midiplayer.java

J2me唆哈的代码

/*
 * Created on 2005-9-28 by pcy
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package a.a.a.mmedia;

import javax.microedition.media.Control;
import javax.microedition.media.MediaException;
import javax.microedition.media.PlayerListener;
import javax.sound.midi.*;

public class MidiPlayer extends BasicPlayer implements Runnable {

    private Sequence sequence = null;
    private Sequencer sequencer;
    private Thread thread;
    
    public MidiPlayer() {
        super();
        
    }

    protected void doRealize() throws MediaException {
        try{
            if(stream!=null){
                sequence=MidiSystem.getSequence(stream);
                sequencer=MidiSystem.getSequencer();
                sequencer.setSequence(sequence);
                sequencer.open();
            }
        }catch(Exception e){
            throw new MediaException(e.getMessage());
        }        
    }

    protected void doPrefetch() throws MediaException {
        
    }

    protected boolean doStart() {
        if(thread!=null){
            thread.interrupt();
            thread=null;
        }
        thread=new Thread(this);
        thread.start();
        return true;
    }

    protected void doStop() {
        if(sequencer!=null&&sequencer.isRunning()){
            sequencer.stop();
        }
    }

    protected void doDeallocate() {
        if(sequencer!=null&&sequencer.isOpen()){
            sequencer.close();
        }
        sequence=null;
        sequencer=null;
        if(thread!=null){
            thread.interrupt();
            thread=null;        
        }
    }

    protected void doClose() {
        if(sequencer!=null&&sequencer.isOpen()){
            sequencer.close();
        }
    }

    protected long doSetMediaTime(long now) throws MediaException {
        
        sequencer.setMicrosecondPosition(now);
        return sequencer.getMicrosecondPosition();
    }

    protected long doGetMediaTime() {

        return sequencer.getMicrosecondPosition();
    }

    protected long doGetDuration() {

        return sequencer.getMicrosecondLength();
    }

    protected Control doGetControl(String type) {
        if ((getState() >= REALIZED) && 
                type.equals("javax.microedition.media.control.VolumeControl")) {
                return this;
        }
        return null;
    }

    protected int doSetLevel(int vol) {
        try{
            MidiChannel[] channels=MidiSystem.getSynthesizer().getChannels();
            if(channels!=null){
                for(int i=0; i<channels.length; ++i){
                    if(vol<=0){
                        channels[i].allNotesOff();
                        channels[i].allSoundOff();
                        channels[i].setMute(true);
                    }else{
                        channels[i].controlChange(0x7,0);
                        channels[i].controlChange(0x27,0);
                    }
                }
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        return vol;
    }

    public void run() {
        if(sequencer!=null&&sequencer.isOpen()){
            sequencer.start();
            while (sequencer.isRunning() && thread != null) {
                try {
                    Thread.sleep(300);
                }catch (Exception e) {
                    break;
                }
            }
            this.sendEvent(PlayerListener.END_OF_MEDIA,null);
        }
        if(thread!=null){
            thread.interrupt();
            thread=null;
        }
    }

    public String getContentType() {
        chkClosed(true);
        return "audio/midi";
    }

}