mp3player.java

用Java编写的一个可下载MP3

package org.serain.shmily.player;

import java.io.*;
import javazoom.jl.player.*;
import javazoom.jl.decoder.*;


public class Mp3Player extends Thread {
    private boolean play=true;
    private boolean stop=false;
    public Mp3Player(File file) throws FileNotFoundException, JavaLayerException{
        this(new BufferedInputStream(new FileInputStream(file)));
    }
    public void pause(){
        play=false;
    }    
    public void play(){
        play=true;
    }   
    public void stope(){
        stop=true;
        close();
    }   
    public  void run() {
	boolean ret = true;
	int frames=Integer.MAX_VALUE;
        while(!stop){ 
             if(play==true){
		if ((frames-- > 0)==true && ret==true){
                    try {
                          ret = decodeFrame();
                    } catch (JavaLayerException ex) {
                          ex.printStackTrace();
                   }
		}		
		if (!ret){
                        stop=true;
			AudioDevice out = audio;
			if (out!=null){				
				out.flush();
				synchronized (this){
					complete = (!closed);
					close();
				}				
			}
                        synchronized(this){
                            notify();//唤醒歌曲切换监听器
                        }
		}
             }
         }    
   }

    public boolean isPlay() {
        return play;
    }

    public void setPlay(boolean play) {
        this.play = play;
    }

    public boolean isStop() {
        return stop;
    }

    public void setStop(boolean stop) {
        this.stop = stop;
    }

    public boolean isClosed() {
        return closed;
    }

    public void setClosed(boolean closed) {
        this.closed = closed;
    }
       
       
       
       
       
       
       
       
       
       
       
       
       
       /**
	 * The current frame number. 
	 */
	private int frame = 0;
	
	/**
	 * The MPEG audio bitstream. 
	 */
	// javac blank final bug. 
	/*final*/ private Bitstream		bitstream;
	
	/**
	 * The MPEG audio decoder. 
	 */
	/*final*/ private Decoder		decoder; 
	
	/**
	 * The AudioDevice the audio samples are written to. 
	 */
	private AudioDevice	audio;
	
	/**
	 * Has the player been closed?
	 */
	private boolean		closed = false;
	
	/**
	 * Has the player played back all frames from the stream?
	 */
	private boolean		complete = false;

	private int			lastPosition = 0;
	
	/**
	 * Creates a new <code>Player</code> instance. 
	 */
	public Mp3Player(InputStream stream) throws JavaLayerException
	{
		this(stream, null);	
	}
	
	public Mp3Player(InputStream stream, AudioDevice device) throws JavaLayerException
        {
		bitstream = new Bitstream(stream);		
		decoder = new Decoder();
				
		if (device!=null)
		{		
			audio = device;
		}
		else
		{			
			FactoryRegistry r = FactoryRegistry.systemRegistry();
			audio = r.createAudioDevice();
		}
		audio.open(decoder);
	}		
	/**
	 * Cloases this player. Any audio currently playing is stopped
	 * immediately. 
	 */
	public synchronized void close()
	{		
		AudioDevice out = audio;
		if (out!=null)
		{ 
			closed = true;
			audio = null;	
			// this may fail, so ensure object state is set up before
			// calling this method. 
			out.close();
			lastPosition = out.getPosition();
			try
			{
				bitstream.close();
			}
			catch (BitstreamException ex)
			{
			}
		}
	}
	
	/**
	 * Returns the completed status of this player.
	 * 
	 * @return	true if all available MPEG audio frames have been
	 *			decoded, or false otherwise. 
	 */
	public synchronized boolean isComplete()
	{
		return complete;	
	}
				
	/**
	 * Retrieves the position in milliseconds of the current audio
	 * sample being played. This method delegates to the <code>
	 * AudioDevice</code> that is used by this player to sound
	 * the decoded audio samples. 
	 */
	public int getPosition()
	{
		int position = lastPosition;
		
		AudioDevice out = audio;		
		if (out!=null)
		{
			position = out.getPosition();	
		}
		return position;
	}		
	
	/**
	 * Decodes a single frame.
	 * 
	 * @return true if there are no more frames to decode, false otherwise.
	 */
	protected boolean decodeFrame() throws JavaLayerException
	{		
		try
		{
			AudioDevice out = audio;
			if (out==null)
				return false;

			Header h = bitstream.readFrame();	
			
			if (h==null)
				return false;
				
			// sample buffer set when decoder constructed
			SampleBuffer output = (SampleBuffer)decoder.decodeFrame(h, bitstream);
																																					
			synchronized (this)
			{
				out = audio;
				if (out!=null)
				{					
					out.write(output.getBuffer(), 0, output.getBufferLength());
				}				
			}
																			
			bitstream.closeFrame();
		}		
		catch (RuntimeException ex)
		{
			throw new JavaLayerException("Exception decoding audio frame", ex);
		}
		
		return true;
	}

}