meta.java

处理PDF

/*
 * $Id: Meta.java 3373 2008-05-12 16:21:24Z xlv $
 *
 * Copyright 1999, 2000, 2001, 2002 by Bruno Lowagie.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or 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 Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

package com.lowagie.text;

import java.util.ArrayList;

/**
 * This is an <CODE>Element</CODE> that contains
 * some meta information about the document.
 * <P>
 * An object of type <CODE>Meta</CODE> can not be constructed by the user.
 * User defined meta information should be placed in a <CODE>Header</CODE>-object.
 * <CODE>Meta</CODE> is reserved for: Subject, Keywords, Author, Title, Producer
 * and Creationdate information.
 *
 * @see		Element
 * @see		Header
 */

public class Meta implements Element {
    
    // membervariables
    
	/** This is the type of Meta-information this object contains. */
    private int type;
    
    /** This is the content of the Meta-information. */
    private StringBuffer content;
    
    // constructors
    
    /**
     * Constructs a <CODE>Meta</CODE>.
     *
     * @param	type		the type of meta-information
     * @param	content		the content
     */
    Meta(int type, String content) {
        this.type = type;
        this.content = new StringBuffer(content);
    }
    
    /**
     * Constructs a <CODE>Meta</CODE>.
     *
     * @param	tag		    the tagname of the meta-information
     * @param	content		the content
     */
    public Meta(String tag, String content) {
        this.type = Meta.getType(tag);
        this.content = new StringBuffer(content);
    }
    
    // implementation of the Element-methods
    
    /**
     * Processes the element by adding it (or the different parts) to a
     * <CODE>ElementListener</CODE>.
     *
     * @param	listener		the <CODE>ElementListener</CODE>
     * @return	<CODE>true</CODE> if the element was processed successfully
     */
    public boolean process(ElementListener listener) {
        try {
            return listener.add(this);
        }
        catch(DocumentException de) {
            return false;
        }
    }
    
    /**
     * Gets the type of the text element.
     *
     * @return	a type
     */
    public int type() {
        return type;
    }
    
    /**
     * Gets all the chunks in this element.
     *
     * @return	an <CODE>ArrayList</CODE>
     */
    public ArrayList getChunks() {
        return new ArrayList();
    }
    
	/**
	 * @see com.lowagie.text.Element#isContent()
	 * @since	iText 2.0.8
	 */
	public boolean isContent() {
		return false;
	}

	/**
	 * @see com.lowagie.text.Element#isNestable()
	 * @since	iText 2.0.8
	 */
	public boolean isNestable() {
		return false;
	}
    
    // methods
    
    /**
     * appends some text to this <CODE>Meta</CODE>.
     *
     * @param	string      a <CODE>String</CODE>
     * @return	a <CODE>StringBuffer</CODE>
     */
    public StringBuffer append(String string) {
        return content.append(string);
    }
    
    // methods to retrieve information

	/**
     * Returns the content of the meta information.
     *
     * @return	a <CODE>String</CODE>
     */
    public String getContent() {
        return content.toString();
    }

	/**
     * Returns the name of the meta information.
     *
     * @return	a <CODE>String</CODE>
     */
    
    public String getName() {
        switch (type) {
            case Element.SUBJECT:
                return ElementTags.SUBJECT;
            case Element.KEYWORDS:
                return ElementTags.KEYWORDS;
            case Element.AUTHOR:
                return ElementTags.AUTHOR;
            case Element.TITLE:
                return ElementTags.TITLE;
            case Element.PRODUCER:
                return ElementTags.PRODUCER;
            case Element.CREATIONDATE:
                return ElementTags.CREATIONDATE;
                default:
                    return ElementTags.UNKNOWN;
        }
    }
    
    /**
     * Returns the name of the meta information.
     * 
     * @param tag iText tag for meta information
     * @return	the Element value corresponding with the given tag
     */
    public static int getType(String tag) {
        if (ElementTags.SUBJECT.equals(tag)) {
            return Element.SUBJECT;
        }
        if (ElementTags.KEYWORDS.equals(tag)) {
            return Element.KEYWORDS;
        }
        if (ElementTags.AUTHOR.equals(tag)) {
            return Element.AUTHOR;
        }
        if (ElementTags.TITLE.equals(tag)) {
            return Element.TITLE;
        }
        if (ElementTags.PRODUCER.equals(tag)) {
            return Element.PRODUCER;
        }
        if (ElementTags.CREATIONDATE.equals(tag)) {
            return Element.CREATIONDATE;
        }
        return Element.HEADER;
    }

}