/*
* LINKID3V2Frame.java
*
* Created on Feb 1, 2004
*
* Copyright (C)2004,2005 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: LINKID3V2Frame.java,v 1.10 2005/02/06 18:11:24 paul Exp $
*/
package org.blinkenlights.jid3.v2;
import java.io.*;
import java.util.*;
import org.blinkenlights.jid3.*;
import org.blinkenlights.jid3.io.*;
import org.blinkenlights.jid3.util.*;
/** Frame containing linked frame information.
*
* @author paul
*/
public class LINKID3V2Frame extends ID3V2Frame
{
//NOTE: Shouldn't the frame identifier be _four_ bytes, not three, as described
// in the spec?
private byte[] m_abyFrameIdentifier = null;
private String m_sURL = null;
private String m_sAdditionalData = null;
/** Constructor
*
* @param abyFrameIdentifier the frame identifier of the frame linked to
* @param sURL a reference to the location of the linked frame
* @param sAdditionalData any additional data which may be needed to retrieve the linked frame
* @throws ID3Exception if a frame identifier of four bytes is not specified, or if the URL is not specified
*/
public LINKID3V2Frame(byte[] abyFrameIdentifier, String sURL, String sAdditionalData)
throws ID3Exception
{
if (abyFrameIdentifier == null)
{
throw new ID3Exception("LINK frame requires frame identifier.");
}
if (abyFrameIdentifier.length != 4)
{
throw new ID3Exception("Frame identifiers must be four bytes in length in LINK frame.");
}
m_abyFrameIdentifier = abyFrameIdentifier;
if ((sURL == null) || (sURL.length() == 0))
{
throw new ID3Exception("LINK frame requires an URL.");
}
m_sURL = sURL;
m_sAdditionalData = sAdditionalData;
}
public LINKID3V2Frame(InputStream oIS)
throws ID3Exception
{
try
{
ID3DataInputStream oFrameDataID3DIS = new ID3DataInputStream(oIS);
// frame identifier (this is probably wrong... it should probably be four
// bytes.. if anyone ever uses this (?) it might break
m_abyFrameIdentifier = new byte[4];
oFrameDataID3DIS.readFully(m_abyFrameIdentifier);
// url
m_sURL = oFrameDataID3DIS.readStringToNull();
// id and additional data
if (oFrameDataID3DIS.available() > 0)
{
byte[] abyAdditionalData = new byte[oFrameDataID3DIS.available()];
oFrameDataID3DIS.readFully(abyAdditionalData);
m_sAdditionalData = new String(abyAdditionalData);
}
}
catch (Exception e)
{
throw new InvalidFrameID3Exception(e);
}
}
public void accept(ID3Visitor oID3Visitor)
{
oID3Visitor.visitLINKID3V2Frame(this);
}
/** Set the contents of this frame.
*
* @param abyFrameIdentifier the frame identifier of the frame linked to
* @param sURL a reference to the location of the linked frame
* @param sAdditionalData any additional data which may be needed to retrieve the linked frame
* @throws ID3Exception if a frame identifier of four bytes is not specified, or if the URL is not specified
* @throws ID3Exception if this frame is in a tag with another LINK frame which would have the same contents
*/
public void setContents(byte[] abyFrameIdentifier, String sURL, String sAdditionalData)
throws ID3Exception
{
byte[] abyOrigFrameIdentifier = m_abyFrameIdentifier;
String sOrigURL = m_sURL;
String sOrigAdditionalData = m_sAdditionalData;
if (abyFrameIdentifier == null)
{
throw new ID3Exception("LINK frame requires frame identifier.");
}
if (abyFrameIdentifier.length != 4)
{
throw new ID3Exception("Frame identifiers must be four bytes in length in LINK frame.");
}
if ((sURL == null) || (sURL.length() == 0))
{
throw new ID3Exception("LINK frame requires an URL.");
}
m_abyFrameIdentifier = abyFrameIdentifier;
m_sURL = sURL;
m_sAdditionalData = sAdditionalData;
// try this update, and reverse it if it generates and error
try
{
notifyID3Observers();
}
catch (ID3Exception e)
{
m_abyFrameIdentifier = abyOrigFrameIdentifier;
m_sURL = sOrigURL;
m_sAdditionalData = sOrigAdditionalData;
throw e;
}
}
/** Get the frame identifier of the linked frame.
*
* @return the frame identifier bytes (which should be of length four)
*/
public byte[] getFrameIdentifier()
{
return m_abyFrameIdentifier;
}
/** Get the URL pointing to the location of the file containing the linked frame.
*
* @return the location url
*/
public String getLinkUrl()
{
return m_sURL;
}
/** Get any additional link-related data in this frame.
*
* @return any additional link-related data
*/
public String getAdditionalData()
{
return m_sAdditionalData;
}
protected byte[] getFrameId()
{
return "LINK".getBytes();
}
public String toString()
{
StringBuffer sbOutput = new StringBuffer();
sbOutput.append("Link: Frame identifier=[" + ID3Util.convertBytesToHexString(m_abyFrameIdentifier, true) +
"], URL=[" + m_sURL + "], Additional data=[" + m_sAdditionalData + "]");
return sbOutput.toString();
}
protected void writeBody(ID3DataOutputStream oIDOS)
throws IOException
{
// frame identifier
oIDOS.write(m_abyFrameIdentifier);
// url
oIDOS.write(m_sURL.getBytes());
oIDOS.writeUnsignedByte(0);
// additional data
oIDOS.write(m_sAdditionalData.getBytes());
}
public boolean equals(Object oOther)
{
if ((oOther == null) || (!(oOther instanceof LINKID3V2Frame)))
{
return false;
}
LINKID3V2Frame oOtherLINK = (LINKID3V2Frame)oOther;
return ( Arrays.equals(m_abyFrameIdentifier, oOtherLINK.m_abyFrameIdentifier) &&
(((m_sURL == null) && (oOtherLINK.m_sURL == null)) || m_sURL.equals(oOtherLINK.m_sURL)) &&
m_sAdditionalData.equals(oOtherLINK.m_sAdditionalData) );
}
}