();    p2.start();} catch (IOException ioe) {} catch (MediaException me) { }

9. 产生单音序列
   byte tempo = 30; // set tempo to 120 bpm
   byte d = 8;      // eighth-note
   
   byte C4 = ToneControl.C4;;
   byte D4 = (byte)(C4 + 2); // a whole step
   byte E4 = (byte)(C4 + 4); // a major third
   byte G4 = (byte)(C4 + 7); // a fifth
   byte rest = ToneControl.SILENCE; // rest
   
   byte[] mySequence = {
       ToneControl.VERSION, 1,   // version 1
       ToneControl.TEMPO, tempo, // set tempo
       ToneControl.BLOCK_START, 0,   // start define "A" section
       E4,d, D4,d, C4,d, E4,d,       // content of "A" section
       E4,d, E4,d, E4,d, rest,d,          
       ToneControl.BLOCK_END, 0,     // end define "A" section
       ToneControl.PLAY_BLOCK, 0,    // play "A" section
       D4,d, D4,d, D4,d, rest,d,     // play "B" section
       E4,d, G4,d, G4,d, rest,d,
       ToneControl.PLAY_BLOCK, 0,    // repeat "A" section
       D4,d, D4,d, E4,d, D4,d, C4,d  // play "C" section
   };
   
   try{
       Player p = Manager.createPlayer(Manager.TONE_DEVICE_LOCATOR);
       p.realize();
       ToneControl c = (ToneControl)p.getControl("ToneControl");
       c.setSequence(mySequence);
       p.start();
   } catch (IOException ioe) {
   } catch (MediaException me) { }
   
10. 语音捕获和录音功能的实现
    

    try {    // Create a DataSource that captures live audio.    Player p = Manager.createPlayer("capture://audio");    p.realize();    // Get the RecordControl, set the record location, and     // start the Player and record for 5 seconds.    RecordControl rc = (RecordControl)p.getControl("RecordControl");    rc.setRecordLocation("file:/tmp/audio.wav");    rc.startRecord();    p.start();    Thread.currentThread().sleep(5000);    p.stop();    rc.stopRecord();    rc.commit();} catch (IOException ioe) {} catch (MediaException me) {} catch (InterruptedException e) { }

11. 实现摄像功能
    Player p;VideoControl vc;// initialize camera try {    p = Manager.createPlayer("capture://video");    p.realize();    // Grab the video control and set it to the current display.    vc = (VideoControl)p.getControl("VideoControl");    if (vc != null) {        Form form = new Form("video");        form.append((Item)vc.initDisplayMode(vc.USE_GUI_PRIMITIVE, null));        Display.getDisplay(midlet).setCurrent(form);    }    p.start();} catch (IOException ioe) {} catch (MediaException me) { }// now take a picturetry {    byte[] pngImage = vc.getSnapshot(null);    // do something with the image ...} catch (MediaException me) { }
    
    
    在后面的文章中我们将通过完整的实例演示如何使用MMAPI开发应用程序。   

（出处：http://www.VeVb.com）