shoutcastmetadata.java

来自「java语言开发的P2P流媒体系统」· Java 代码 · 共 137 行

/* 
 * P2P-Radio - Peer to peer streaming system
 * Project homepage: http://p2p-radio.sourceforge.net/
 * Copyright (C) 2003-2004 Michael Kaufmann <[e-mail]>
 * 
 * ---------------------------------------------------------------------------
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * ---------------------------------------------------------------------------
 */

package p2pradio.sources;

import p2pradio.Metadata;


/**
 * Translates Shoutcast Metadata to a {@link Metadata} object and back.
 *
 * @author Michael Kaufmann
 */
public class ShoutcastMetadata
{
	private ShoutcastMetadata()
	{
		// Keine Instanzen
	}
	
	// Beispiel f黵 einen Shoutcast-Metadatenstring:
	// "StreamTitle='Beatles - Hello Goodbye';StreamUrl='';"

	public static void shoutcastToMetadata(byte[] shoutcastMetadataBytes, int shoutcastMetadataBytesLength, Metadata metadata)
	{
		// Den Metadatenstring extrahieren
		
		String shoutcastMetadata = new String(shoutcastMetadataBytes, 0, shoutcastMetadataBytesLength);				
		
		// Bis zu 15 Null-Bytes k鰊nten vorkommen
		shoutcastMetadata = shoutcastMetadata.trim();
		
		// Lied-Titel auslesen
		String songTitle = null;
		
		String streamTitle = "streamtitle='"; //$NON-NLS-1$
		String streamUrl = "streamurl='"; //$NON-NLS-1$
		
		int titlePos = shoutcastMetadata.toLowerCase().indexOf(streamTitle);
		
		if (titlePos != -1)
		{
			titlePos += streamTitle.length();
				
			int titleEndPos = shoutcastMetadata.indexOf("';", titlePos); //$NON-NLS-1$
			
			if (titleEndPos != -1)
			{
				songTitle = shoutcastMetadata.substring(titlePos, titleEndPos);
			} 	
		}
		
		if (songTitle == null)
		{
			songTitle = Metadata.SONG_TITLE_DEFAULT;
		}
		
		
		// Lied-URL auslesen
		String songURL = null;
		
		int urlPos = shoutcastMetadata.toLowerCase().indexOf(streamUrl);
		
		if (urlPos != -1)
		{
			urlPos += streamUrl.length();
			
			int urlEndPos = shoutcastMetadata.indexOf("';", urlPos); //$NON-NLS-1$
			
			if (urlEndPos != -1)
			{
				songURL = shoutcastMetadata.substring(urlPos, urlEndPos);
			} 	
		}
		
		if (songURL == null)
		{
			songURL = Metadata.SONG_URL_DEFAULT;
		}
						
		// In die Metadaten einf黦en
		metadata.setSongTitle(songTitle);
		metadata.setSongURL(songURL);
	}		
	
	public static int metadataToShoutcast(Metadata metadata, byte[] shoutcastMetadataBytes)
	{
		// Den Shoutcast-Metadatenstring erstellen
		String shoutcastMetadataString = "StreamTitle='" + metadata.getSongTitle() + "';StreamUrl='" + metadata.getSongURL() + "';"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		
		// In ein Byte-Array konvertieren
		byte[] shoutcastMetadataStringBytes = shoutcastMetadataString.getBytes();
		
		int length = shoutcastMetadataStringBytes.length;
		
		if (length % 16 != 0)
		{
			// Die L鋘ge durch 16 teilbar machen
			int newlength = length - (length % 16) + 16;
			
			// Array kopieren
			System.arraycopy(shoutcastMetadataStringBytes, 0, shoutcastMetadataBytes, 0, length);
			
			// Den Rest mit Nullen auff黮len
			java.util.Arrays.fill(shoutcastMetadataBytes, length, newlength, (byte)0);
			
			length = newlength;
		}
		else
		{
			// Array kopieren
			System.arraycopy(shoutcastMetadataStringBytes, 0, shoutcastMetadataBytes, 0, length);
		}
			
		return length;
	}
}