abstracttag.java

java+eclipse做的TTPlayer

     * @see com.hadeslee.jaudiotagger.tag.Tag#getFirstTrack()
     */
    public String getFirstTrack()
    {
        List l = getTrack();
        return (l.size() != 0) ? ((TagTextField) l.get(0)).getContent() : "";
    }

    /**
     * Get the first year or empty string if doesnt exist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#getFirstYear()
     */
    public String getFirstYear()
    {
        List l = getYear();
        return (l.size() != 0) ? ((TagTextField) l.get(0)).getContent() : "";
    }

    /**
     * Get the genres or empty list if none exist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#getGenre()
     */
    public List getGenre()
    {
        return get(getGenreId());
    }

    /**
     * Returns the identifier for a field representing the &quot;genre&quot;<br>
     *
     * @return identifier for the &quot;genre&quot; field.
     * @see TagField#getId()
     */
    protected abstract String getGenreId();

    /**
     * Get the titles or empty list if none exist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#getTitle()
     */
    public List getTitle()
    {
        return get(getTitleId());
    }

    /**
     * Returns the identifier for a field representing the &quot;title&quot;<br>
     *
     * @return identifier for the &quot;title&quot; field.
     * @see TagField#getId()
     */
    protected abstract String getTitleId();

    /**
     * Get the tracks or empty list if none exist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#getTrack()
     */
    public List getTrack()
    {
        return get(getTrackId());
    }

    /**
     * Returns the identifier for a field representing the &quot;track&quot;<br>
     *
     * @return identifier for the &quot;track&quot; field.
     * @see TagField#getId()
     */
    protected abstract String getTrackId();

    /**
     * Get the  years or empty list if none exist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#getYear()
     */
    public List getYear()
    {
        return get(getYearId());
    }

    /**
     * Returns the identifier for a field representing the &quot;year&quot;<br>
     *
     * @return identifier for the &quot;year&quot; field.
     * @see TagField#getId()
     */
    protected abstract String getYearId();

    /**
     * Does this tag contain any comon fields
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#hasCommonFields()
     */
    public boolean hasCommonFields()
    {
        return commonNumber != 0;
    }

    /**
     * Does this tag contain a field with the specified id
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#hasField(java.lang.String)
     */
    public boolean hasField(String id)
    {
        return get(id).size() != 0;
    }

    /**
     * Determines whether the given charset encoding may be used for the
     * represented tagging system.
     *
     * @param enc charset encoding.
     * @return <code>true</code> if the given encoding can be used.
     */
    protected abstract boolean isAllowedEncoding(String enc);

    /**
     * Is this tag empty
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#isEmpty()
     */
    public boolean isEmpty()
    {
        return fields.size() == 0;
    }

    /**
     * Set field
     *
     * Changed:Just because field is empty it doesnt mean it should be deleted. That should be the choice
     * of the developer. (Or does this break things)
     *
     * @see com.hadeslee.jaudiotagger.tagcom.hadeslee.jaudiotaggerdiotagger.tag.TagField)
     */
    public void set(TagField field)
    {
        if (field == null)
        {
            return;
        }

        // If there is already an existing field with same id
        // and both are TextFields, we replace the first element
        List<TagField> list = fields.get(field.getId());
        if (list != null)
        {
            list.set(0,field);
            return;
        }

        // Else we put the new field in the fields.
        list = new ArrayList<TagField> ();
        list.add(field);
        fields.put(field.getId(), list);
        if (field.isCommon())
        {
            commonNumber++;
        }
    }

    /**
     * Set or add album
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setAlbum(java.lang.String)
     */
    public void setAlbum(String s)
    {
        set(createAlbumField(s));
    }

    /**
     * Set or add artist
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setArtist(java.lang.String)
     */
    public void setArtist(String s)
    {
        set(createArtistField(s));
    }

    /**
     * Set or add comment
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setComment(java.lang.String)
     */
    public void setComment(String s)
    {
        set(createCommentField(s));
    }

    /**
     * Set or add encoding
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setEncoding(java.lang.String)
     */
    public boolean setEncoding(String enc)
    {
        if (!isAllowedEncoding(enc))
        {
            return false;
        }

        Iterator it = getFields();
        while (it.hasNext())
        {
            TagField field = (TagField) it.next();
            if (field instanceof TagTextField)
            {
                ((TagTextField) field).setEncoding(enc);
            }
        }

        return true;
    }

    /**
     * Set or add genre
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setGenre(java.lang.String)
     */
    public void setGenre(String s)
    {
        set(createGenreField(s));
    }

    /**
     * Set or add title
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setTitle(java.lang.String)
     */
    public void setTitle(String s)
    {
        set(createTitleField(s));
    }

    /**
     * Set or add track
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setTrack(java.lang.String)
     */
    public void setTrack(String s)
              throws FieldDataInvalidException
    {
        set(createTrackField(s));
    }

    /**
     * Set or add year
     *
     * @see com.hadeslee.jaudiotagger.tag.Tag#setYear(java.lang.String)
     */
    public void setYear(String s)
    {
        set(createYearField(s));
    }

    /**
     * (overridden)
     *
     * @see java.lang.Object#toString()
     */
    public String toString()
    {
        StringBuffer out = new StringBuffer();
        out.append("Tag content:\n");
        Iterator it = getFields();
        while (it.hasNext())
        {
            TagField field = (TagField) it.next();
            out.append("\t");
            out.append(field.getId());
            out.append(":");
            out.append(field.toString());
            out.append("\n");
        }
        return out.toString().substring(0, out.length() - 1);
    }

    //Should be overridden by all subclasses but provided empty impl
    //as working one format at a time
    //TODO remove
    public TagField createTagField(TagFieldKey genericKey, String value)
             throws KeyNotFoundException,FieldDataInvalidException
    {
        return null;
    }

    //Should be overridden by all subclasses but provided empty impl
    //as working one format at a time
    //TODO remove
    public String getFirst(TagFieldKey genericKey)throws KeyNotFoundException
    {
        return null;
    }

    //Should be overridden by all subclasses but provided empty impl
    //as working one format at a time
    //TODO remove
    public void deleteTagField(TagFieldKey tagFieldKey)
            throws KeyNotFoundException
    {
        ;
    }


    /**
     * Delete all ocurrences of field.
     *
     * @param key
     */
    protected void deleteField(String key)
    {
        Object removed = fields.remove(key);
        //if (removed != null && field.isCommon())
        //    commonNumber--;
        return;
    }

     /**
     * Creates a field which represents the &quot;album&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;album&quot;
     */
    public abstract TagField createAlbumField(String content);

    /**
     * Creates a field which represents the &quot;artist&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;artist&quot;
     */
    public abstract TagField createArtistField(String content);

    /**
     * Creates a field which represents the &quot;comment&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;comment&quot;
     */
    public abstract TagField createCommentField(String content);

    /**
     * Creates a field which represents the &quot;genre&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;genre&quot;
     */
    public abstract TagField createGenreField(String content);

    /**
     * Creates a field which represents the &quot;title&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;title&quot;
     */
    public abstract TagField createTitleField(String content);

    /**
     * Creates a field which represents the &quot;track&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;track&quot;
     */
    public abstract TagField createTrackField(String content)
              throws FieldDataInvalidException;

    /**
     * Creates a field which represents the &quot;year&quot;.<br>
     * The field will already contain the given content.
     *
     * @param content The content of the created field.
     * @return tagfield representing the &quot;year&quot;
     */
    public abstract TagField createYearField(String content);
}