/*
* ID3V2Tag.java
*
* Created on 24-Nov-2003
*
* Copyright (C)2003-2005 Paul Grebenc
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: ID3V2Tag.java,v 1.23 2005/10/27 02:12:20 paul Exp $
*/
package org.blinkenlights.jid3.v2;
import java.io.*;
import java.util.*;
import org.blinkenlights.jid3.*;
import org.blinkenlights.jid3.io.*;
/**
* @author paul
*
* Base class representing all ID3 V2 tags.
*/
abstract public class ID3V2Tag extends ID3Tag
{
/** Flag indicating whether unsynchronization is used in this tag or not. */
protected boolean m_bUnsynchronizationUsedFlag;
/** Flag indicating whether the extended header is present or not. */
protected boolean m_bExtendedHeaderFlag;
/** Flag indicating this tag should be considered experimental. */
protected boolean m_bExperimentalFlag;
/** Flag indicating whether a CRC value exists in the extended header. */
protected boolean m_bCRCDataFlag;
/** Mapping from frame ID to list containing frames. For frames that can only be used once. */
protected Map m_oFrameIdToFrameMap = null;
/** Default padding for ID3 v2 frames, if not specified. 16 bytes, because Winamp does not read the last
* frame when there isn't at least 6 bytes of padding following it in a tag. */
private static int s_iDefaultPaddingLength = 16;
/** Value specifying the amount of padding which is appended to the frames in this tag. */
protected int m_iPaddingLength;
/** Construct an ID3 V2 tag, specifying flag values.
*
* @param bUnsynchronizationUsedFlag specify whether unsynchronization is to be used in this tag or not
* @param bExtendedHeaderFlag specify whether the extended header will be present or not
* @param bExperimentalFlag specify whether this tag is to be considered experimental or not
*/
public ID3V2Tag(boolean bUnsynchronizationUsedFlag,
boolean bExtendedHeaderFlag,
boolean bExperimentalFlag)
{
m_bUnsynchronizationUsedFlag = bUnsynchronizationUsedFlag;
m_bExtendedHeaderFlag = bExtendedHeaderFlag;
m_bExperimentalFlag = bExperimentalFlag;
m_oFrameIdToFrameMap = new HashMap();
//HACK: Default padding of 16 bytes, because Winamp doesn't seem to see the last frame in a v2 tag
// when there is less than 6 bytes of padding. (???)
m_iPaddingLength = s_iDefaultPaddingLength;
}
/** Get all frames set in this tag which can only be stored once in the tag.
* This method exists to aid in testing.
*/
public ID3V2Frame[] getSingleFrames()
{
return (ID3V2Frame[])m_oFrameIdToFrameMap.values().toArray(new ID3V2Frame[0]);
}
/** Check if this tag contains at least one frame. An ID3V2 tag requires at least one frame to be written.
*
* @return true if this tag contains at least one frame, and false otherwise
*/
abstract public boolean containsAtLeastOneFrame();
abstract public void sanityCheck() throws ID3Exception;
/** Write this tag to an output stream.
*
* @param oOS the output stream to which this tag is to be written
* @throws ID3Exception if an error occurs while writing
*/
abstract public void write(OutputStream oOS) throws ID3Exception;
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString()
{
StringBuffer sbText = new StringBuffer();
sbText.append("Unsynchronization: " + m_bUnsynchronizationUsedFlag +
"\nExtended header: " + m_bExtendedHeaderFlag +
"\nExperimental: " + m_bExperimentalFlag +
"\nCRC: " + m_bCRCDataFlag +
"\nPadding length: " + + m_iPaddingLength +
"\nNum frames: " + m_oFrameIdToFrameMap.size());
Iterator oIter = m_oFrameIdToFrameMap.keySet().iterator();
while(oIter.hasNext())
{
String sFrameId = (String)oIter.next();
sbText.append("\n" + ((ID3V2Frame)m_oFrameIdToFrameMap.get(sFrameId)));
}
return sbText.toString();
}
/** Read a tag from an input stream.
*
* @param oIS the input stream from which to read a tag
* @return the tag read
* @throws ID3Exception if an error occurs while reading the tag
*/
public static ID3V2Tag read(InputStream oIS)
throws ID3Exception
{
try
{
ID3DataInputStream oID3DIS = new ID3DataInputStream(oIS);
// check which version of v2 tags we have
int iMinorVersion = oID3DIS.readUnsignedByte();
int iPatchVersion = oID3DIS.readUnsignedByte();
if (iMinorVersion == 3)
{
// there is a tag, we must read it
ID3V2Tag oID3V2Tag = ID3V2_3_0Tag.internalRead(oID3DIS);
return oID3V2Tag;
}
else
{
//TODO: If we're going to support >2.3.0 tags, do that here.
return null;
}
}
catch (ID3Exception e)
{
throw e;
}
catch (Exception e)
{
throw new ID3Exception("Error reading tag.", e);
}
}
/** Set the unsynchronization status.
*
* @param bUnsynchronizationUsed an indication of whether unsynchronization should be used when writing this tag
*/
public void setUnsynchronization(boolean bUnsynchronizationUsed)
{
m_bUnsynchronizationUsedFlag = bUnsynchronizationUsed;
}
/** Get the current unsynchronization status for this tag.
*
* @return the current status of the unsynchronization flag
*/
public boolean getUnsynchronization()
{
return m_bUnsynchronizationUsedFlag;
}
/** Set the extended header flag for this tag.
*
* @param bExtendedHeaderUsed an indication of whether the extended header should be included in this tag
*/
public void setExtendedHeader(boolean bExtendedHeaderUsed)
{
m_bExtendedHeaderFlag = bExtendedHeaderUsed;
}
/** Get the current extended header status for this tag.
