abstractstring.java

java+eclipse做的TTPlayer

/**
 *  @author : Paul Taylor
 *  @author : Eric Farng
 *
 *  Version @version:$Id: AbstractString.java,v 1.9 2007/08/07 14:36:14 paultaylor Exp $
 *
 *  MusicTag Copyright (C)2003,2004
 *
 *  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,
 *  you can get a copy from http://www.opensource.org/licenses/lgpl-license.php or write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Description:
 *
 */
package com.hadeslee.audiotag.tag.datatype;

import com.hadeslee.audiotag.tag.id3.AbstractTagFrameBody;
import com.hadeslee.audiotag.tag.id3.valuepair.TextEncoding;

import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

/** A partial implementation for String based ID3 fields */
public abstract class AbstractString
    extends AbstractDataType
{
     /**
     * Creates a new  datatype
     *
     * @param identifier
     * @param frameBody
     */
    protected AbstractString(String identifier, AbstractTagFrameBody frameBody)
    {
        super(identifier, frameBody);
    }

    /**
     * Creates a new  datatype, with value
     *
     * @param identifier
     * @param frameBody
     */
    public AbstractString(String identifier, AbstractTagFrameBody frameBody,String value)
    {
        super(identifier, frameBody,value);
    }

    /**
     * Copy constructor
     * 
     * @param object
     */
    protected AbstractString(AbstractString object)
    {
        super(object);
    }

    /**
     * Return the size in bytes of this datatype as it was/is held in file this
     * will be effected by the encoding type.
     *
     * @return the size
     */
    public int getSize()
    {
        return size;
    }

    /**
     * Sets the size in bytes of this datatype.
     * This is set after writing the data to allow us to recalculate the size for
     * frame header.
     *
     */
    protected void setSize(int size)
    {
        this.size = size;
    }

    /**
     * Return String representation of datatype
     *
     * @return a string representation of the value
     */
    public String toString()
    {
        return (String) value;
    }

    /**
     * Check the value can be encoded with the specified encoding
     */
    public boolean canBeEncoded()
    {
        //Try and write to buffer using the CharSet defined by the textEncoding field.
        byte textEncoding = this.getBody().getTextEncoding();
        String charSetName = TextEncoding.getInstanceOf().getValueForId(textEncoding);
        CharsetEncoder encoder = Charset.forName(charSetName).newEncoder();

        if (encoder.canEncode((String) value) == true)
        {
            return true;
        }
        else
        {
            logger.finest("Failed Trying to decode" + (String) value + "with" + encoder.toString());
            return false;
        }           
    }
}