sound.java

用java开发的一个实施策略游戏源码 值得学习一下

/*
 *  Copyright (c) 1999 - 2001 by Matthias Pfisterer <[e-mail]>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as published
 *   by the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
package netwar.utils;

import	java.io.File;
import	java.io.IOException;

import	javax.sound.sampled.AudioFormat;
import	javax.sound.sampled.AudioInputStream;
import	javax.sound.sampled.AudioSystem;
import	javax.sound.sampled.DataLine;
import	javax.sound.sampled.LineUnavailableException;
import	javax.sound.sampled.SourceDataLine;

public class Sound
{
	private static AudioInputStream AttackCommand_audioInputStream = null;
	private static AudioInputStream Welcome_audioInputStream = null;
	private SourceDataLine	line = null;
	private static final int	EXTERNAL_BUFFER_SIZE = 128000;

        public Sound(){}

	public void play(String strFilename)
	{
		//Start Daniel's URL hack (to make JARs work)
		//Code based on michael.grimm's contribution to a forum on java.sun.com
		java.net.URL jar[] = new java.net.URL[1];
		jar[0] = null;
		try{jar[0] = ClassLoader.getSystemResource("netwar/media/");}
		catch(Exception e) {}
		java.net.URLClassLoader cl = new java.net.URLClassLoader(jar);
		java.net.URL fileURL = cl.findResource(strFilename);
		//End Daniel's URL hack. Next line is Kyle's original version

		/*
		  We check that there is exactely one command-line
		  argument.
		  If not, we display the usage message and exit.
		*/
//		File	soundFile = new File(strFilename);
	
		/*
		  We have to read in the sound file.
		*/
		AudioInputStream	audioInputStream = null;
		try
		{
			audioInputStream = AudioSystem.getAudioInputStream(fileURL);
//			audioInputStream = AudioSystem.getAudioInputStream(soundFile);
		}
		catch (Exception e)
		{
			/*
			  In case of an exception, we dump the exception
			  including the stack trace to the console output.
			  Then, we exit the program.
			*/
			e.printStackTrace();
			System.exit(1);
		}

		/*
		  From the AudioInputStream, i.e. from the sound file,
		  we fetch information about the format of the
		  audio data.
		  These information include the sampling frequency,
		  the number of
		  channels and the size of the samples.
		  These information
		  are needed to ask Java Sound for a suitable output line
		  for this audio file.
		*/
		
		AudioFormat	audioFormat = audioInputStream.getFormat();

		/*
		  Asking for a line is a rather tricky thing.
		  We have to construct an Info object that specifies
		  the desired properties for the line.
		  First, we have to say which kind of line we want. The
		  possibilities are: SourceDataLine (for playback), Clip
		  (for repeated playback)	and TargetDataLine (for
		  recording).
		  Here, we want to do normal playback, so we ask for
		  a SourceDataLine.
		  Then, we have to pass an AudioFormat object, so that
		  the Line knows which format the data passed to it
		  will have.
		  Furthermore, we can give Java Sound a hint about how
		  big the internal buffer for the line should be. This
		  isn't used here, signaling that we
		  don't care about the exact size. Java Sound will use
		  some default value for the buffer size.
		*/
		DataLine.Info	info = new DataLine.Info(SourceDataLine.class,
							 audioFormat);
		try
		{
			line = (SourceDataLine) AudioSystem.getLine(info);

			/*
			  The line is there, but it is not yet ready to
			  receive audio data. We have to open the line.
			*/
			line.open(audioFormat);
		}
		catch (LineUnavailableException e)
		{
			System.out.println("You appear to not have a sound device configured. The game will still continue.");
		}
		catch (Exception e)
		{
			e.printStackTrace();
			System.exit(1);
		}

		/*
		  Still not enough. The line now can receive data,
		  but will not pass them on to the audio output device
		  (which means to your sound card). This has to be
		  activated.
		*/
		line.start();

		/*
		  Ok, finally the line is prepared. Now comes the real
		  job: we have to write data to the line. We do this
		  in a loop. First, we read data from the
		  AudioInputStream to a buffer. Then, we write from
		  this buffer to the Line. This is done until the end
		  of the file is reached, which is detected by a
		  return value of -1 from the read method of the
		  AudioInputStream.
		*/
                
		int	nBytesRead = 0;
		byte[]	abData = new byte[EXTERNAL_BUFFER_SIZE];
		while (nBytesRead != -1)
		{
			try
			{
				nBytesRead = audioInputStream.read(abData, 0, abData.length);
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
			if (nBytesRead >= 0)
			{
				int	nBytesWritten = line.write(abData, 0, nBytesRead);
			}
		}

		/*
		  Wait until all data are played.
		  This is only necessary because of the bug noted below.
		  (If we do not wait, we would interrupt the playback by
		  prematurely closing the line and exiting the VM.)

		  Thanks to Margie Fitch for bringing me on the right
		  path to this solution.
		*/
		try{
			line.drain();
                } catch(Exception e){}
		/*
		  All data are played. We can close the shop.
		*/
		line.close();

		/*
		  There is a bug in the jdk1.3.
		  It prevents correct termination of the VM.
		  So we have to exit ourselves.
		*/
	}
}



/*** SimpleAudioPlayer.java ***/