*
* @return the current status of the extended header flag
*/
public boolean getExtendedHeader()
{
return m_bExtendedHeaderFlag;
}
/** Set the CRC flag (extended header must be enabled before this flag can be set.
*
* @param bCRCUsed an indication of whether a CRC value should be included in the extended header of this tag
*/
public void setCRC(boolean bCRCUsed)
throws ID3Exception
{
if ( ! m_bExtendedHeaderFlag)
{
throw new ID3Exception("The CRC flag cannot be set unless the extended header flag is set first.");
}
m_bCRCDataFlag = bCRCUsed;
}
/** Get the current CRC status for the extended header in this frame.
*
* @return true if the extended header is enabled, and the CRC flag is also enabled, or false otherwise
*/
public boolean getCRC()
{
return m_bCRCDataFlag;
}
/** Set the default padding length to be added at the end of newly created tags.
*
* NOTE: When read by Winamp, it seems the last frame in a v2 tag is not seen, unless there are at least six bytes
* of padding at the end of the tag. For this reason, the default padding at the end of v2 tags is set to 16.
* This value can be modified if desired, but be aware of this observation regarding Winamp.
*
* @param iPaddingLength the padding length to use
* @throws ID3Exception if the padding length value is negative
*/
public static void setDefaultPaddingLength(int iPaddingLength)
throws ID3Exception
{
if (iPaddingLength < 0)
{
throw new ID3Exception("Padding length in ID3 V2 tag cannot be negative.");
}
s_iDefaultPaddingLength = iPaddingLength;
}
/** Set the padding length to be added at the end of this tag.
*
* NOTE: When read by Winamp, it seems the last frame in a v2 tag is not seen, unless there are at least six bytes
* of padding at the end of the tag. For this reason, the default padding at the end of v2 tags is set to 16.
* This value can be modified if desired, but be aware of this observation regarding Winamp.
*
* @param iPaddingLength the padding length to use
* @throws ID3Exception if the padding length value is negative
*/
public void setPaddingLength(int iPaddingLength)
throws ID3Exception
{
if (iPaddingLength < 0)
{
throw new ID3Exception("Padding length in ID3 V2 tag cannot be negative.");
}
m_iPaddingLength = iPaddingLength;
}
/** Get the default padding length currently set for newly created tags.
*
* @return the current padding length
*/
public static int getDefaultPaddingLength()
{
return s_iDefaultPaddingLength;
}
/** Get the padding length currently set for this tag.
*
* @return the current padding length
*/
public int getPaddingLength()
{
return m_iPaddingLength;
}
/** Convenience method for setting artist directly from tag.
*
* @param sArtist the artist name
* @throws ID3Exception
*/
abstract public void setArtist(String sArtist) throws ID3Exception;
/** Convenience method for retrieving artist directly from tag.
*
* @return the artist value currently set
* @throws ID3Exception
*/
abstract public String getArtist();
/** Convenience method for setting song title directly from tag.
*
* @param sTitle the song title
* @throws ID3Exception
*/
abstract public void setTitle(String sTitle) throws ID3Exception;
/** Convenience method for retrieving song title directly from tag.
*
* @return the song title currently set
* @throws ID3Exception
*/
abstract public String getTitle();
/** Convenience method for setting album title directly from tag.
*
* @param sAlbum the album title
* @throws ID3Exception
*/
abstract public void setAlbum(String sAlbum) throws ID3Exception;
/** Convenience method for retrieving album title directly from tag.
*
* @return the album title currently set
* @throws ID3Exception
*/
abstract public String getAlbum();
/** Convenience method for setting year directly from tag.
*
* @return the year of the recording
* @throws ID3Exception
*/
abstract public void setYear(int iYear) throws ID3Exception;
/** Convenience method for retrieving year directly from tag.
*
* @return the year currently set
* @throws ID3Exception if no year was set
*/
abstract public int getYear() throws ID3Exception;
/** Convenience method for setting track number directly from tag.
*
* @param iTrackNumber the track number
* @throws ID3Exception
*/
abstract public void setTrackNumber(int iTrackNumber) throws ID3Exception;
/** Convenience method for setting track number and total number of tracks directly from tag.
*
* @param iTrackNumber the track number
* @param iTotalTracks the total number of tracks
* @throws ID3Exception
*/
abstract public void setTrackNumber(int iTrackNumber, int iTotalTracks) throws ID3Exception;
/** Convenience method for retrieving track number directly from tag.
*
* @return the track number currently set
* @throws ID3Exception if not track number was set
*/
abstract public int getTrackNumber() throws ID3Exception;
/** Convenience method for retrieving total number of tracks directly from tag.
*
* @return the total number of tracks currently set
* @throws ID3Exception if total number of tracks was not set
*/
abstract public int getTotalTracks() throws ID3Exception;
/** Convenience method for setting genre directly from tag.
*
* @param sGenre the genre (free-form)
* @throws ID3Exception
*/
abstract public void setGenre(String sGenre) throws ID3Exception;
/** Convenience method for retrieving the genre directly from tag.
*
* @return the genre currently set
* @throws ID3Exception
*/
abstract public String getGenre();
/** Convenience method for setting comment directly from tag.
*
* @param sComment the comment
* @throws ID3Exception
*/
abstract public void setComment(String sComment) throws ID3Exception;
/** Convenience method for retrieving the comment directly from tag.
*
* @return the comment currently set
* @throws ID3Exception
*/
abstract public String getComment();
}
|
